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Review

Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications

by
Mahadevamurthy Murali
1,
Nataraj Kalegowda
1,
Hittanahallikoppal G. Gowtham
2,
Mohammad Azam Ansari
3,*,
Mohammad N. Alomary
4,
Saad Alghamdi
5,
Natarajamurthy Shilpa
2,6,
Sudarshana B. Singh
2,
M. C. Thriveni
7,
Mohammed Aiyaz
2,
Nataraju Angaswamy
8,
Nanjaiah Lakshmidevi
6,
Syed F. Adil
9,
Mohammad R. Hatshan
9 and
Kestur Nagaraj Amruthesh
1,*
1
Applied Plant Pathology Laboratory, Department of Studies in Botany, University of Mysore, Manasagangotri, Mysuru 570006, Karnataka, India
2
Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysuru 570006, Karnataka, India
3
Department of Epidemic Disease Research, Institutes for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
4
National Center for Biotechnology, Life Science and Environmental Research Institute, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442, Saudi Arabia
5
Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah P.O. Box 715, Saudi Arabia
6
Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysuru 570006, Karnataka, India
7
Central Sericultural Germplasm Resources Centre, Central Silk Board, Ministry of Textiles, Thally Road, TVS Nagar, Hosur 635109, Tamil Nadu, India
8
Department of Biochemistry, Karnataka State Open University, Mukthagangotri, Mysuru 570006, Karnataka, India
9
Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
*
Authors to whom correspondence should be addressed.
Pharmaceutics 2021, 13(10), 1662; https://doi.org/10.3390/pharmaceutics13101662
Submission received: 9 September 2021 / Revised: 6 October 2021 / Accepted: 6 October 2021 / Published: 11 October 2021
(This article belongs to the Special Issue Advanced Nanoscience of Biomaterials for Biomedical Applications)

Abstract

:
Zinc oxide nanoparticles have become one of the most popular metal oxide nanoparticles and recently emerged as a promising potential candidate in the fields of optical, electrical, food packaging, and biomedical applications due to their biocompatibility, low toxicity, and low cost. They have a role in cell apoptosis, as they trigger excessive reactive oxygen species (ROS) formation and release zinc ions (Zn2+) that induce cell death. The zinc oxide nanoparticles synthesized using the plant extracts appear to be simple, safer, sustainable, and more environmentally friendly compared to the physical and chemical routes. These biosynthesized nanoparticles possess strong biological activities and are in use for various biological applications in several industries. Initially, the present review discusses the synthesis and recent advances of zinc oxide nanoparticles from plant sources (such as leaves, stems, bark, roots, rhizomes, fruits, flowers, and seeds) and their biomedical applications (such as antimicrobial, antioxidant, antidiabetic, anticancer, anti-inflammatory, photocatalytic, wound healing, and drug delivery), followed by their mechanisms of action involved in detail. This review also covers the drug delivery application of plant-mediated zinc oxide nanoparticles, focusing on the drug-loading mechanism, stimuli-responsive controlled release, and therapeutic effect. Finally, the future direction of these synthesized zinc oxide nanoparticles’ research and applications are discussed.

1. Introduction

Nanotechnology is a branch of science concerned with the processing and modification of materials at the nanometer scale. It is a product of nature that influences a material through physiochemical processes, and it has a wide range of applications in research [1,2,3,4]. At Caltech, Richard Feynman, the greatest theoretical physicist, was the first to communicate the idea of nanotechnology in 1959. Nanomaterials are microscopic materials with nanometer dimensions that are in use in different fields. They have distinct properties, such as a large surface area and quantum size effects, and are regarded as a significant state of matter [5]. Metal and metal oxide nanoparticles have many promising applications in agriculture, catalysts, electronics, fiber optics, sensors, biolabeling, and biomedical fields [6,7,8,9,10,11]. In the synthesis of nanoparticles, chemical methods often result in dangerous byproducts, and the chemical reducing reagents (such as hydrazine, sodium borohydride, and sodium dodecyl sulfate) used are toxic to nature. Hence, in comparison to the chemical methods, the eco-friendly green synthesis method has gained significant attention in the past decade for the synthesis of nanoparticles [4,8,12].
The synthesis of nanoparticles through biogenic methods involves the use of a variety of natural resources that include all forms of plants and microorganisms. During the synthesis of nanoparticles by biological route, active enzymes/biomolecules (active metabolites/phytochemicals) of the biotic source act as reducing and capping agents, thereby allowing for the mass production of the particles [1,13,14]. The usage of biotic sources not only reduces the risk of toxicity of the obtained particles to the environment but can also be produced in a large scale with the required parameters (well-defined size and morphology) [2,15,16]. Among the various metal nanoparticles synthesized through the usage of various biotic sources, zinc oxide nanoparticles synthesized through plant extracts have gained considerable importance in the present millennium due to their unique properties and various biomedical applications.

2. Zinc Oxide Nanoparticles

Zinc oxide is a unique inorganic material with semiconducting behavior and piezoelectric, triboelectric, pyroelectric, optoelectronics, and catalysts properties [12,17,18,19,20]. Zinc oxide is an n-type semiconductor with a band gap of 3.4 eV and an excitation binding energy of 60 meV at room temperature. Zinc oxide is nontoxic and skin-friendly, and it is even used as a UV blocker in sunscreens. Among the metal oxide nanoparticles, zinc oxide nanoparticles have been extensively used in various biological applications due to their nontoxic nature, and they are also listed as “generally recognized as safe” (GRAS) by the U.S. FDA (21CFR182.8991). Various studies have established zinc oxide as the most effective antimicrobial agent, as evidenced by releasing reactive oxygen species (ROS) on its surface [17].
Meanwhile, zinc oxide is known to be biocompatible and safe, with various applications in biomedical and drug delivery systems. Among the metal oxide nanoparticles, zinc oxide nanoparticles have piqued the interest of researchers for the past two decades due to their unique and wide range of properties. Due to their biocompatible nature, they are widely used as a semiconductor nanomaterial in ethanol gas sensors, photocatalysis, electronic and optoelectronic devices, pharmaceutical and cosmetic products, and, particularly, in the biomedicine field [10,20,21]. It has been well-documented that zinc oxide nanoparticles can be synthesized by different methods using various types of biotic sources, but the present review mainly focuses on the biosynthesis of zinc oxide nanoparticles using plant sources that are termed to be eco-friendly, cost-effective, and, also, efficient in biomedical applications, along with advances made in the “new millennium” towards understanding their role/mechanism of action involved.

3. Synthesis of Zinc Oxide Nanoparticles from Plants

Green synthesis is an emerging area in which nontoxic chemicals are generated using environmentally friendly and bio-safe reagents and may also be considered as a viable alternative to the physical and chemical methods. However, the main problems with green synthesis are nanoparticle stability and a lack of understanding of its mechanisms. Researchers are focusing their efforts on the green synthesis of metal and metal oxide nanoparticles from various biological sources such as plants, bacteria, fungi, yeast, algae, etc. [22,23,24,25]. Among the different sources, plants are considered to be vastly available and are known to possess phytoconstituents that are reported to be beneficial in various ways to humankind [26,27,28,29]. Plant parts such as leaves, stems, bark, roots, rhizomes, fruits, flowers, and seeds have been extensively used for the synthesis of zinc oxide nanoparticles in the recent past and are found to be stable, highly pure, cost-effective, and possess greater biomedical properties [30,31]. Plants are the most popular choice for nanoparticle synthesis, because they produce large quantities of stable, varied-sized nanoparticles for specific applications on a large scale [20,32,33]. Plant phytochemicals such as polysaccharides, proteins, amino acids, alkaloids, flavonoids, and terpenoids are used as stabilizing agents in green synthesis methods to biologically reduce metal oxides (or metal ions) to metal nanoparticles in an aqueous solution [5,25,34].
The green synthesis of zinc oxide nanoparticles from plant sources usually begins with the washing of plant parts using double-distilled water or Tween 20, accompanied by drying at room temperature and grinding into powder with a mortar and pestle. The plant extract is prepared by boiling the weighted powder with continuous stirring with a magnetic stirrer. The solution is then filtered through Whatman filter paper and used as a plant extract in the following steps. Zinc precursors such as zinc acetate [Zn(OAc)2], zinc chloride [ZnCl2], zinc nitrate [Zn(NO3)2] and zinc sulphate [ZnSO4] solutions are individually used with a fixed amount of plant extract, and it serves as the source for preparing zinc oxide nanoparticles through the application of various methods that involve heating, centrifugation, etc. that finally results in the formation of the desired nanoparticles [35,36,37,38,39,40]. Further, UV–Vis spectroscopy was used to confirm the nanoparticles that were synthesized. The morphology of the nanoparticles was determined using electron microscopes such as the Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Atomic Force Microscopy (AFM). The nanoparticles’ crystal structure and chemical composition were calculated using X-Ray Diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDS or EDX) used for determination of the elements present, and Fourier-transform infrared (FTIR) spectroscopy used to describe the functional groups present on the surfaces of the nanoparticles. The Dynamic Light Scattering (DLS) and Zeta Potential (ZP) methods were used to determine the size and dispersion of the nanoparticles in a liquid suspension.
It is well-documented that the ability of any organism to reduce metal ions apart from stabilizing them into nanoparticles is the basis for green synthesis. Plants are considered to be the best candidates for the green synthesis of nanoparticles, as they produce stable forms of the same compared to microorganisms [41]. Plants are considered to possess a rich biodiversity of secondary metabolites that are worth investigating. In the recent past, researchers were interested in the phytoconstituents produced by plants to investigate their bio-reduction process of metal nanoparticles by combinations of phytoconstituents/secondary metabolites [42]. These molecules not only acted as reducing agents but also played a key role in the capping of nanoparticles, which was crucial for their stability and biocompatibility, and due to these molecules, no extra chemical reducing and capping agents were required [4]. In addition, these plant-based molecules not only operated as the growth terminator of zinc oxide nanoparticles but also acted as a linker molecule between two or more molecules of zinc oxide-formed ZnO NPs, making them self-assemble [43].
Although many reports are available on the bioactivities (such as antimicrobial, antioxidant, anticancer, photocatalytic, etc.) of zinc oxide nanoparticles synthesized from various plant species, a few studies have been conducted to compare the activities of nanoparticles from different plants [12,44,45,46]. In addition, it is also noted that the plant-mediated zinc oxide nanoparticles possessed better biological activities than the nanoparticles synthesized through the chemical route [12,28,44,47,48]. Further, it has been noted that, due to the coating of various pharmacologically active biomolecules on their surface, zinc oxide nanoparticles allow multiple ligand-based conjugations of nanoparticles with their respective receptors, leading to better bioactivities [3,4,12,14,45,46,47,49,50]. These comparisons have suggested that zinc oxide nanoparticles possess better bioactivities when they are synthesized from the potential reducing agents present in the plants. Table 1 lists the different plant sources used in zinc oxide nanoparticles synthesis, along with their morphological characteristics and applications.

4. Biomedical Applications of Plant-Mediated Zinc Oxide Nanoparticles

4.1. Antibacterial Activity

Bacterial infections are a major threat to humanity’s health. Researchers have focused on metal and metal oxide nanoparticles as antibacterial agents due to the increased antibiotic resistance in bacteria and the emergence of new strains [2]. Zinc oxide nanoparticles have been studied extensively as antibacterial agents due to their unique physiochemical properties and increased surface areas [4]. Furthermore, zinc oxide nanoparticles are both safe and compatible with the human body. Numerous publications describe the possible antibacterial mechanisms of zinc oxide nanoparticles, which involves (1) the production of ROS (i.e., OH (hydroxyl radical) and O2−2 (peroxide)), which induces oxidative stress, cell membrane disruption, and DNA damage, resulting in the death of bacterial cells; (2) the dissolution of zinc oxide nanoparticles into the release of Zn2+ ions, which interact with the bacterial cell, especially the cell membrane, cytoplasm, and nucleic acid, thus disintegrating the cellular integrity and resulting in bacterial cell death; and (3) direct interactions between zinc oxide nanoparticles and bacterial cell membranes through electrostatic forces that damage the plasma membrane and cause a leakage of intracellular components [30] (Figure 1).
In our previous study, zinc oxide nanoparticles synthesized from leaf extracts of Ceropegia candelabrum with zinc nitrate (as a precursor) by the hydrothermal process resulted in nanoparticles of high purity, a hexagonal wurtzite shape, and 12–35-nm sizes [5]. The biosynthesized zinc oxide nanoparticles significantly showed antibacterial potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella typhi at 100 μg·mL−1. One of our research groups also bio-fabricated zinc oxide nanoparticles from leaf extracts of Cochlospermum religiosum to study their antibacterial potentiality [82]. The bio-fabricated zinc oxide nanoparticles significantly exhibited the inhibition of Gram-positive (B. subtilis and S. aureus) and Gram-negative (Pseudomonas aeruginosa and E. coli) bacteria with minimum inhibitory concentrations (MIC) of 4.8–312.5 μg·mL−1. The antibacterial potency of zinc oxide nanoparticles is probably due to their small size, which is more likely to damage the membrane, penetrate the cytoplasm, and produce numerous ROS that can damage the DNA and other cellular components of bacteria [31,80].
The difference in antibacterial activity can be associated with the structural and chemical compositions of the bacterial cell membranes [2]. Sharma et al. [127] studied the effect of the shape and size of zinc oxide nanoparticles synthesized by using Aloe vera leaf extracts on their antibacterial activity and reported that cuboidal (40–45 nm)-shaped nanoparticles were shown to be more protuberant in antibacterial activity when compared to spherical (60–180 nm) and hexagonal (~65 nm)-shaped nanoparticles. Due to the small size of biosynthesized zinc oxide nanoparticles, they provide a high surface area, which leads to more interactions between nanoparticles and bacterial cells, which can be used as an antibacterial agent even at lower dosages. Biosynthesized zinc oxide nanoparticles initially interact with the bacterial plasma membrane, causing nanoparticles to enter the cytoplasm and release metal ions, thereby disrupting the membrane permeability and, finally, causing DNA damage, leading to the death of bacterial cells [71]. The antibacterial activity demonstrated by zinc oxide nanoparticles synthesized from leaf extracts of Cassia fistula and Melia azadarach have a substantial ability to suppress clinical pathogens (such as E. coli and S. aureus) compared to traditional drugs, and it was concluded that the synthesis of nanoparticles employing the extracts of medicinal plants could be effective in the treatment of various human infectious diseases [126]. Recently, Faisal et al. [11] showed that 1% zinc oxide nanoparticles (1 mg mL−1) synthesized from aqueous fruit extracts of Myristica fragrans were found to display the maximum zone of inhibition against Klebsiella pneumoniae, E. coli, P. aeruginosa, and S. aureus. Further, the antibacterial efficacy of plant-mediated zinc oxide nanoparticles against various bacterial pathogens is listed in Table 2.

4.2. Antifungal Activity

In addition to antibacterial activity, zinc oxide nanoparticles also possess antifungal activity against many harmful fungi and yeasts, making them promising antifungal food additives [19,103]. The possible mechanisms of antifungal activity of zinc oxide nanoparticles are described for zinc oxide nanoparticles that can enter fungal (conidial) cells by diffusion and endocytosis; they interfere in the mitochondrial function and promote ROS production Zn2+ ion release inside the cytoplasm. The excess production of ROS and Zn2+ ions released from zinc oxide nanoparticles can penetrate the nuclear membrane and cause irreversible DNA damage, inducing cell death [134,135] (Figure 2). The role of the electronic band gap (Eg) property of zinc oxide nanoparticles with the redox potential (EH) of numerous ROS generation reactions have also been proposed [134]. Zinc oxide nanoparticles electrons (e), when excited with energy higher than Eg, are promoted across the band gap energy to the conduction band edge (Ec), which creates a hole (h+) in the valence band (Ev). The e in Ec and holes in Ev exhibit high reducing and oxidizing power, respectively. The e reacts with molecular oxygen (O2) to produce superoxide anion (O2•–) through sequential reduction reactions. The h+ can extract e from water (H2O) and/or hydroxyl ions to generate hydroxyl radical (OH).
The zinc oxide nanoparticles synthesized from flower extracts of Nyctanthes arbor-tristis demonstrated antifungal activity against fungal phytopathogens (such as Fusarium oxysporum, Botrytis cinerea, Penicillium expansum, Alternaria alternata, and Aspergillus niger) with the lowest MIC value of 16 μg·mL−1, suggesting that they could be used to develop antifungal agents for commercial use in agriculture [32]. Similarly, Khan et al. [39] suggested that zinc oxide nanoparticles synthesized using Trianthema portulacastrum extracts were found to exhibit antifungal properties against Aspergillus niger, A. flavus, and A. fumigatus. Additionally, zinc oxide nanoparticles synthesized from different plant extracts such as Beta vulgaris, Cinnamomum tamala, C. verum, and Brassica oleracea were found effective against Candida albicans and A. niger [25]. Furthermore, the plant-mediated zinc oxide nanoparticles that were effective antifungal agents against various fungal pathogens are provided in Table 2.

4.3. Antioxidant Activity

The antioxidant activity of zinc oxide nanoparticles is attributed to their smaller size, but another explanation may be a phenomenon in 2,2-diphenyl-1-picrylhydrazyl (DPPH) where the electron density is transferred from the oxygen atom to the odd electron located at the nitrogen atom, resulting in a decrease in the n → π* transition intensity at 517 nm. The antioxidant activity’s mechanism involves the unstable deep violet-colored methanolic solution of DPPH, which turns into stable pale-yellow color with the addition of zinc oxide nanoparticles due to their DPPH free radical scavenging activity through the transfer of an electron from the oxygen atom to the odd electron of a nitrogen atom, resulting in stable DPPH molecule formation (Figure 3) [83]. In other words, the antioxidant property of zinc oxide nanoparticles is determined by their ability to donate hydrogen. Furthermore, even in the absence of UV light, the formation of a large number of electron and hole pairs on the surfaces of zinc oxide nanoparticles results in a high redox potential that splits water (H2O) molecules into hydroxyl (OH) and hydrogen (H) radicals, which are available for DPPH free radical reduction and DPPH molecule stability [17,83,124].
Our previous study reported that the antioxidant activity of biosynthesized zinc oxide nanoparticles from C. candelabrum showed significantly DPPH free radical scavenging activity from 0% to 55%, with an IC50 value of 95.09 μg·mL−1, compared with the 75% inhibition offered by ascorbic acid (a positive control) at 50 μg·mL−1 [5]. It is also reported that an increased antioxidant activity was observed with an increase in the zinc oxide nanoparticle concentration. According to the findings of Khan et al. [39], the green synthesized zinc oxide nanoparticles had a strong antioxidant activity due to their charge density and capping materials on their surface. Alamdari et al. [83] revealed that zinc oxide nanoparticles biosynthesized from leaf extracts of Sambucus ebulus were found to exhibit H2O2free radical scavenging activity with an IC50 value of 43 μg·mL−1 and concluded that the presence of metal or Zn ions in the structure could enhance the antioxidant capabilities of the biosynthesized zinc oxide nanoparticles. Recently, Faisal et al. [11] revealed that zinc oxide nanoparticles synthesized from the aqueous fruit extracts of M. fragrans were found to show excellent free radical scavenging irrespective of the methods employed, viz., ABTS (82.12% TEAC), DPPH (66.3% FRSA), TAC (71.1 μg AAE·mg−1), and TRP (63.41 μg AAE·mg−1). In accordance with the above findings, the antioxidant efficacy of plant-mediated zinc oxide nanoparticles is represented in Table 3.

4.4. Antidiabetic Activity

Diabetes is a complex disease that requires an effective multifaceted treatment approach to care for patients. Antidiabetic medications are often used in conjunction with insulin or other drugs, resulting in higher medication costs overall. Zinc supplementation has been shown to improve glycemic regulation in diabetic humans and animals [33,66]. Furthermore, this metal can boost diabetic problems such as nephropathy and cardiomyopathy [35]. Due to their capacity to deliver Zn2+ ions, zinc oxide nanoparticles are currently being studied to treat diabetes and diabetic complications. The antidiabetic properties of zinc oxide nanoparticles are an antihyperglycemic effect, i.e., improving the glucose tolerance, enhancement of pancreatic functions (through the regulation of main pancreatic hormones, namely insulin and glucagon), upregulation of glucose transporters and biosensors to regulate insulin secretion, weight maintenance, anti-dyslipidemic effect (i.e., improve dyslipidemia), anti-inflammatory, inhibition of α-amylase and α-glucosidase activities for lowering the post-prandial rise of blood glucose levels, and improving the insulin sensitivity and antioxidative system to eradicate ROS-induced oxidative stress [138] (Figure 4).
The inhibition of carbohydrate metabolizing enzymes (such as α-amylase and α-glucosidase) is a unique strategy for controlling blood sugar, and it requires a large number of compounds to be evaluated in order to rule out inactive molecules and save time and money. In vitro α-amylase and α-glucosidase inhibitory studies revealed that zinc oxide nanoparticles synthesized from Tamarindus indica extract had the highest inhibitory activity compared to the zinc oxide nanoparticles synthesized from other plant extracts [22]. Additionally, Rajakumar et al. [34] confirmed that the synthesized zinc oxide nanoparticles from Andrographis paniculata leaf extract displayed better antidiabetic potential in terms of α-amylase inhibition activity with aIC50 value of 121.42 μg·mL−1. Similarly, the zinc oxide nanoparticles synthesized from Costus igneus leaf extract were found to show more effective antidiabetic activity, wherein the percentage of inhibition ranged from 20% to 74% for α-amylase and 36% to 82% for α-glucosidase at aconcentration of 20–100 μg·mL−1 of nanoparticles [33]. Recently, Faisal et al. [11] indicated that an excellent α-amylase (73.23%) and α-glucosidase (65.21%) inhibition activity at 400 μg·mL−1 was offered by zinc oxide nanoparticles synthesized from aqueous fruit extracts of M. fragrans and revealed that the bio-based nanoparticles could have strong antidiabetic properties and are considered a useful therapeutic agent for the treatment of diabetes as a replacement for expensive and ineffective medicines. Additionally, other reports on the efficacy of antidiabetic activity by plant-mediated zinc oxide nanoparticles are listed in Table 4.

4.5. Anticancer Activity

The therapeutic regimes cannot distinguish between cancerous and normal cells, resulting in systemic toxicity and side effects. As a result, new chemotherapeutic agents with high selectivity for cancer cells are needed. Zinc deficiency initiates and facilitates the development of cancerous cells, as it is an important mineral that maintains homeostasis by controlling the enzyme activities in our body [104]. Zinc is essential for the function of p-53 (a tumor suppressor gene) that controls apoptosis by activating the Caspase-6 (Casp6) enzyme. In addition, zinc oxide nanoparticles have a special electrostatic property that aids in the selective targeting of cancer cells. Anionic phospholipids are abundant on the surface of cancer cells, resulting in electrostatic attraction with zinc oxide nanoparticles, which encourages cancer cells to take up zinc oxide nanoparticles, resulting in cytotoxicity in cancer cells [70,129].
The small size of zinc oxide nanoparticles, on the other hand, aids in the permeation and retention of nanoparticles within tumorous cells, allowing them to act. The possible mechanisms behind zinc oxide nanoparticles’ selective pH-responsive cytotoxicity towards cancer cells are (1) the pH-dependent rapid dissolution of zinc oxide nanoparticles into the release of Zn2+ ions under an acidic intracellular environment, which causes oxidative stress (via ROS production) and subsequent cell damage within cancer cells, and (2) the production of a large amount of ROS in cancer cells relative to normal cells; the elevated ROS level then causes mitochondrial dysfunction and activates the intrinsic mitochondrial apoptotic pathway (Figure 5) (Sana et al. [71]. ROS can also mediate cell death via extrinsic necrosis and apoptosis. Further, the overproduction of ROS leads to induced oxidative DNA damage and mitotic death and can also trigger autophagic/mitophagic cell death [19,26]. The MTT assay has been effectively used to confirm the anticancer activity of zinc oxide nanoparticles prepared using the plant-mediated green synthesis method against a variety of cell lines, which are detailed in Table 5. In addition, zinc oxide nanoparticles have been used successfully as an effective carrier to deliver anticancer drugs to tumor cells.
Zinc oxide nanoparticles have a particle size, shape, surface charge, concentration, and time-dependent cytotoxicity in cancer cells, and photo-irradiation with ultraviolet (UV) or near-infrared (NIR) lasers enhance its anticancer activity through a synergistic chemo-photodynamic effect [29,71]. The majority of the researchers also demonstrated that zinc oxide nanoparticles are less or nontoxic compared to normal cells in vitro when used in the same concentration range as cancer cells. Zinc oxide nanoparticles can cause systemic toxicity in tumor-bearing mouse models. However, using antioxidants in combination with zinc oxide nanoparticles may minimize the toxic side effects and increase the antitumor potential [11]. Zinc oxide nanoparticles’ adverse toxic side effects can also be prevented or decreased by using cancer cell-specific ligands. While numerous reports on the anticancer properties of plant-mediated green synthesized zinc oxide nanoparticle in vitro systems are available, only a few studies in tumor-bearing mouse models have been performed [93]. In vivo tumor models can be used to conduct further research using plant-mediated green synthesized zinc oxide nanoparticles with active cancer cell-targeting strategies.
The semiconducting nature of biosynthesized zinc oxide nanoparticles has been reported to induce cytotoxicity in cancer cells by forming ROS on the particle’s surface; the released Zn2+ ions are dissolved in culture media, indicating the direct interaction of nanoparticles with a cancer cell membrane, resulting in oxidative stress and, ultimately, cancer cell death [71]. Zinc oxide nanoparticles synthesized from the aqueous extract of Deverra tortuosa exhibited enticing selective cytotoxic efficacy against two cancer lines (Caco-2 and A549), providing appealing ‘safer and cheaper’ alternatives to traditional therapy regimens [99]. Faisal et al. [11] used the Streptomyces 85E strain to elucidate the protein kinase inhibition capability of zinc oxide nanoparticles synthesized from aqueous fruit extracts of M. fragrans and concluded that the plant extracts provide crucial capping and stabilizing agents to biogenic nanoparticles, which are responsible for their anticancer properties. Recently, Umamaheswari et al. [29] reported that the anticancer activity of zinc oxide nanoparticles biosynthesized from leaf extracts of Raphanus sativus was higher after treating the A549 cell lines, indicating that cancer drugs can be prepared using this environmentally friendly method. The DNA damage pathways, paraptosis, autophagy, radio sensitizing, aberrant cellular metabolism, overcoming chemo resistance, oxidative stress modulation, induction of apoptosis, arresting of the cancer cell cycle, anti-invasion, and metastasis are some of the possible anticancer mechanisms that have been reported so far [139].

4.6. Anti-Inflammatory Activity

Nanoparticles have been widely exploited as a potential anti-inflammatory agent in recent years. The large surface area-to-volume ratio causes nanoparticles to have more surface reactive properties, resulting in more interactions with the cell membrane and easier transport within the membrane [34,97,125]. Zn is easily transported through the cell membrane because of the nanosizes of zinc oxide nanoparticles. The anti-inflammatory mechanisms adopted by zinc oxide nanoparticles involve the release of Zn2+ ions from the dissolution of zinc oxide nanoparticles and subsequent block of the release of proinflammatory cytokines (like interleukin-1 (IL-1), interleukin-1β (IL-1β), interleukin-13 (IL-13), and tumor necrosis factor-α (TNF-α)) in mast cells; they suppress the expression of the lipopolysaccharide (LPS)-induced cyclooxygenase-2 (COX-2) gene in macrophages to prevent the release of prostaglandin-E2 (PG-E2), suppress the expression of inducible nitric oxide synthase (iNOS) to reduce nitric oxide (NO) production, inhibit myeloperoxidase (MPO) for the upregulation of inflammatory pathogenesis, inhibit the nuclear factor-kappa B (NF-κβ) pathway and block the caspase-1 enzyme in activated mast cells, inhibit the proliferation of mast cells through the regulation of the p-53 protein level to prevent the release of High Mobility Group Protein-1 (HMG-1), and also, inhibit thymic stromal lymphopoietin (TSLP) production by primary epithelial cells [140] (Figure 6).
The zinc oxide nanoparticles synthesized from Polygala tenuifolia root extract displayed excellent anti-inflammatory activity, even up to 1 mg·mL−1, by suppressing the LPS-induced mRNA and protein expressions of iNOS; COX-2; and anti-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in LPS-stimulated RAW 264.7 murine macrophage cells in a dose-dependent manner [17]. Agarwal and Shanmugam [21] also revealed that green synthesized zinc oxide nanoparticles from Kalanchoe pinnata leaf extract were found to be biocompatible up to 1 mg·mL−1 and to have an anti-inflammatory effect by inhibiting the production and release of proinflammatory mediators such as IL-1β, IL-6, TNF-α, and COX-2. Likewise, Liu et al. [125] proved the anti-inflammatory effects of synthesized zinc oxide nanoparticles from Vernonia amygdalina leaf extract against different pain and inflammation-induced mice. Moreover, the synthesized zinc oxide nanoparticles were found to exhibit potent anti-inflammatory effects via reducing the inflammatory response and proinflammatory cytokines level in mice. Other reports on the anti-inflammatory properties of plant-mediated zinc oxide nanoparticles are summarized in Table 6.

4.7. Photocatalytic Activity

To prevent water pollution, various semiconductors, including zinc oxide, have been evaluated as photocatalysts and have proposed a viable solution. Zinc oxide nanoparticles synthesized from biological origin have shown a remarkable photocatalytic degradation of several dyes, including methylene blue, methyl orange, etc., due to their intrinsic ability to absorb UV irradiation and optical transparency. Since methylene blue is a major water pollutant emitted by industries such as textiles and is widely recognized as a traditional organic pollutant, these zinc oxide nanoparticles have gained much publicity due to environmental concerns [92,110,130]. Furthermore, the toxic effluents discharged by the textile industry have harmed marine life and the ecosystem, resulting in a serious environmental crisis. The bio-fabricated zinc oxide nanoparticles were utilized as a photocatalyst to degrade carcinogen organic dyes where the structure, particle size, crystallinity, photocatalyst band gap, surface area, and other factors were considered [40,96].
The mechanism of photodegradation is that, when semiconductors (catalysts) consume energy (photons) greater than their bandgap energy, charge separation occurs due to an electron jumping from the valence band to the conduction band of the catalyst, resulting in the creation of a hole in the valence band [64,70,108,122]. The created electron-hole pairs diffuse onto the photocatalyst’s surface and participate in the chemical reaction with the electron donor and acceptor when illuminated by light stronger than the band gap energy. With super strong oxidization, certain free electrons and holes convert the surrounding oxygen or water molecules into highly reactive unstable OH free radicals. When zinc oxide nanoparticles absorb photons with energies greater than their band gap energy from illumination, photocatalytic reactions begin to degrade the dyes [83] (Figure 7). Therefore, among the other zinc species in aqueous dye solutions under the experimental conditions, Zn2+ ions must be the most abundant, followed by Zn(OH)+, Zn(OH)3, and Zn(OH)42–.
In the presence of solar light as a catalyst, the biosynthesized zinc oxide nanoparticles showed a strong degradation capability for Synozol navy blue K-BF, and the hypothesized degradation mechanism yielded the formation of hydroxyl radical and dye degradation into smaller fragments [39]. Alamdari et al. [124] indicated that zinc oxide nanoparticles biosynthesized from the leaf extract of S. ebulus showed the maximum degradation of methylene blue dye noticeably around 80% after 200 min of UV radiation. Recently, Faisal et al. [11] reported that zinc oxide nanoparticles biosynthesized from aqueous fruit extracts of M. fragrans were used as photocatalytic agents, resulting in 88% of methylene blue dye degradation in 140 min of UV light illumination. In addition, Vinayagam et al. [130] reported that zinc oxide nanoparticles synthesized from Bridelia retusa leaf extract promoted the photocatalytic degradation of Rhodamine B dye by up to 94.74% within 165 min of solar irradiation. The crystalline and mesoporous natures, high surface area, and good electron acquiring features of the zinc oxide nanoparticles might be attributed to the accelerated degradation. Furthermore, the improved photocatalytic activity could be attributed to the stabilizing phytocompounds. Likewise, the photocatalytic activity of the plant-mediated zinc oxide nanoparticles is represented in Table 7.

4.8. Wound-Healing Activity

Since our skin is our body’s largest organ, it protects us from external attack, and any damage to it results in a wound. The healing of a wound takes time and can be slowed by microbial infection (P. aeruginosa and S. aureus). Nanoparticles have antibacterial properties and produce hydrogen peroxide, which causes cell damage [87]. Metal oxide nanoparticles can be utilized to destroy the pathogenic species and thereby improve wound healing [67]. Zinc oxide nanoparticles synthesized biologically from plant sources can be tremendously used as a wound-healing agent for treating general wounds and wounds caused due to burning [67,87,114]. Khatami et al. [114] indicated that zinc oxide nanoparticles (about 26 nm in size) synthesized from Prosophis fracta and coffee were found to impregnate on cotton wound bandages, conferring patches with a strong antimicrobial effect. Hence, they can potentially be used for treating and covering infection-sensitive wounds, namely diabetic or burns wounds. Shao et al. [87] biosynthesized zinc oxide nanoparticles from a Barleria gibsoni leaf extract, which acted as efficient and superior tropical antimicrobial formulations for the healing of burn infections by exhibiting a remarkable wound-healing potential in rats. Kiran Kumar et al. [142] studied zinc oxide nanoparticles synthesized from a Raphanus sativus root extract and showed their antimicrobial property against Escherichia fergusonii and E. coli strains that can be further explored for wound-healing potential. Apart from these, many reports have also indicated that the application of zinc oxide nanoparticles/or their biocomposites, irrespective of their application, possessed potential wound-healing ability and help in wound healing [143,144,145,146].

4.9. Targetted Drug Delivery System

Zinc oxide nanoparticles have been considered as a potential candidate for targeted drug delivery because of their ease of synthesis from low-cost metal precursors, biocompatibility, and successful cellular internalization via endocytosis. Nanoparticles’ smaller particle sizes and larger surface areas make it easier for them to penetrate cell membranes and be absorbed into cells, resulting in better distribution. As a result, nanoparticles are commonly used in drug delivery systems, where they are loaded with drugs that reach their targets in appropriate quantities and then guide the drug release from the nanoparticles [51]. The effect of zinc oxide nanoparticles on drug delivery revealed that these nanoparticles aid in the rapid release of the drug at first and then transition to regulate the release over the treatment period [95]. The mechanisms underlying the enhanced cytotoxic potential of anticancer drug-loaded zinc oxide nanoparticles involve the pH-dependent release of targeted drug and zinc oxide nanoparticles in the cytoplasm once the drug-loaded zinc oxide nanoparticles enter through receptor-mediated endocytosis. The release of targeted anticancer drugs act upon cancer cells and cause cell death. Additionally, zinc oxide nanoparticles release Zn2+ ions and produce excessive ROS (oxidative stress) and, subsequently, lead to cancer cell death (Figure 8).
Vimala et al. [52] used green synthesized doxorubicin (DOX)-loaded zinc oxide nanoparticles with Borassus flabellifer fruit extract in a drug delivery system for anticancer therapy. The synthesized DOX–zinc oxide nanoparticles showed dose-dependent cytotoxicity against the human breast cancer MCF-7 and colon cancer HT-29 cell lines, with an inhibitory concentration (IC50) of 0.125 μg·mL−1. Additionally, the toxicity assessment in vivo showed that these DOX–zinc oxide nanoparticles had low systemic toxicity in the murine model system. The low toxicity and high anticancer therapy efficacy of DOX–zinc oxide nanoparticles were found to provide strong evidence for plant-mediated green synthesized zinc oxide nanoparticles as promising candidates in drug delivery systems. Akbarian et al. [95] successfully loaded an important anticancer drug (Paclitaxel, PTX) on chitosan-coated zinc oxide nanoparticles, which were synthesized from the ethanolic leaf extract of Camellia sinensis and evaluated their biological activity as a drug delivery system on breast cancer cell lines (MCF-7). The PTX loaded on the chitosan-coated zinc oxide nanoparticles were found to show acytotoxic (anticancer) effect on cancerous MCF-7 cell lines and reduced the cytotoxic effect on normal fibroblast cell lines. Despite the reports on the use of zinc oxide nanoparticles in targeted drug delivery systems, further research is required to develop zinc oxide nanoparticles synthesized from plant sources as a flexible drug delivery system for targeted delivery. Passive targeting administered nanoparticles preferentially accumulate in solid tumors with discontinuous endothelium based on the enhanced permeability and retention (EPR) phenomenon, which is directly dependent on the size of the particles, which is smaller than the tumor inter-endothelial gap cut-off size. Apart from this, the two fundamental characteristics of neoplastic tissues, such as leaky vasculature and impaired lymphatic drainage, may also facilitate nanoparticle targeting [147].

4.10. Tissue Engineering and Regenerative Medicine

Zinc oxide nanoparticles have emerged as promising materials for tissue engineering and regenerative medicine applications, which can help to promote tissue regeneration while reducing immune responses and preventing infections because of their antineoplastic, angiogenic, ultraviolet scattering, and wound-healing properties [148]. The osteogenesis and angiogenesis effects of zinc oxide nanoparticles have been effectively proven in several investigations due to their extraordinary antibacterial activity, and inexpensive cost [149,150]. Zinc oxide nanoparticles are also found to promote cell growth, proliferation, differentiation, and metabolic activity in a variety of cell lines for tissue engineering and regenerative medicine applications [151]. As a result, the use of plant-mediated zinc oxide nanoparticles in tissue engineering and regenerative medicine has become even more specialized and utilizing the innovative concept that zinc oxide nanoparticles’ proangiogenic properties might be tremendously advantageous in increasing the integration of advanced scaffolds into host tissue, as evidenced by in vitro and in vivo experiments.
Shubha et al. [152] synthesized zinc oxide nanoparticles using Gallic acid isolated from the aqueous extract of Phyllanthus emblica and reported that the smaller-sized plant-mediated zinc oxide nanoparticles were found to cause noticeably lesser toxicity than clinically advocated zinc oxide nanoparticles. Since they employed 3T3 fibroblasts from Balb mice, which are important connective tissue cells that aid in tissue repair and regeneration, and because these zinc oxide nanoparticles are benign to the cells, they can be used close to connective tissue cells. Shafique et al. [153] reported that biosynthesized zinc oxide nanoparticles from a Cymbopogon citratus leaf extract were found, showing a promising callogenesis and regeneration frequency at their optimum concentrations (20 mg·L−1 and 30 mg·L−1 in the internodes and seeds, respectively) in Panicum virgatum, and it was confidently believed that this finding would open new doors in tissue culture technology by increasing the frequency of plant in vitro regeneration in different plant groupings.

5. Future Perspective and Conclusion

Zinc oxide nanoparticles have superior properties in contrast to bulk materials due to their small size and large surface area-to-volume ratio, which makes them explored in various fields, viz., biomedical, biosensor, cosmetic, food industries, etc. Among the different types of zinc oxide nanoparticle synthesis, the nanoparticles synthesized by the green route using plant extract have gained considerable importance in the new millennium due to their eco-friendly, nontoxic, cost-effective nature that can also be reproduced under a large scale. The phytoconstituents/secondary metabolites of plant extracts readily reduce the metal ions and stabilize them into nanoparticles. These phytofabricated zinc oxide nanoparticles offer better antimicrobial, anticancer, anti-inflammatory, and antidiabetic, along with other biomedical, applications due to the coating of various pharmacologically active biomolecules on their surfaces. This review elucidated the eco-friendly nature of green synthesized zinc oxide nanoparticles and their potential application in various biomedical fields, including drug delivery systems, along with their mechanism of action involved at the cellular level. From this review, it may be noted that plant-mediated zinc oxide nanoparticles possess better biological properties that are of human importance and can also be used in drug delivery systems due to their biocompatibility. Inconclusively, this review discussed the possible mechanisms behind plant-mediated green synthesized zinc oxide nanoparticles and advances made towards their role in therapeutic applications in the new millennium.

Author Contributions

Conceptualization, M.M., N.K., M.A. and H.G.G.; methodology, M.A.A., M.N.A., and N.S.; software, S.B.S., S.F.A., M.R.H., and N.A.; validation, M.M., H.G.G., and N.S.; formal analysis, H.G.G., M.N.A., S.A., M.R.H., and S.B.S.; investigation, M.M. and H.G.G.; resources, M.A.A., S.A., S.F.A., and K.N.A.; data curation, M.M., S.A., and H.G.G.; writing—original draft preparation, M.M., N.K., S.B.S., N.S., and M.C.T.; writing—review and editing, M.M., H.G.G., M.A.A., N.A., N.L., and K.N.A.; visualization, M.M. and H.G.G.; supervision, M.A.A. and K.N.A.; project administration, K.N.A.; and funding acquisition, S.F.A. and M.R.H. All authors have read and agreed to the published version of the manuscript.

Funding

The authors would like to acknowledge the Researchers Supporting Project number RSP-2021/222, King Saud University, Riyadh, Saudi Arabia.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available in this manuscript.

Acknowledgments

The authors would like to acknowledge the Researchers Supporting Project number RSP-2021/222, King Saud University, Riyadh, Saudi Arabia. The first author M.M. would like to thank the University Grants Commission (UGC)-New Delhi, India for providing the Post-Doctoral Fellowship for SC/ST Candidates (No. F/PDFSS-2015-17-KAR-11846). The corresponding author K.N. Amruthesh would like to thank Govt. of Karnataka VGST-CISEE Programme on “Herbal Drug Technology” for facilities. The authors thank the Department of Studies in Botany, Department of Studies in Biotechnology, and Department of Studies in Microbiology, University of Mysore, Mysuru for providing facilities to carry out the research.

Conflicts of Interest

The authors declare no competing interests.

References

  1. Anandan, S.; Mahadevamurthy, M.; Ansari, M.A.; Alzohairy, M.A.; Alomary, M.N.; Farha Siraj, S.; Sarjan, H.N.; Mahendra, C.; Lakshmeesha, T.R.; Hemanth Kumar, N.K.; et al. Biosynthesized ZnO-NPs from Morus indica attenuates methylglyoxal-induced protein glycation and RBC damage: In-vitro, in-vivo and molecular docking study. Biomolecules 2019, 9, 882. [Google Scholar] [CrossRef] [Green Version]
  2. Ansari, M.A.; Murali, M.; Prasad, D.; Alzohairy, M.A.; Almatroudi, A.; Alomary, M.N.; Udayashankar, A.C.; Singh, S.B.; Asiri, S.M.M.; Ashwini, B.S.; et al. Cinnamomum verum bark extract mediated green synthesis of ZnO nanoparticles and their antibacterial potentiality. Biomolecules 2020, 10, 336. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  3. Kavya, J.B.; Murali, M.; Manjula, S.; Basavaraj, G.L.; Prathibha, M.; Jayaramu, S.C.; Amruthesh, K.N. Genotoxic and antibacterial nature of biofabricated zinc oxide nanoparticles from Sida rhombifolia Linn. J. Drug Deliv. Sci. Technol. 2020, 60, 101982. [Google Scholar] [CrossRef]
  4. Murali, M.; Anandan, S.; Ansari, M.A.; Alzohairy, M.A.; Alomary, M.N.; Asiri, S.M.M.; Almatroudi, A.; Thrivveni, M.C.; Brijesh Singh, S.; Gowtham, H.G.; et al. Genotoxic and cytotoxic properties of Zinc oxide nanoparticles phyto-fabricated from the Obscure morning glory plant Ipomoea obscura (L.) Ker Gawl. Molecules 2021, 26, 891. [Google Scholar] [CrossRef] [PubMed]
  5. Murali, M.; Mahendra, C.; Nagabhushan; Rajashekar, N.; Sudarshana, M.S.; Raveesha, K.A.; Amruthesh, K.N. Antibacterial and antioxidant properties of biosynthesized zinc oxide nanoparticles from Ceropegia candelabrum L.—An endemic species. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2017, 179, 104–109. [Google Scholar] [CrossRef]
  6. Azizi, S.; Mohamad, R.; Bahadoran, A.; Bayat, S.; Rahim, R.A.; Ariff, A.; Saad, W.Z. Effect of annealing temperature on antimicrobial and structural properties of bio-synthesized zinc oxide nanoparticles using flower extract of Anchusa italic. J. Photochem. Photobiol. B Biol. 2016, 161, 441–449. [Google Scholar] [CrossRef]
  7. Padalia, H.; Chanda, S. Characterization, antifungal and cytotoxic evaluation of green synthesized zinc oxide nanoparticles using Ziziphus nummularia leaf extract. Artif. Cells Nanomed. Biotechnol. 2017, 45, 1751–1761. [Google Scholar] [CrossRef] [Green Version]
  8. Hemanth Kumar, N.K.; Andia, J.D.; Manjunatha, S.; Murali, M.; Amruthesh, K.N.; Jagannath, S. Antimitotic and DNA-binding potential of biosynthesized ZnO-NPs from leaf extract of Justicia wynaadensis (Nees) Heyne—A medicinal herb. Biocatal. Agric. Biotechnol. 2019, 18, 101024. [Google Scholar] [CrossRef]
  9. Prasad, K.S.; Prasad, S.K.; Ansari, M.A.; Alzohairy, M.A.; Alomary, M.N.; AlYahya, S.; Srinivasa, C.; Murali, M.; Ankegowda, V.M.; Shivamallu, C. Tumoricidal and bactericidal properties of ZnONPs synthesized using Cassia auriculata leaf extract. Biomolecules 2020, 10, 982. [Google Scholar] [CrossRef]
  10. Chunchegowda, U.A.; Shivaram, A.B.; Mahadevamurthy, M.; Ramachndrappa, L.T.; Lalitha, S.G.; Krishnappa, H.K.N.; Anandan, S.; Sudarshana, B.S.; Chanappa, E.G.; Ramachandrappa, N.S. Biosynthesis of Zinc oxide nanoparticles using leaf extract of Passiflora subpeltata: Characterization and antibacterial activity against Escherichia coli isolated from poultry faeces. J. Clust. Sci. 2020, 1–10. [Google Scholar] [CrossRef]
  11. Faisal, S.; Jan, H.; Shah, S.A.; Shah, S.; Khan, A.; Akbar, M.T.; Rizwan, M.; Jan, F.; Wajidullah; Akhtar, N.; et al. Green synthesis of Zinc oxide (ZnO) nanoparticles using aqueous fruit extracts of Myristica fragrans: Their characterizations and biological and environmental applications. ACS Omega 2021, 6, 9709–9722. [Google Scholar] [CrossRef]
  12. Stan, M.; Popa, A.; Toloman, D.; Silipas, T.D.; Vodnar, D.C. Antibacterial and antioxidant activities of ZnO nanoparticles synthesized using extracts of Allium sativum, Rosmarinus officinalis and Ocimum basilicum. Acta Metall. Sin. 2016, 29, 228–236. [Google Scholar] [CrossRef] [Green Version]
  13. Elumalai, K.; Velmurugan, S. Green synthesis, characterization and antimicrobial activities of zinc oxide nanoparticles from the leaf extract of Azadirachta indica (L.). Appl. Surf. Sci. 2015, 345, 329–336. [Google Scholar] [CrossRef]
  14. Hemanth Kumar, N.K.; Murali, M.; Satish, A.; Singh, S.B.; Gowtham, H.G.; Mahesh, H.M.; Lakshmeesha, T.R.; Amruthesh, K.N.; Jagannath, S. Bioactive and biocompatible nature of green synthesized zinc oxide nanoparticles from Simarouba glauca DC.: An endemic plant to Western Ghats, India. J. Clust. Sci. 2020, 31, 523–534. [Google Scholar] [CrossRef]
  15. Dobrucka, R.; Długaszewska, J. Biosynthesis and antibacterial activity of ZnO nanoparticles using Trifolium pratense flower extract. Saudi J. Biol. Sci. 2016, 23, 517–523. [Google Scholar] [CrossRef] [Green Version]
  16. Thatoi, P.; Kerry, R.G.; Gouda, S.; Das, G.; Pramanik, K.; Thatoi, H.; Patra, J.K. Photo-mediated green synthesis of silver and zinc oxide nanoparticles using aqueous extracts of two mangrove plant species, Heritiera fomes and Sonneratia apetala and investigation of their biomedical applications. J. Photochem. Photobiol. B Biol. 2016, 163, 311–318. [Google Scholar] [CrossRef]
  17. Nagajyothi, P.C.; Cha, S.J.; Yang, I.J.; Sreekanth, T.V.M.; Kim, K.J.; Shin, H.M. Antioxidant and anti-inflammatory activities of zinc oxide nanoparticles synthesized using Polygala tenuifolia root extract. J. Photochem. Photobiol. B Biol. 2015, 146, 10–17. [Google Scholar] [CrossRef]
  18. Wang, Z.L. Nanostructures of Zinc oxide. Mater. Today 2004, 7, 26–33. [Google Scholar] [CrossRef]
  19. Gao, Y.; Xu, D.; Ren, D.; Zeng, K.; Wu, X. Green synthesis of zinc oxide nanoparticles using Citrus sinensis peel extract and application to strawberry preservation: A comparison study. LWT 2020, 126, 109297. [Google Scholar] [CrossRef]
  20. Ali, S.G.; Ansari, M.A.; Jamal, Q.M.S.; Almatroudi, A.; Alzohairy, M.A.; Alomary, M.N.; Rehman, S.; Murali, M.; Jalal, M.; Khan, M.H.; et al. Butea monosperma seed extract mediated biosynthesis of ZnO NPs and their antibacterial, antibiofilm and anti-quorum sensing potentialities. Arab. J. Chem. 2021, 14, 103044. [Google Scholar] [CrossRef]
  21. Agarwal, H.; Shanmugam, V.K. Synthesis and optimization of zinc oxide nanoparticles using Kalanchoe pinnata towards the evaluation of its anti-inflammatory activity. J. Drug Deliv. Sci. Technol. 2019, 54, 101291. [Google Scholar] [CrossRef]
  22. Rehana, D.; Mahendiran, D.; Kumar, R.S.; Rahiman, A.K. In vitro antioxidant and antidiabetic activities of zinc oxide nanoparticles synthesized using different plant extracts. Bioprocess Biosyst. Eng. 2017, 40, 943–957. [Google Scholar] [CrossRef]
  23. Sanaeimehr, Z.; Javadi, I.; Namvar, F. Antiangiogenic and antiapoptotic effects of green-synthesized zinc oxide nanoparticles using Sargassum muticum algae extraction. Cancer Nanotechnol. 2018, 9, 1–16. [Google Scholar] [CrossRef]
  24. Yusof, H.M.; Mohamad, R.; Zaidan, U.H. Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: A review. J. Anim. Sci. Biotechnol. 2019, 10, 1–22. [Google Scholar]
  25. Pillai, A.M.; Sivasankarapillai, V.S.; Rahdar, A.; Joseph, J.; Sadeghfar, F.; Ronaldo Anuf, A.; Rajesh, K.; Kyzas, G.Z. Green synthesis and characterization of zinc oxide nanoparticles with antibacterial and antifungal activity. J. Mol. Struct. 2020, 1211, 128107. [Google Scholar] [CrossRef]
  26. Umar, H.; Kavaz, D.; Rizaner, N. Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines. Int. J. Nanomedicine 2019, 14, 87–100. [Google Scholar] [CrossRef] [Green Version]
  27. Agarwal, H.; Menon, S.; Shanmugam, V.K. Functionalization of zinc oxide nanoparticles using Mucuna pruriens and its antibacterial activity. Surf. Interfaces 2020, 19, 100521. [Google Scholar] [CrossRef]
  28. Mahendra, C.; Chandra, M.N.; Murali, M.; Abhilash, M.R.; Singh, S.B.; Satish, S.; Sudarshana, M.S. Phyto-fabricated ZnO nanoparticles from Canthium dicoccum (L.) for Antimicrobial, Anti-tuberculosis and Antioxidant activity. Process Biochem. 2020, 89, 220–226. [Google Scholar] [CrossRef]
  29. Umamaheswari, A.; Prabu, S.L.; John, S.A.; Puratchikody, A. Green synthesis of zinc oxide nanoparticles using leaf extracts of Raphanus sativus var. longipinnatus and evaluation of their anticancer property in A549 cell lines. Biotechnol. Rep. 2021, 29, e00595. [Google Scholar] [CrossRef]
  30. Sharmila, G.; Muthukumaran, C.; Sandiya, K.; Santhiya, S.; Pradeep, R.S.; Kumar, N.M.; Suriyanarayanan, N.; Thirumarimurugan, M. Biosynthesis, characterization, and antibacterial activity of zinc oxide nanoparticles derived from Bauhinia tomentosa leaf extract. J. Nanostruct. Chem. 2018, 8, 293–299. [Google Scholar] [CrossRef] [Green Version]
  31. Quek, J.A.; Sin, J.C.; Lam, S.M.; Mohamed, A.R.; Zeng, H.H. Bioinspired green synthesis of ZnO structures with enhanced visible light photocatalytic activity. J. Mater. Sci. Mater. Electron. 2020, 31, 1144–1158. [Google Scholar] [CrossRef]
  32. Jamdagni, P.; Khatri, P.; Rana, J.S. Green synthesis of zinc oxide nanoparticles using flower extract of Nyctanthes arbor-tristis and their antifungal activity. J. King Saud Univ. Sci. 2018, 30, 168–175. [Google Scholar] [CrossRef] [Green Version]
  33. Vinotha, V.; Iswarya, A.; Thaya, R.; Govindarajan, M.; Alharbi, N.S.; Kadaikunnan, S.; Khaled, J.M.; Al-Anbr, M.N.; Vaseeharan, B. Synthesis of ZnO nanoparticles using insulin-rich leaf extract: Anti-diabetic, antibiofilm and anti-oxidant properties. J. Photochem. Photobiol. B Biol. 2019, 197, 111541. [Google Scholar] [CrossRef] [PubMed]
  34. Rajakumar, G.; Thiruvengadam, M.; Mydhili, G.; Gomathi, T.; Chung, I.M. Green approach for synthesis of zinc oxide nanoparticles from Andrographis paniculata leaf extract and evaluation of their antioxidant, anti-diabetic, and anti-inflammatory activities. Bioprocess Biosyst. Eng. 2018, 41, 21–30. [Google Scholar] [CrossRef]
  35. Bala, N.; Saha, S.; Chakraborty, M.; Maiti, M.; Das, S.; Basu, R.; Nandy, P. Green synthesis of zinc oxide nanoparticles using Hibiscus subdariffa leaf extract: Effect of temperature on synthesis, anti-bacterial activity and anti-diabetic activity. RSC Adv. 2015, 5, 4993–5003. [Google Scholar] [CrossRef]
  36. Madan, H.R.; Sharma, S.C.; Udayabhanu; Suresh, D.; Vidya, Y.S.; Nagabhushana, H.; Rajanaik, H.; Anantharaju, K.S.; Prashantha, S.C.; Sadananda Maiya, P. Facile green fabrication of nanostructure ZnO plates, bullets, flower, prismatic tip, closed pine cone: Their antibacterial, antioxidant, photoluminescent and photocatalytic properties. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2016, 152, 404–416. [Google Scholar] [CrossRef]
  37. Kołodziejczak-Radzimska, A.; Jesionowski, T. Zinc oxide—From synthesis to application: A review. Materials 2014, 7, 2833–2881. [Google Scholar] [CrossRef] [Green Version]
  38. Roopan, S.M.; Mathew, R.S.; Mahesh, S.S.; Titus, D.; Aggarwal, K.; Bhatia, N.; Damodharan, K.I.; Elumalai, K.; Samuel, J.J. Environmental friendly synthesis of zinc oxide nanoparticles and estimation of its larvicidal activity against Aedes aegypti. Int. J. Environ. Sci. Technol. 2019, 16, 8053–8060. [Google Scholar] [CrossRef]
  39. Khan, Z.U.H.; Sadiq, H.M.; Shah, N.S.; Khan, A.U.; Muhammad, N.; Hassan, S.U.; Tahir, K.; Safi, S.Z.; Khan, F.U.; Imran, M.; et al. Greener synthesis of zinc oxide nanoparticles using Trianthema portulacastrum extract and evaluation of its photocatalytic and biological applications. J. Photochem. Photobiol. B Biol. 2019, 192, 147–157. [Google Scholar] [CrossRef]
  40. Abdullah, F.H.; Abu Bakar, N.H.H.; Abu Bakar, M. Low temperature biosynthesis of crystalline zinc oxide nanoparticles from Musa acuminata peel extract for visible-light degradation of methylene blue. Optik 2020, 206, 164279. [Google Scholar] [CrossRef]
  41. Iravani, S. Green synthesis of metal nanoparticles using plants. Green Chem. 2011, 13, 2638–2650. [Google Scholar] [CrossRef]
  42. El Shafey, A.M. Green synthesis of metal and metal oxide nanoparticles from plant leaf extracts and their applications: A review. Green Process. Synth. 2020, 9, 304–339. [Google Scholar] [CrossRef]
  43. Singh, S.C.; Gopal, R. Drop shaped zinc oxide quantum dots and their self-assembly into dendritic nanostructures: Liquid assisted pulsed laser ablation and characterizations. Appl. Surf. Sci. 2012, 258, 2211–2218. [Google Scholar] [CrossRef]
  44. Gunalan, S.; Sivaraj, R.; Rajendran, V. Green synthesized ZnO nanoparticles against bacterial and fungal pathogens. Prog. Nat. Sci. Mater. Int. 2012, 22, 693–700. [Google Scholar] [CrossRef] [Green Version]
  45. Agarwal, H.; Menon, S.; Kumar, S.V.; Rajeshkumar, S. Mechanistic study on antibacterial action of zinc oxide nanoparticles synthesized using green route. Chem. Biol. Interact. 2018, 286, 60–70. [Google Scholar] [CrossRef]
  46. Das, D.; Nath, B.C.; Phukon, P.; Kalita, A.; Dolui, S.K. Synthesis of ZnO nanoparticles and evaluation of antioxidant and cytotoxic activity. Colloids Surf. B Biointerfaces 2013, 111, 556–560. [Google Scholar] [CrossRef]
  47. Nithya, K.; Kalyanasundharam, S. Effect of chemically synthesis compared to biosynthesized ZnO nanoparticles using aqueous extract of C. halicacabum and their antibacterial activity. OpenNano 2019, 4, 100024. [Google Scholar] [CrossRef]
  48. Happy, A.; Soumya, M.; Venkat Kumar, S.; Rajeshkumar, S.; Sheba, R.D.; Lakshmi, T.; Nallaswamy, V.D. Phyto-assisted synthesis of zinc oxide nanoparticles using Cassia alata and its antibacterial activity against Escherichia coli. Biochem. Biophys. Rep. 2019, 17, 208–211. [Google Scholar] [CrossRef]
  49. Marslin, G.; Siram, K.; Maqbool, Q.; Selvakesavan, R.K.; Kruszka, D.; Kachlicki, P.; Franklin, G. Secondary metabolites in the green synthesis of metallic nanoparticles. Materials 2018, 11, 940. [Google Scholar] [CrossRef] [Green Version]
  50. Basnet, P.; Chanu, T.I.; Samanta, D.; Chatterjee, S. A review on bio-synthesized zinc oxide nanoparticles using plant extracts as reductants and stabilizing agents. J. Photochem. Photobiol. B Biol. 2018, 183, 201–221. [Google Scholar] [CrossRef]
  51. Ramesh, M.; Anbuvannan, M.; Viruthagiri, G. Green synthesis of ZnO nanoparticles using Solanum nigrum leaf extract and their antibacterial activity. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2015, 136, 864–870. [Google Scholar] [CrossRef] [PubMed]
  52. Vimala, K.; Sundarraj, S.; Paulpandi, M.; Vengatesan, S.; Kannan, S. Green synthesized doxorubicin loaded zinc oxide nanoparticles regulates the Bax and Bcl-2 expression in breast and colon carcinoma. Process Biochem. 2014, 49, 160–172. [Google Scholar] [CrossRef]
  53. Anbuvannan, M.; Ramesh, M.; Viruthagiri, G.; Shanmugam, N.; Kannadasan, N. Synthesis, characterization and photocatalytic activity of ZnO nanoparticles prepared by biological method. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2015, 143, 304–308. [Google Scholar] [CrossRef]
  54. Anbuvannan, M.; Ramesh, M.; Viruthagiri, G.; Shanmugam, N.; Kannadasan, N. Anisochilus carnosus leaf extract mediated synthesis of zinc oxide nanoparticles for antibacterial and photocatalytic activities. Mater. Sci. Semicond. Process. 2015, 39, 621–628. [Google Scholar] [CrossRef]
  55. Vijayakumar, S.; Vinoj, G.; Malaikozhundan, B.; Shanthi, S.; Vaseeharan, B. Plectranthus amboinicus leaf extract mediated synthesis of zinc oxide nanoparticles and its control of methicillin resistant Staphylococcus aureus biofilm and blood sucking mosquito larvae. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2015, 137, 886–891. [Google Scholar] [CrossRef] [PubMed]
  56. Fowsiya, J.; Madhumitha, G.; Al-Dhabi, N.A.; Arasu, M.V. Photocatalytic degradation of Congo red using Carissa edulis extract capped zinc oxide nanoparticles. J. Photochem. Photobiol. B Biol. 2016, 162, 395–401. [Google Scholar] [CrossRef]
  57. Jafarirad, S.; Mehrabi, M.; Divband, B.; Kosari-Nasab, M. Biofabrication of zinc oxide nanoparticles using fruit extract of Rosa canina and their toxic potential against bacteria: A mechanistic approach. Mater. Sci. Eng. C 2016, 59, 296–302. [Google Scholar] [CrossRef]
  58. Karnan, T.; Selvakumar, S.A.S. Biosynthesis of ZnO nanoparticles using rambutan (Nephelium lappaceum L.) peel extract and their photocatalytic activity on methyl orange dye. J. Mol. Struct. 2016, 1125, 358–365. [Google Scholar] [CrossRef]
  59. Patil, B.N.; Taranath, T.C. Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis. Int. J. Mycobacteriol. 2016, 5, 197–204. [Google Scholar] [CrossRef] [Green Version]
  60. Sharma, S.C. ZnO nano-flowers from Carica papaya milk: Degradation of Alizarin Red-S dye and antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus. Optik 2016, 127, 6498–6512. [Google Scholar] [CrossRef]
  61. Supraja, N.; Prasad, T.N.V.K.V.; Krishna, T.G.; David, E. Synthesis, characterization, and evaluation of the antimicrobial efficacy of Boswellia ovalifoliolata stem bark-extract-mediated zinc oxide nanoparticles. Appl. Nanosci. 2016, 6, 581–590. [Google Scholar] [CrossRef] [Green Version]
  62. Nava, O.J.; Luque, P.A.; Gómez-Gutiérrez, C.M.; Vilchis-Nestor, A.R.; Castro-Beltrán, A.; Mota-González, M.L.; Olivas, A. Influence of Camellia sinensis extract on Zinc oxide nanoparticle green synthesis. J. Mol. Struct. 2017, 1134, 121–125. [Google Scholar] [CrossRef]
  63. Bayrami, A.; Parvinroo, S.; Habibi-Yangjeh, A.; Pouran, S.R. Bio-extract-mediated ZnO nanoparticles: Microwave-assisted synthesis, characterization and antidiabetic activity evaluation. Artif. Cells Nanomed. Biotechnol. 2018, 46, 730–739. [Google Scholar] [CrossRef]
  64. Luque, P.A.; Soto-Robles, C.A.; Nava, O.; Gomez-Gutierrez, C.M.; Castro-Beltran, A.; Garrafa-Galvez, H.E.; Vilchis-Nestor, A.R.; Olivas, A. Green synthesis of zinc oxide nanoparticles using Citrus sinensis extract. J. Mater. Sci. Mater. Electron. 2018, 29, 9764–9770. [Google Scholar] [CrossRef]
  65. Rajeshkumar, S.; Kumar, S.V.; Ramaiah, A.; Agarwal, H.; Lakshmi, T.; Roopan, S.M. Biosynthesis of zinc oxide nanoparticles using Mangifera indica leaves and evaluation of their antioxidant and cytotoxic properties in lung cancer (A549) cells. Enzyme Microb. Technol. 2018, 117, 91–95. [Google Scholar] [CrossRef]
  66. Suresh, J.; Pradheesh, G.; Alexramani, V.; Sundrarajan, M.; Hong, S.I. Green synthesis and characterization of zinc oxide nanoparticle using insulin plant (Costus pictus D. Don) and investigation of its antimicrobial as well as anticancer activities. Adv. Nat. Sci. Nanosci. Nanotechnol. 2018, 9, 015008. [Google Scholar] [CrossRef]
  67. Ezealisiji, K.M.; Siwe-Noundou, X.; Maduelosi, B.; Nwachukwu, N.; Krause, R.W.M. Green synthesis of zinc oxide nanoparticles using Solanum torvum (L) leaf extract and evaluation of the toxicological profile of the ZnO nanoparticles–hydrogel composite in Wistar albino rats. Int. Nano Lett. 2019, 9, 99–107. [Google Scholar] [CrossRef] [Green Version]
  68. Shanavas, S.; Duraimurugan, J.; Kumar, G.S.; Ramesh, R.; Acevedo, R.; Anbarasan, P.M.; Maadeswaran, P. Ecofriendly green synthesis of ZnO nanostructures using Artabotrys hexapetalu and Bambusa vulgaris plant extract and investigation on their photocatalytic and antibacterial activity. Mater. Res. Express 2019, 6, 105098. [Google Scholar] [CrossRef]
  69. Ruddaraju, L.K.; Pammi, S.V.N.; Pallela, P.N.V.K.; Padavala, V.S.; Kolapalli, V.R.M. Antibiotic potentiation and anti-cancer competence through bio-mediated ZnO nanoparticles. Mater. Sci. Eng. C 2019, 103, 109756. [Google Scholar] [CrossRef]
  70. Tettey, C.O.; Shin, H.M. Evaluation of the antioxidant and cytotoxic activities of zinc oxide nanoparticles synthesized using Scutellaria baicalensis root. Sci. Afr. 2019, 6, e00157. [Google Scholar] [CrossRef]
  71. Sana, S.S.; Kumbhakar, D.V.; Pasha, A.; Pawar, S.C.; Grace, A.N.; Singh, R.P.; Nguyen, V.H.; Le, Q.V.; Peng, W. Crotalaria verrucosa leaf extract mediated synthesis of Zinc oxide nanoparticles: Assessment of antimicrobial and anticancer activity. Molecules 2020, 25, 4896. [Google Scholar] [CrossRef]
  72. Elumalai, K.; Velmurugan, S.; Ravi, S.; Kathiravan, V.; Adaikala Raj, G. Bio-approach: Plant mediated synthesis of ZnO nanoparticles and their catalytic reduction of methylene blue and antimicrobial activity. Adv. Powder Technol. 2015, 26, 1639–1651. [Google Scholar] [CrossRef]
  73. Fu, L.; Fu, Z. Plectranthus amboinicus leaf extract–assisted biosynthesis of ZnO nanoparticles and their photocatalytic activity. Ceram. Int. 2015, 41, 2492–2496. [Google Scholar] [CrossRef]
  74. Stan, M.; Popa, A.; Toloman, D.; Dehelean, A.; Lung, I.; Katona, G. Enhanced photocatalytic degradation properties of zinc oxide nanoparticles synthesized by using plant extracts. Mater. Sci. Semicond. Process. 2015, 39, 23–29. [Google Scholar] [CrossRef]
  75. Sundrarajan, M.; Ambika, S.; Bharathi, K. Plant-extract mediated synthesis of ZnO nanoparticles using Pongamia pinnata and their activity against pathogenic bacteria. Adv. Powder Technol. 2015, 26, 1294–1299. [Google Scholar] [CrossRef]
  76. Suresh, D.; Nethravathi, P.C.; Udayabhanu; Rajanaika, H.; Nagabhushana, H.; Sharma, S.C. Green synthesis of multifunctional zinc oxide (ZnO) nanoparticles using Cassia fistula plant extract and their photodegradative, antioxidant and antibacterial activities. Mater. Sci. Semicond. Process. 2015, 31, 446–454. [Google Scholar] [CrossRef]
  77. Suresh, D.; Shobharani, R.M.; Nethravathi, P.C.; Pavan Kumar, M.A.; Nagabhushana, H.; Sharma, S.C. Artocarpus gomezianus aided green synthesis of ZnO nanoparticles: Luminescence, photocatalytic and antioxidant properties. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2015, 141, 128–134. [Google Scholar] [CrossRef]
  78. Zheng, Y.; Fu, L.; Han, F.; Wang, A.; Cai, W.; Yu, J.; Yang, J.; Peng, F. Green biosynthesis and characterization of zinc oxide nanoparticles using Corymbia citriodora leaf extract and their photocatalytic activity. Green Chem. Lett. Rev. 2015, 8, 59–63. [Google Scholar] [CrossRef]
  79. Rana, N.; Chand, S.; Gathania, A.K. Green synthesis of zinc oxide nano-sized spherical particles using Terminalia chebula fruits extract for their photocatalytic applications. Int. Nano Lett. 2016, 6, 91–98. [Google Scholar] [CrossRef] [Green Version]
  80. Azizi, S.; Mohamad, R.; Shahri, M.M. Green microwave-assisted combustion synthesis of Zinc oxide nanoparticles with Citrullus colocynthis (L.) Schrad: Characterization and biomedical applications. Molecules 2017, 22, 301. [Google Scholar] [CrossRef] [Green Version]
  81. Dayakar, T.; Venkateswara Rao, K.; Bikshalu, K.; Rajendar, V.; Park, S.H. Novel synthesis and structural analysis of zinc oxide nanoparticles for the non enzymatic glucose biosensor. Mater. Sci. Eng. C 2017, 75, 1472–1479. [Google Scholar] [CrossRef] [PubMed]
  82. Mahendra, C.; Murali, M.; Manasa, G.; Ponnamma, P.; Abhilash, M.R.; Lakshmeesha, T.R.; Satish, A.; Amruthesh, K.N.; Sudarshana, M.S. Antibacterial and antimitotic potential of bio-fabricated zinc oxide nanoparticles of Cochlospermum religiosum (L.). Microb. Pathog. 2017, 110, 620–629. [Google Scholar] [CrossRef] [PubMed]
  83. Siripireddy, B.; Mandal, B.K. Facile green synthesis of zinc oxide nanoparticles by Eucalyptus globulus and their photocatalytic and antioxidant activity. Adv. Powder Technol. 2017, 28, 785–797. [Google Scholar] [CrossRef]
  84. Taghavi Fardood, S.; Ramazani, A.; Moradi, S.; Azimzadeh Asiabi, P. Green synthesis of zinc oxide nanoparticles using arabic gum and photocatalytic degradation of direct blue 129 dye under visible light. J. Mater. Sci. Mater. Electron. 2017, 28, 13596–13601. [Google Scholar] [CrossRef]
  85. Ali, J.; Irshad, R.; Li, B.; Tahir, K.; Ahmad, A.; Shakeel, M.; Khan, N.U.; Khan, Z.U.H. Synthesis and characterization of phytochemical fabricated zinc oxide nanoparticles with enhanced antibacterial and catalytic applications. J. Photochem. Photobiol. B Biol. 2018, 183, 349–356. [Google Scholar] [CrossRef]
  86. Aminuzzaman, M.; Ying, L.P.; Goh, W.S.; Watanabe, A. Green synthesis of zinc oxide nanoparticles using aqueous extract of Garcinia mangostana fruit pericarp and their photocatalytic activity. Bull. Mater. Sci. 2018, 41, 50. [Google Scholar] [CrossRef] [Green Version]
  87. Shao, F.; Yang, A.; Yu, D.M.; Wang, J.; Gong, X.; Tian, H.X. Bio-synthesis of Barleria gibsoni leaf extract mediated zinc oxide nanoparticles and their formulation gel for wound therapy in nursing care of infants and children. J. Photochem. Photobiol. B Biol. 2018, 189, 267–273. [Google Scholar] [CrossRef]
  88. Zhao, C.; Zhang, X.; Zheng, Y. Biosynthesis of polyphenols functionalized ZnO nanoparticles: Characterization and their effect on human pancreatic cancer cell line. J. Photochem. Photobiol. B Biol. 2018, 183, 142–146. [Google Scholar] [CrossRef]
  89. Asik, R.M.; Gowdhami, B.; Jaabir, M.S.M.; Archunan, G.; Suganthy, N. Anticancer potential of zinc oxide nanoparticles against cervical carcinoma cells synthesized via biogenic route using aqueous extract of Gracilaria edulis. Mater. Sci. Eng. C 2019, 103, 109840. [Google Scholar] [CrossRef]
  90. Hafeez, M.; Arshad, R.; Hameed, M.U.; Akram, B.; Ahmed, M.N.; Kazmi, S.A.; Ahmad, I.; Ali, S. Populus ciliata leaves extract mediated synthesis of zinc oxide nanoparticles and investigation of their anti-bacterial activities. Mater. Res. Express 2019, 6, 075064. [Google Scholar] [CrossRef]
  91. Rad, S.S.; Sani, A.M.; Mohseni, S. Biosynthesis, characterization and antimicrobial activities of zinc oxide nanoparticles from leaf extract of Mentha pulegium (L.). Microb. Pathog. 2019, 131, 239–245. [Google Scholar] [CrossRef] [PubMed]
  92. Chemingui, H.; Missaoui, T.; Mzali, J.C.; Yildiz, T.; Konyar, M.; Smiri, M.; Saidi, N.; Hafiane, A.; Yatmaz, H.C. Facile green synthesis of zinc oxide nanoparticles (ZnO NPs): Antibacterial and photocatalytic activities. Mater. Res. Express 2019, 6, 1050b4. [Google Scholar] [CrossRef]
  93. Majeed, S.; Danish, M.; Ismail, M.H.B.; Ansari, M.T.; Ibrahim, M.N.M. Anticancer and apoptotic activity of biologically synthesized zinc oxide nanoparticles against human colon cancer HCT-116 cell line- in vitro study. Sustain. Chem. Pharm. 2019, 14, 100179. [Google Scholar] [CrossRef]
  94. Ahmad, H.; Venugopal, K.; Rajagopal, K.; De Britto, S.; Nandini, B.; Pushpalatha, H.G.; Konappa, N.; Udayashankar, A.C.; Geetha, N.; Jogaiah, S. Green synthesis and characterization of Zinc oxide nanoparticles using Eucalyptus globules and their fungicidal ability against pathogenic fungi of Apple orchards. Biomolecules 2020, 10, 425. [Google Scholar] [CrossRef] [Green Version]
  95. Akbarian, M.; Mahjoub, S.; Elahi, S.M.; Zabihi, E.; Tashakkorian, H. Green synthesis, formulation and biological evaluation of a novel ZnO nanocarrier loaded with paclitaxel as drug delivery system on MCF-7 cell line. Colloids Surf. B Biointerfaces 2020, 186, 110686. [Google Scholar] [CrossRef]
  96. Golmohammadi, M.; Honarmand, M.; Ghanbari, S. A green approach to synthesis of ZnO nanoparticles using jujube fruit extract and their application in photocatalytic degradation of organic dyes. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2020, 229, 117961. [Google Scholar] [CrossRef]
  97. Jayappa, M.D.; Ramaiah, C.K.; Kumar, M.A.P.; Suresh, D.; Prabhu, A.; Devasya, R.P.; Sheikh, S. Green synthesis of zinc oxide nanoparticles from the leaf, stem and in vitro grown callus of Mussaenda frondosa L.: Characterization and their applications. Appl. Nanosci. 2020, 10, 3057–3074. [Google Scholar] [CrossRef]
  98. Mallikarjunaswamy, C.; Lakshmi Ranganatha, V.; Ramu, R.; Udayabhanu; Nagaraju, G. Facile microwave-assisted green synthesis of ZnO nanoparticles: Application to photodegradation, antibacterial and antioxidant. J. Mater. Sci. Mater. Electron. 2020, 31, 1004–1021. [Google Scholar] [CrossRef]
  99. Selim, Y.A.; Azb, M.A.; Ragab, I.; Abd El-Azim, M.H.M. Green synthesis of Zinc oxide nanoparticles using aqueous extract of Deverra tortuosa and their cytotoxic activities. Sci. Rep. 2020, 10, 3445. [Google Scholar] [CrossRef] [Green Version]
  100. Santhoshkumar, J.; Kumar, S.V.; Rajeshkumar, S. Synthesis of zinc oxide nanoparticles using plant leaf extract against urinary tract infection pathogen. Resour. Technol. 2017, 3, 459–465. [Google Scholar] [CrossRef]
  101. Mahdizadeh, R.; Homayouni-Tabrizi, M.; Neamati, A.; Seyedi, S.M.R.; Tavakkol Afshari, H.S. Green synthesized-zinc oxide nanoparticles, the strong apoptosis inducer as an exclusive antitumor agent in murine breast tumor model and human breast cancer cell lines (MCF7). J. Cell. Biochem. 2019, 120, 17984–17993. [Google Scholar] [CrossRef]
  102. Mohammad, R.K.S.G.; Homayouni Tabrizi, M.; Ardalan, T.; Yadamani, S.; Safavi, E. Green synthesis of zinc oxide nanoparticles and evaluation of anti-angiogenesis, anti-inflammatory and cytotoxicity properties. J. Biosci. 2019, 44, 30. [Google Scholar] [CrossRef]
  103. Vijayakumar, S.; Mahadevan, S.; Arulmozhi, P.; Sriram, S.; Praseetha, P.K. Green synthesis of zinc oxide nanoparticles using Atalantia monophylla leaf extracts: Characterization and antimicrobial analysis. Mater. Sci. Semicond. Process. 2018, 82, 39–45. [Google Scholar] [CrossRef]
  104. Cheng, J.; Wang, X.; Qiu, L.; Li, Y.; Marraiki, N.; Elgorban, A.M.; Xue, L. Green synthesized zinc oxide nanoparticles regulates the apoptotic expression in bone cancer cells MG-63 cells. J. Photochem. Photobiol. B Biol. 2020, 202, 111644. [Google Scholar] [CrossRef]
  105. Jevapatarakul, D.; T-Thienprasert, J.; Payungporn, S.; Chavalit, T.; Khamwut, A.; T-Thienprasert, N.P. Utilization of Cratoxylum formosum crude extract for synthesis of ZnO nanosheets: Characterization, biological activities and effects on gene expression of nonmelanoma skin cancer cell. Biomed. Pharmacother. 2020, 130, 110552. [Google Scholar] [CrossRef]
  106. Rafique, M.; Tahir, R.; Gillani, S.S.A.; Tahir, M.B.; Shakil, M.; Iqbal, T.; Abdellahi, M.O. Plant-mediated green synthesis of zinc oxide nanoparticles from Syzygium cumini for seed germination and wastewater purification. Int. J. Environ. Anal. Chem. 2020, 1–16. [Google Scholar] [CrossRef]
  107. Rahimi Kalateh Shah Mohammad, G.; Karimi, E.; Oskoueian, E.; Homayouni-Tabrizi, M. Anticancer properties of green-synthesised zinc oxide nanoparticles using Hyssopus officinalis extract on prostate carcinoma cells and its effects on testicular damage and spermatogenesis in Balb/C mice. Andrologia 2020, 52, e13450. [Google Scholar] [CrossRef]
  108. Ullah, S.; Ahmad, A.; Ri, H.; Khan, A.U.; Khan, U.A.; Yuan, Q. Green synthesis of catalytic Zinc oxide nano-flowers and their bacterial infection therapy. Appl. Organomet. Chem. 2020, 34, e5298. [Google Scholar] [CrossRef]
  109. Banumathi, B.; Malaikozhundan, B.; Vaseeharan, B. In vitro acaricidal activity of ethnoveterinary plants and green synthesis of zinc oxide nanoparticles against Rhipicephalus (Boophilus) microplus. Vet. Parasitol. 2016, 216, 93–100. [Google Scholar] [CrossRef]
  110. Fatimah, I.; Pradita, R.Y.; Nurfalinda, A. Plant extract mediated of ZnO nanoparticles by using ethanol extract of Mimosa pudica leaves and Coffee powder. Procedia Eng. 2016, 148, 43–48. [Google Scholar] [CrossRef] [Green Version]
  111. Malaikozhundan, B.; Vaseeharan, B.; Vijayakumar, S.; Pandiselvi, K.; Kalanjiam, M.A.R.; Murugan, K.; Benelli, G. Biological therapeutics of Pongamia pinnata coated zinc oxide nanoparticles against clinically important pathogenic bacteria, fungi and MCF-7 breast cancer cells. Microb. Pathog. 2017, 104, 268–277. [Google Scholar] [CrossRef]
  112. Sathishkumar, G.; Rajkuberan, C.; Manikandan, K.; Prabukumar, S.; DanielJohn, J.; Sivaramakrishnan, S. Facile biosynthesis of antimicrobial zinc oxide (ZnO) nanoflakes using leaf extract of Couroupita guianensis Aubl. Mater. Lett. 2017, 188, 383–386. [Google Scholar] [CrossRef]
  113. Gupta, M.; Tomar, R.S.; Kaushik, S.; Mishra, R.K.; Sharma, D. Effective antimicrobial activity of green ZnO nano particles of Catharanthus roseus. Front. Microbiol. 2018, 9, 2030. [Google Scholar] [CrossRef]
  114. Khatami, M.; Varma, R.S.; Zafarnia, N.; Yaghoobi, H.; Sarani, M.; Kumar, V.G. Applications of green synthesized Ag, ZnO and Ag/ZnO nanoparticles for making clinical antimicrobial wound-healing bandages. Sustain. Chem. Pharm. 2018, 10, 9–15. [Google Scholar] [CrossRef]
  115. Mehr, E.S.; Sorbiun, M.; Ramazani, A.; Fardood, S.T. Plant-mediated synthesis of zinc oxide and copper oxide nanoparticles by using Ferulago angulata (schlecht) boiss extract and comparison of their photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. J. Mater. Sci. Mater. Electron. 2018, 29, 1333–1340. [Google Scholar] [CrossRef]
  116. Ramanarayanan, R.; Bhabhina, N.M.; Dharsana, M.V.; Nivedita, C.V.; Sindhu, S. Green synthesis of zinc oxide nanoparticles using extract of Averrhoa bilimbi (L) and their photoelectrode applications. Mater. Today Proc. 2018, 5, 16472–16477. [Google Scholar] [CrossRef]
  117. Safawo, T.; Sandeep, B.V.; Pola, S.; Tadesse, A. Synthesis and characterization of zinc oxide nanoparticles using tuber extract of anchote (Coccinia abyssinica (Lam.) Cong.) for antimicrobial and antioxidant activity assessment. OpenNano 2018, 3, 56–63. [Google Scholar] [CrossRef]
  118. Chandra, H.; Patel, D.; Kumari, P.; Jangwan, J.S.; Yadav, S. Phyto-mediated synthesis of zinc oxide nanoparticles of Berberisaristata: Characterization, antioxidant activity and antibacterial activity with special reference to urinary tract pathogens. Mater. Sci. Eng. C 2019, 102, 212–220. [Google Scholar] [CrossRef] [PubMed]
  119. Darvishi, E.; Kahrizi, D.; Arkan, E. Comparison of different properties of zinc oxide nanoparticles synthesized by the green (using Juglans regia L. leaf extract) and chemical methods. J. Mol. Liq. 2019, 286, 110831. [Google Scholar] [CrossRef]
  120. Hu, D.; Si, W.; Qin, W.; Jiao, J.; Li, X.; Gu, X.; Hao, Y. Cucurbita pepo leaf extract induced synthesis of zinc oxide nanoparticles, characterization for the treatment of femoral fracture. J. Photochem. Photobiol. B Biol. 2019, 195, 12–16. [Google Scholar] [CrossRef] [PubMed]
  121. Hussain, A.; Oves, M.; Alajmi, M.F.; Hussain, I.; Amir, S.; Ahmed, J.; Rehman, M.T.; El-Seedi, H.R.; Ali, I. Biogenesis of ZnO nanoparticles using Pandanus odorifer leaf extract: Anticancer and antimicrobial activities. RSC Adv. 2019, 9, 15357–15369. [Google Scholar] [CrossRef] [Green Version]
  122. Kahsay, M.H.; Tadesse, A.; RamaDevi, D.; Belachew, N.; Basavaiah, K. Green synthesis of zinc oxide nanostructures and investigation of their photocatalytic and bactericidal applications. RSC Adv. 2019, 9, 36967–36981. [Google Scholar] [CrossRef]
  123. Prasad, A.R.; Garvasis, J.; Oruvil, S.K.; Joseph, A. Bio-inspired green synthesis of zinc oxide nanoparticles using Abelmoschusesculentus mucilage and selective degradation of cationic dye pollutants. J. Phys. Chem. Solids 2019, 127, 265–274. [Google Scholar] [CrossRef]
  124. Alamdari, S.; Ghamsari, M.S.; Lee, C.; Han, W.; Park, H.H.; Tafreshi, M.J.; Afarideh, H.; Ara, M.H.M. Preparation and characterization of Zinc oxide nanoparticles using leaf extract of Sambucus ebulus. Appl. Sci. 2020, 10, 3620. [Google Scholar] [CrossRef]
  125. Liu, H.; Kang, P.; Liu, Y.; An, Y.; Hu, Y.; Jin, X.; Cao, X.; Qi, Y.; Ramesh, T.; Wang, X. Zinc oxide nanoparticles synthesised from the Vernonia amygdalina shows the anti-inflammatory and antinociceptive activities in the mice model. Artif. Cells Nanomed. Biotechnol. 2020, 48, 1068–1078. [Google Scholar] [CrossRef]
  126. Naseer, M.; Aslam, U.; Khalid, B.; Chen, B. Green route to synthesize Zinc oxide Nanoparticles using leaf extracts of Cassia fistula and Melia azadarach and their antibacterial potential. Sci. Rep. 2020, 10, 9055. [Google Scholar] [CrossRef]
  127. Sharma, S.; Kumar, K.; Thakur, N.; Chauhan, S.; Chauhan, M.S. The effect of shape and size of ZnO nanoparticles on their antimicrobial and photocatalytic activities: A green approach. Bull. Mater. Sci. 2020, 43, 20. [Google Scholar] [CrossRef]
  128. Vinayagam, R.; Selvaraj, R.; Arivalagan, P.; Varadavenkatesan, T. Synthesis, characterization and photocatalytic dye degradation capability of Calliandra haematocephala-mediated zinc oxide nanoflowers. J. Photochem. Photobiol. B Biol. 2020, 203, 111760. [Google Scholar] [CrossRef]
  129. Zhang, H.; Liang, Z.; Zhang, J.; Wang, W.P.; Zhang, H.; Lu, Q. Zinc oxide nanoparticle synthesized from Euphorbia fischeriana root inhibits the cancer cell growth through modulation of apoptotic signaling pathways in lung cancer cells. Arab. J. Chem. 2020, 13, 6174–6183. [Google Scholar] [CrossRef]
  130. Vinayagam, R.; Pai, S.; Varadavenkatesan, T.; Pugazhendhi, A.; Selvaraj, R. Characterization and photocatalytic activity of ZnO nanoflowers synthesized using Bridelia retusa leaf extract. Appl. Nanosci. 2021, 1–10. [Google Scholar] [CrossRef]
  131. Ali, K.; Dwivedi, S.; Azam, A.; Saquib, Q.; Al-Said, M.S.; Alkhedhairy, A.A.; Musarrat, J. Aloe vera extract functionalized zinc oxide nanoparticles as nanoantibiotics against multi-drug resistant clinical bacterial isolates. J. Colloid Interface Sci. 2016, 472, 145–156. [Google Scholar] [CrossRef]
  132. Sharmila, G.; Thirumarimurugan, M.; Muthukumaran, C. Green synthesis of ZnO nanoparticles using Tecoma castanifolia leaf extract: Characterization and evaluation of its antioxidant, bactericidal and anticancer activities. Microchem. J. 2019, 145, 578–587. [Google Scholar] [CrossRef]
  133. Wang, D.; Liu, H.; Ma, Y.; Qu, J.; Guan, J.; Lu, N.; Lu, Y.; Yuan, X. Recycling of hyper-accumulator: Synthesis of ZnO nanoparticles and photocatalytic degradation for dichlorophenol. J. Alloys Compd. 2016, 680, 500–505. [Google Scholar] [CrossRef]
  134. Saemi, R.; Taghavi, E.; Jafarizadeh-Malmiri, H.; Anarjan, N. Fabrication of green ZnO nanoparticles using walnut leaf extract to develop an antibacterial film based on polyethylene–starch–ZnO NPs. Green Process. Synthesis 2021, 10, 112–124. [Google Scholar] [CrossRef]
  135. Sun, Q.; Li, J.; Le, T. Zinc oxide nanoparticle as a novel class of antifungal agents: Current advances and future perspectives. J. Agric. Food Chem. 2018, 66, 11209–11220. [Google Scholar] [CrossRef]
  136. Sharma, D.; Sabela, M.I.; Kanchi, S.; Mdluli, P.S.; Singh, G.; Stenström, T.A.; Bisetty, K. Biosynthesis of ZnO nanoparticles using Jacaranda mimosifolia flowers extract: Synergistic antibacterial activity and molecular simulated facet specific adsorption studies. J. Photochem. Photobiol. B Biol. 2016, 162, 199–207. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  137. Vijayakumar, S.; Vaseeharan, B.; Sudhakaran, R.; Jeyakandan, J.; Ramasamy, P.; Sonawane, A.; Padhi, A.; Velusamy, P.; Anbu, P.; Faggio, C. Bioinspired Zinc oxide nanoparticles using Lycopersicon esculentum for antimicrobial and anticancer applications. J. Clust. Sci. 2019, 30, 1465–1479. [Google Scholar] [CrossRef]
  138. Tang, K.S. The current and future perspectives of zinc oxide nanoparticles in the treatment of diabetes mellitus. Life Sci. 2019, 239, 117011. [Google Scholar] [CrossRef]
  139. Tian, W.; Wang, C.; Li, D.; Hou, H. Novel anthraquinone compounds as anticancer agents and their potential mechanism. Future Med. Chem. 2020, 12, 627–644. [Google Scholar] [CrossRef]
  140. Agarwal, H.; Nakara, A.; Shanmugam, V.K. Anti-inflammatory mechanism of various metal and metal oxide nanoparticles synthesized using plant extracts: A review. Biomed. Pharmacother. 2019, 109, 2561–2572. [Google Scholar] [CrossRef]
  141. Moghaddas, S.M.T.H.; Elahi, B.; Javanbakht, V. Biosynthesis of pure zinc oxide nanoparticles using Quince seed mucilage for photocatalytic dye degradation. J. Alloy. Compd. 2020, 821, 153519. [Google Scholar] [CrossRef]
  142. Kiran Kumar, A.B.V.; Saila, E.S.; Narang, P.; Aishwarya, M.; Raina, R.; Gautam, M.; Shankar, E.G. Biofunctionalization and biological synthesis of the ZnO nanoparticles: The effect of Raphanus sativus (white radish) root extract on antimicrobial activity against MDR strain for wound healing applications. Inorg. Chem. Commun. 2019, 100, 101–106. [Google Scholar] [CrossRef]
  143. Gao, Y.; Han, Y.; Cui, M.; Tey, H.L.; Wang, L.; Xu, C. ZnO nanoparticles as an antimicrobial tissue adhesive for skin wound closure. J. Mater. Chem. B 2017, 5, 4535–4541. [Google Scholar] [CrossRef]
  144. Lin, C.C.; Lee, M.H.; Chi, M.H.; Chen, C.J.; Lin, H.Y. Preparation of Zinc oxide nanoparticles containing spray and barrier films for potential photoprotection on wound healing. ACS Omega 2019, 4, 1801–1809. [Google Scholar] [CrossRef]
  145. Nosrati, H.; Khodaei, M.; Banitalebi-Dehkordi, M.; Alizadeh, M.; Asadpour, S.; Sharifi, E.; Ai, J.; Soleimannejad, M. Preparation and characterization of poly (ethylene oxide)/zinc oxide nanofibrous scaffold for chronic wound healing applications. Polim. Med. 2020, 50, 41–51. [Google Scholar] [CrossRef]
  146. Bagheri, M.; Validi, M.; Gholipour, A.; Makvandi, P.; Sharifi, E. Chitosan nanofiber biocomposites for potential wound healing applications: Antioxidant activity with synergic antibacterial effect. Bioeng. Transl. Med. 2021, e10254. [Google Scholar] [CrossRef]
  147. Bazak, R.; Houri, M.; Achy, S.E.; Hussein, W.; Refaat, T. Passive targeting of nanoparticles to cancer: A comprehensive review of the literature. Mol. Clin. Oncol. 2014, 2, 904–908. [Google Scholar] [CrossRef] [Green Version]
  148. Ghazali, N.A.B.; Mani, M.P.; Jaganathan, S.K. Green-synthesized Zinc oxide nanoparticles decorated nanofibrous polyurethane mesh loaded with virgin coconut oil for tissue engineering application. Curr. Nanosci. 2018, 14, 280–289. [Google Scholar] [CrossRef]
  149. Laurenti, M.; Cauda, V. ZnO nanostructures for tissue engineering applications. Nanomaterials 2017, 7, 374. [Google Scholar] [CrossRef] [Green Version]
  150. Medina-Cruz, D.; Mostafavi, E.; Vernet-Crua, A.; Cheng, J.; Shah, V.; Cholula-Diaz, J.L.; Guisbiers, G.; Tao, J.; García-Martín, J.M.; Webster, T.J. Green nanotechnology-based drug delivery systems for osteogenic disorders. Expert Opin. Drug Deliv. 2020, 17, 341–356. [Google Scholar] [CrossRef]
  151. Cruz, D.M.; Mostafavi, E.; Vernet-Crua, A.; Barabadi, H.; Shah, V.; Cholula-Díaz, J.-L.; Guisbiers, G.; Webster, T.J. Green nanotechnology-based zinc oxide (ZnO) nanomaterials for biomedical applications: A review. J. Phys. Mater. 2020, 3, 034005. [Google Scholar] [CrossRef]
  152. Shubha, P.; Likhith Gowda, M.; Namratha, K.; Manjunatha, H.B.; Byrappa, K. In vitro and in vivo evaluation of green-hydrothermal synthesized ZnO nanoparticles. J. Drug Deliv. Sci. Technol. 2019, 49, 692–699. [Google Scholar] [CrossRef]
  153. Shafique, S.; Jabeen, N.; Ahmad, K.S.; Irum, S.; Anwaar, S.; Ahmad, N.; Alam, S.; Ilyas, M.; Khan, T.F.; Hussain, S.Z. Green fabricated zinc oxide nanoformulated media enhanced callus induction and regeneration dynamics of Panicum virgatum L. PLoS ONE 2020, 15, e0230464. [Google Scholar] [CrossRef]
Figure 1. Possible antibacterial mechanisms of plant-mediated zinc oxide nanoparticles.
Figure 1. Possible antibacterial mechanisms of plant-mediated zinc oxide nanoparticles.
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Figure 2. Possible antifungal mechanism of plant-mediated zinc oxide nanoparticles. (a) Hypothetical anticandidal mechanisms of zinc oxide nanoparticles, and (b) plausible mechanisms of action of zinc oxide nanoparticle-induced ROS generation for their anticandidal activity.
Figure 2. Possible antifungal mechanism of plant-mediated zinc oxide nanoparticles. (a) Hypothetical anticandidal mechanisms of zinc oxide nanoparticles, and (b) plausible mechanisms of action of zinc oxide nanoparticle-induced ROS generation for their anticandidal activity.
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Figure 3. Possible antioxidant mechanisms of plant-mediated zinc oxide nanoparticles.
Figure 3. Possible antioxidant mechanisms of plant-mediated zinc oxide nanoparticles.
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Figure 4. Possible antidiabetic mechanism of plant-mediated zinc oxide nanoparticles.
Figure 4. Possible antidiabetic mechanism of plant-mediated zinc oxide nanoparticles.
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Figure 5. Possible anticancer mechanism of plant-mediated zinc oxide nanoparticles.
Figure 5. Possible anticancer mechanism of plant-mediated zinc oxide nanoparticles.
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Figure 6. Possible anti-inflammatory mechanisms of plant-mediated zinc oxide nanoparticles.
Figure 6. Possible anti-inflammatory mechanisms of plant-mediated zinc oxide nanoparticles.
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Figure 7. Possible photocatalytic mechanism of plant-mediated zinc oxide nanoparticles.
Figure 7. Possible photocatalytic mechanism of plant-mediated zinc oxide nanoparticles.
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Figure 8. Possible mechanisms of plant-mediated zinc oxide nanoparticles in a targeted drug delivery system.
Figure 8. Possible mechanisms of plant-mediated zinc oxide nanoparticles in a targeted drug delivery system.
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Table 1. Morphology of plant-mediated zinc oxide nanoparticles and their applications.
Table 1. Morphology of plant-mediated zinc oxide nanoparticles and their applications.
Plant NamePlant Part UsedSize
(nm)
Shape/
Morphology
ApplicationsReference
ZINC NITRATE
Solanum nigrumLeaf29Quasi-sphericalAntibacterialRamesh et al. [51]
Borassus flabelliferFruit55Rod likeDrug deliveryVimala et al. [52]
Phyllanthus niruriLeaf25Quasi-sphericalPhotocatalyticAnbuvannan et al. [53]
Anisochilus carnosusLeaf30–40Quasi-sphericalAntibacterial and PhotocatalyticAnbuvannan et al. [54]
Hibiscus subdariffaLeaf12–46SphericalAntibacterial and Anti-diabeticBala et al. [35]
Plectranthus amboinicusLeaf20–50Spherical and hexagonalAntibacterial, Antibiofilm and LarvicidalVijayakumar et al. [55]
Carissa edulisFruit50–55Flower shapePhotocatalyticFowsiya et al. [56]
Rosa caninaFruit<50SphericalAntibacterial, Antioxidant and AnticancerJafarirad et al. [57]
Nephelium lappaceumPeel25–40SphericalPhotocatalyticKarnan and Selvakumar [58]
Limonia acidissimaLeaf12–53SphericalAntibacterial (TB)Patil and Taranath [59]
Carica papayaMilk latex11–26HexagonalPhotocatalytic and AntibacterialSharma [60]
Boswellia ovalifoliolataBark20SphericalAntimicrobialSupraja et al. [61]
Camellia sinensisLeaf-HexagonalPhotocatalyticNava et al. [62]
Ceropegia candelabrumLeaf12–35Hexagonal wurtziteAntibacterial and AntioxidantMurali et al. [5]
Ziziphus nummulariaLeaf12–26Spherical and irregularAntifungal and AnticancerPadalia and Chanda [7]
Vaccinium arctostaphylosFruit13SphericalAnti-diabeticBayrami et al. [63]
Citrus sinensisPeel12–24Hexagonal prisms and oval spheres; highly irregular sponge-likePhotocatalyticLuque et al. [64]
Mangifera indicaLeaf45–60Nearly spherical and hexagonal quartziteAntioxidant and AnticancerRajeshkumar et al. [65]
Costus pictusLeaf40Hexagonal, rod-shaped and sphericalAntimicrobial and AnticancerSuresh et al. [66]
Solanum torvumLeaf28SphericalToxicological effect in Wistar albino ratsEzealisiji et al. [67]
Artabotrys hexapetaluLeaf20–30Spherical and rod-likeAntibacterial and PhotocatalyticShanavas et al. [68]
Bambusa vulgaris
Annona squamosaLeaf20–50Hexagonal and quasi hexagonal plate likeAntibacterial and AnticancerRuddaraju et al. [69]
Scutellaria baicalensisRoot33–99SphericalAntioxidant and AnticancerTettey and Shin [70]
Albizia lebbeckBark66Irregular sphericalAntibacterial, Antioxidant, Cytotoxic and AntiproliferativeUmar et al. [26]
Citrus sinensisPeel33HexagonalAntibacterial, Antifungal and AnticancerGao et al. [19]
Beta vulgarisPlant20SphericalAntibacterial and AntifungalPillai et al. [25]
Cinnamomum tamala30Rod
Cinnamomum verum46Spherical
Brassica oleracea var. italica47Spherical
Crotalaria verrucosaLeaf16–38HexagonalAntibacterial and AnticancerSana et al. [71]
ZINC NITRATE HEXAHYDRATE
Azadirachta indicaLeaf40SphericalAntimicrobialElumalai and Velmurugan [13]
Vitex trifoliaLeaf30Nearly spherical and hexagonalAntimicrobial and PhotocatalyticElumalai et al. [72]
Plectranthus amboinicusLeaf88Rod shapePhotocatalyticFu and Fu [73]
Polygala tenuifoliaRoot33–73SphericalAntioxidant and
Anti-inflammatory
Nagajyothi et al. [17]
Allium sativum and A. cepaBulbs14–70SphericalPhotocatalytic activityStan et al. [74]
Petroselinum crispumLeaf
Pongamia pinnataLeaf100Spherical, nanorod and hexagonalAntibacterialSundrarajan et al. [75]
Cassia fistulaLeaf~5–15Sponge like irregularPhotocatalytic, Antioxidant and AntibacterialSuresh et al. [76]
Artocarpus gomezianusFruit11.53SphericalPhotocatalytic and AntioxidantSuresh et al. [77]
Corymbia citriodoraLeaf64PolyhedronPhotocatalyticZheng et al. [78]
Azadirachta indicaLeaf10–30HexagonalAntibacterial, Antioxidant and PhotocatalyticMadan et al. [36]
Terminalia chebulaFruit12Roughly sphericalPhotocatalyticRana et al. [79]
Citrullus colocynthisFruit85–100FlowerAntibacterial, Antioxidant and AnticancerAzizi et al. [80]
Seed20–35Hexagonal
Pulp30–80Irregular polygons
Ocimum tenuiflorumLeaf10–20SphericalNon-enzymatic glucose sensorDayakar et al. [81]
Cochlospermum religiosumLeaf∼76HexagonalAntibacterial and AntimitoticMahendra et al. [82]
Azadirachta indica, Hibiscus rosa-sinensis, Murraya koenigii, Moringa oleifera and Tamarindus indicaLeaf27–54SphericalAntioxidant and Anti-diabeticRehana et al. [22]
Eucalyptus globulusLeaf11.6SphericalAntioxidant and PhotocatalyticSiripireddy and Mandal [83]
Acacia senegalArabic gum10SphericalPhotocatalyticTaghavi Fardood et al. [84]
Conyza canadensisLeafIrregularAntibacterial and PhotocatalyticAli et al. [85]
Garcinia mangostanaFruit pericarp21SphericalPhotocatalyticAminuzzaman et al. [86]
Andrographis paniculataLeaf57Spherical, oval and hexagonalAntioxidant, Anti-diabetic and Anti-inflammatoryRajakumar et al. [34]
Barleria gibsoniLeaf50Hexagonal (Wurtzite)Wound healingShao et al. [87]
Anacardium occidentaleLeaf33HexagonalAnticancerZhao et al. [88]
Gracilaria edulisAqueous20–50Hexagonal (Wurtzite) rodAnticancerAsik et al. [89]
Populus ciliataLeaf60–70Sphere likeAntibacterialHafeez et al. [90]
Mentha pulegiumLeaf40Quasi- sphericalAntimicrobialRad et al. [91]
Laurus nobilisLeaf20–30Spherical and hexagonalAntibacterial and PhotocatalyticChemingui et al. [92]
Justicia wynaadensisLeaf∼39HexagonalAntimitotic and DNA-binding activitiesHemanth Kumar et al. [8]
Artocarpus heterophyllusLeaf12–24SphericalAnticancerMajeed et al. [93]
Eucalyptus globulesLeaf52–70Spherical or globularAntifungalAhmad et al. [94]
Camellia sinensisLeaf11SphereDrug deliveryAkbarian et al. [95]
Cinnamomum verumBark~45Hexagonal wurtziteAntibacterialAnsari et al. [2]
Ziziphus jujubaFruit29SphericalPhotocatalyticGolmohammadi et al. [96]
Mussaenda frondosaLeaf8–15HexagonalAntibacterial, Antioxidant, Antidiabetic, Anticancer, Anti-inflammatory and PhotocatalyticJayappa et al. [97]
Stem9–12Spherical
Leaf-derived callus5–7
Aegle marmelosJuice~20HexagonalAntibacterial, Antioxidant and PhotocatalyticMallikarjunaswamy et al. [98]
Zea maysHusk300–550Flower-likeAntibacterial and AntioxidantQuek et al. [31]
Artocarpus heterophyllusPeel380–900Cauliflower-like
Punica granatumPeel260–500Nanoflowers
Deverra tortuosaPlant9–31HexagonalAnticancerSelim et al. [99]
ZINC ACETATE
Passiflora caeruleaLeaf70SphericalAntibacterialSanthoshkumar et al. [100]
Cucumis melo inodorusRough shell25–40Crystals with pseudo sphericalAnticancerMahdizadeh et al. [101]
Hyssops officinalisPlant20–40Pseudo sphericalAnti-angiogenesis, Anti-inflammatory and AnticancerRahimi Kalateh Shah Mohammad et al. [102]
Syzgium cuminiSeed50–60SphericalLarvicidalRoopan et al. [38]
Lycopersicon esculentumLeaf10–50Hexagonal wurtziteAntimicrobial and AnticancerVijayakumar et al. [103]
Costus igneusLeaf25–40HexagonalAntibacterial, Antioxidant and AntidiabeticVinotha et al. [33]
Rehmanniae radixPlant10–12Rod shapeAnticancerCheng et al. [104]
∼200 Spherical
Cratoxylum formosumLeaf∼500NanosheetsAntibacterial and AnticancerJevapatarakul et al. [105]
Syzygium cuminiLeaf64–78SphericalPhotocatalyticRafique et al. [106]
Hyssopus officinalisLeaf20–40Pseudo sphericalAnticancer activityRahimi Kalateh Shah Mohammad et al. [107]
Thlaspi arvensePlant70–90FlowerAntibacterial and PhotocatalyticUllah et al. [108]
Raphanus sativusLeaf66SphericalAnticancerUmamaheshwari et al. [29]
ZINC ACETATE DIHYDRATE
Anchusa italicaFlower~8–14HexagonalAntimicrobial and CytotoxicityAzizi et al. [6]
Lobelia leschenaultianaLeaf20–65Spherical and hexagonalAcaricidalBanumathi et al. [109]
Mimosa pudicaLeaf27Wurtzite and hexagonalPhotocatalyticFatimah et al. [110]
Coffea arabiocaSeed46Wurtzite and hexagonalPhotocatalytic
Pongamia pinnataSeed30–40SphericalAnticancer and AntibiofilmMalaikozhundan et al. [111]
Couroupita guianensisLeafHexagonalAntibacterialSathishkumar et al. [112]
Catharanthus roseusLeaf50–92Hexagonal wurtziteAntibacterialGupta et al. [113]
Nyctanthes arbor-tristisFlower12–32AntifungalJamdagni et al. [32]
Coffea arabicaSeeds26SphericalWound-healingKhatami et al. [114]
Ferulago angulataBoiss32–36SpheroidPhotocatalyticMehr et al. [115]
Averrhoa bilimbiFruit37SphericalPhotoelectrodeRamanarayanan et al. [116]
Coccinia abyssinicaTuber10.4HexagonalAntibacterial and AntioxidantSafawo et al. [117]
Atalantia monophyllaLeaf30Spherical and hexagonalAntimicrobialVijayakumar et al. [103]
Kalanchoe pinnataLeaf24Hexagonal and sphericalAntioxidant, Anticancer and Anti-inflammatoryAgarwal and Shanmugam [21]
Berberis aristataLeaf20–40Needle likeAntibacterial and AntioxidantChandra et al. [118]
Juglans regiaLeaf45–65SphericalAntibacterial and AnticancerDarvishi et al. [119]
95–150Flower
Cucurbita pepoLeaf8SphericalCytotoxicityHu et al. [120]
Pandanus odoriferLeaf90SphericalAntibacterial and AnticancerHussain et al. [121]
Dolichos lablabLeaf29Hexagonal wurtziteBactericidal and PhotocatalyticKahsay et al. [122]
Abelmoschus esculentusOkra mucilage29–70Spherical, elongated, and rod-likePhotocatalyticPrasad et al. [123]
Musa acuminataPeel30−80Triangular-likePhotocatalyticAbdullah et al. [40]
Mucuna pruriensSeed60Flower and sphericalAntibacterialAgarwal et al. [27]
Sambucus ebulusLeaf25−30SphericalAntibacterial, Antioxidant and PhotocatalyticAlamdari et al. [124]
Vernonia amygdalinaLeaf20–40CylindricalAnti-inflammatoryLiu et al. [125]
Cassia fistula and Melia azadarachLeaf3–68SphericalAntibacterialNaseer et al. [126]
Aloe veraLeaf∼65HexagonalAntibacterial and PhotocatalyticSharma et al. [127]
60–180Spherical
40–45Cuboidal and Rod
Calliandra haematocephalaLeaf19FlowerPhotocatalyticVinayagam et al. [128]
Euphorbia fischerianaRoot30SphericalAnticancerZhang et al. [129]
Myristica fragransFruit43–83Spherical or ellipticalAntibacterial, Antiparasitic, Antioxidant, Antidiabetic, Anticancer and PhotocatalyticFaisal et al. [11]
Bridelia retusaLeaf11Flower-shapePhotocatalyticVinayagam et al. [130]
ZINC SULPHATE
Aloe barbadensisLeaf8–18Spherical, oval and hexagonalAntibacterialAli et al. [131]
Bauhinia tomentosaLeaf22–94HexagonalAntibacterialSharmila et al. [30]
Trianthema portulacastrumPlant25–90SphericalAntibacterial, Antifungal, Antioxidant, Anticancer and PhotocatalyticKhan et al. [39]
OTHERS
Tecoma castanifoliaLeaf70–75SphericalAntibacterial, Antioxidant, and AnticancerSharmila et al. [132]
Trifolium pratenseFlower60–70AgglomeratedAntibacterialDobrucka and Długaszewska [15]
Jacaranda mimosifoliaFlower2–4SphericalAntibacterialSharma et al. [60]
Heritiera fomes and Sonneratia apetalaBark and leaf40–50Antibacterial, Antioxidant, Anti-diabetic and Anti-inflammatoryThatoi et al. [16]
Sedum alfrediiShoots100Columnar in shapePhotocatalyticWang et al. [133]
Juglans regiaLeafAntifungalSaemi et al. [134]
PlantsAntifungalSun et al. [135]
Table 2. Antibacterial and antifungal activity of plant-mediated zinc oxide nanoparticles.
Table 2. Antibacterial and antifungal activity of plant-mediated zinc oxide nanoparticles.
Plant NamePlant Part UsedPathogen NameMinimum Inhibitory Concentration (MIC) *
(mg·mL−1)
ResultsReference
ANTIBACTERIAL ACTIVITY
Anisochilus carnosusLeafSalmonella paratyphi, Vibrio cholerae, Staphylococcus aureus and Escherichia coli-Showed antibacterial activity towards various human pathogensAnbuvannan et al. [54]
Hibiscus subdariffaLeafEscherichia coli and Staphylococcus aureus0.05Exerted better bactericidal property on S. aureus and E. coliBala et al. [35]
Azadirachta indicaLeafStaphylococcus aureus, Pseudomonas aeruginosa, B. subtilis, Proteus mirabilis, E. coli0.006–0.05Showed significant inhibition against bacterial strains in a dose-dependent mannerElumalai and Velmurugan [13]
Vitex trifoliaLeafStaphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli0.006–0.05Showed outstanding antibacterial activity against Gram positive and Gram negative bacteriaElumalai et al. [72]
Pongamia pinnataLeafStaphylococcus aureus and Escherichia coli0.1Superior antibacterial activity against Gram positive and Gram negative bacteriaSundrarajan et al. [75]
Cassia fistulaLeafKlebsiella aerogenes, Escherichia coli, Pseudomonas desmolyticum and Staphylococcus aureus0.5–0.1Showed an excellent bactericidal activity against pathogenic bacteriaSuresh et al. [76]
Plectranthus amboinicusLeafStaphylococcus aureus≤0.01Controlled the growth of methicillin-resistant S. aureus biofilmVijayakumar et al. [55]
Aloe barbadensisLeafEscherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus2.2–2.4Significant antibacterial activity against extended spectrum β-lactamases (ESBL) positive E. coli, P. aeruginosa, and methicillin resistant S. aureus (MRSA) clinical isolatesAli et al. [131]
Anchusa italicaFlowerBacillus megaterium, Stapphylococcus aureus, Escherichia coli and Salmonella typhimurium0.016–0.032Showed antimicrobial activity against Gram positive and Gram negative bacteria decreased with increasing the heat treating temperatureAzizi et al. [6]
Trifolium pratenseFlowerEscherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureusExhibited high activity against standard and clinical strain of Gram-positive and Gram-negative bacteriaDobrucka and Długaszewska [15]
Rosa caninaFruitListeria monocytogenes, Staphylococcus aureus and Escherichia coli0.5–1Relatively good antibacterial activity against Gram positive and Gram negative bacteriaJafarirad et al. [57]
Azadirachta indicaLeafKlebsiella aerogenes and Staphylococcus aureus0.1–1Showed significant antibacterial activity against K. aerogenes and S. aureusMadan et al. [36]
Limonia acidissimaLeafMycobacterium tuberculosis0.0125Control the growth of M. tuberculosisPatil and Taranath [59]
Carica papayaMilkPseudomonas aeruginosa, Staphylococcus aureus, Klebsiella aerogenes and Pseudomonas desmolyticum0.2–0.4Showed significant antibacterial activity against bacterial stainsSharma [60]
Jacaranda mimosifoliaFlowerEscherichia coli and Enterococcus faecium0.1Enhanced antibacterial activity against pathogenic strainsSharma et al. [136]
Boswellia ovalifoliolataBarkSphingobacterium thalpophilum, Uncultured organism clone, Ochrobactrum sp., Uncultured Achromobacter sp., Uncultured bacterium clone, Sphingobacterium sp., Acinetobacter sp., Uncultured soil bacterium, Ochrobactrum sp., Uncultured bacterium-Showed good antibacterial activity at 170 ppm compared to 50 and 100 ppmSupraja et al. [61]
Heritiera fomesBark and LeafShigella flexneri0.1Displayed positive inhibition activity against S. flexneriThatoi et al. [16]
Sonneratia apetala
Citrullus colocynthisFruit, Seed and PulpBacillus subtilis, Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coliInhibited the growth of medically significant pathogenic Gram positive and Gram negative bacteriaAzizi et al. [80]
Cochlospermum religiosumLeafBacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli0.004–0.312Showed significant inhibition against Gram positive and Gram negative bacteriaMahendra et al. [82]
Pongamia pinnataSeedBacillus licheniformis, Pseudomonas aeruginosa, Vibrio parahaemolyticus0.025Effectively inhibited Gram positive and Gram negative bacteria growthMalaikozhundan et al. [111]
Ceropegia candelabrumLeafStaphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi0.1Showed significant inhibition against Gram positive and Gram negative bacterial pathogensMurali et al. [5]
Passiflora caeruleaLeafKlebsiella sp., Streptococcus sp., Enterococcus sp., and Escherichia coli-Showed very good inhibition of urinary tract infection causing microbesSanthoshkumar et al. [100]
Couroupita guianensisLeafBacillus cereus, Klebsiella pneumoniae, Escherichia coli, Micrococcus luteus, Salmonella typhi,and Vibrio cholerae0.005Exhibited excellent dose dependent bactericidal effect against human pathogensSathishkumar et al. [112]
Conyza canadensisLeafEscherichia coli and Staphylococcus aureus0.055–0.094Exhibited strong antibacterial activityAli et al. [85]
Catharanthus roseusLeafStaphylococcus aureus, Streptococcus pyogenes, Bacillus cereus, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli1.5Displayed good antibacterial activity against pathogenic bacteriaGupta et al. [113]
Coccinia abyssinicaTuberBacillus coagulans, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhimurium and Sphingomonas paucimobilis0.001–0.005Showed effective growth inhibition activity against Gram negative and Gram positive bacteriaSafawo et al. [117]
Bauhinia tomentosaLeafBacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosaExhibited better antibacterial activity against Gram negative bacteria than Gram positive bacteriaSharmila et al. [30]
Costus pictusLeafStaphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella paratyphi0.1Exhibited strong antimicrobial behavior against bacterial speciesSuresh et al. [66]
Atalantia monophyllaLeafBacillus subtilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pnemoniaeShowed antimicrobial potential against pathogenic bacteriaVijayakumar et al. [103]
Berberis aristataLeafEscherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Bacillus cereus and Serratia marcescens0.064–0.256Displayed antibacterial activity against urinary tract infection causing pathogensChandra et al. [118]
Laurus nobilisLeafEscherichia coli1.2Proved as an effective antibacterial agent against E. coliChemingui et al. [92]
Juglans regiaLeafEscherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii0.2Exerted bactericidal property on resistant strainsDarvishi et al. [119]
Populus ciliataLeafEscherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Streptococcus pyogeneShowed significant antibacterial potential on test pathogensHafeez et al. [90]
Pandanus odoriferLeafBacillus subtilis, Escherichia coli0.05Showed significant antibacterial potential on test pathogensHussain et al. [121]
Dolichos lablabLeafBacillus pumilus and Sphingomonas paucimobilis5Showed a bactericidal activity for pathogenic Gram positive and Gram negative bacteriaKahsay et al. [122]
Trianthema portulacastrumPlantStaphylococcus aureus and Escherichia coliShowed significant antibacterial propertyKhan et al. [39]
Mentha pulegiumLeafStaphylococcus aureus and Escherichia coli0.2Exhibited significant antimicrobial potential on some food-borne pathogensRad et al. [91]
Annona squamosaLeafEscherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecium0.006–0.012Synergetic antibacterial potential against wound/burn infection causing bacteriaRuddaraju et al. [69]
Artabotrys hexapetaluLeafStreptococcus and SerratiaShowed better antibacterial performance against Gram positive and Gram negative bacteriaShanavas et al. [68]
Bambusa vulgaris
Tecoma castanifoliaLeafBacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa0.075–0.1Excellent antibacterial activity against Gram positive and Gram negative bacteriaSharmila et al. [132]
Albizia lebbeckBarkBacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae,and Salmonella typhi35.5Strong antibacterial potential against Gram-negative and Gram-positive bacterial pathogensUmar et al. [26]
Lycopersicon esculentumLeafEnterococcus faecalis and Proteus vulgaris0.008–0.01A notable reduction in bacterial growth was observedVijayakumar et al. [137]
Costus igneusLeafStreptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris,and Vibrio parahaemolyticus0.04–0.07Showed promising antibacterial activity against targeted pathogenic bacteriaVinotha et al. [33]
Mucuna pruriensSeedBacillus subtilis0.02Showed concentration dependent inhibition of the growth of B. subtilisAgarwal et al. [27]
Sambucus ebulusLeafBacillus cereus, Staphylococcus aureus,and Escherichia coli0.1Exhibited antibacterial activity over all three bacteriaAlamdari et al. [124]
Cinnamomum verumBarkEscherichia coli and Staphylococcus aureus0.062–0.125Inhibited the growth of harmful pathogensAnsari et al. [2]
Citrus sinensisFruit PeelEscherichia coli and Staphylococcus aureus0.020–0.040Showed stronger antibacterial activityGao et al. [19]
Mussaenda frondosaLeaf, Stem and Leaf-derived callusStaphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa0.019–0.185Showed inhibition against bacterial strainsJayappa et al. [97]
Cratoxylum formosumLeafBacillus subtilis, Staphylococcus epidermidis, Escherichia coli5Inhibited Gram positive and Gram negative bacterial growthJevapatarakul et al. [105]
Aegle marmelosJuiceStaphylococcus aureus, Bacillus cereus, Micrococcus luteus, Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, Pseudomonas fluorescens, Pseudomonas aeruginosa and Salmonella enteritidis3.84–8.65Showed good bactericidal activityMallikarjunaswamy et al. [98]
Cassia fistula and Melia azadarachLeafEscherichia coli and Staphylococcus aureus0.05Showed strong antimicrobial activity against clinical pathogensNaseer et al. [126]
Beta vulgarisPlantEscherichia coli and Staphylococcus aureusShown antibacterial activity both Gram negative and Gram positive bacteriaPillai et al. [25]
Cinnamomum tamala
Cinnamomum verum
Brassica oleracea
Zea maysHuskEnterococcus faecalisExcellent antibacterial activity against E. faecalis compared to zinc oxide synthesized without plant extract and commercial zinc oxideQuek et al. [31]
Artocarpus heterophyllusPeel
Punica granatum
Crotalaria verrucosaLeafEscherichia coli, Staphylococcus aureus, Proteus vulgaris,and Klebsiella pneumonia0.1Exhibited significant antibacterial potentiality against Gram positive and Gram negative pathogenic bacteriaSana et al. [71]
Aloe veraLeafBacillus subtilis, Staphylococcus aureus and Escherichia coli0.195–3.125Showed antibacterial activity against pathogenic bacteriaSharma et al. [127]
Thlaspi arvensePlantEscherichia coli0.015Exhibited a significant antibacterial activity against Gram negative E. coliUllah et al. [108]
Myristica fragransFruitKlebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa,and Staphylococcus aureus1Shown successful capacity against bacterial strainsFaisal et al. [11]
ANTIFUNGAL ACTIVITY
Azadirachta indicaLeafCandida albicans and Candida tropicalis0.006–0.05Showed significant inhibition against fungal strains in a dose-dependent mannerElumalai and Velmurugan [13]
Vitex trifoliaLeafCandida albicans and Candida tropicalis0.006–0.05Excellent antifungal activity against human pathogenic fungiElumalai et al. [72]
Boswellia ovalifoliolataBarkMeyerozyma caribbica, Aspergillus parvisclerotigenus, Meyerozyma guilliermondii, Rhizopus oryzae, Uncultured fungus clone, Aspergillus oryzae, Trichoderma asperellumShowed good antifungal activity at 170 ppm compared to 50 and 100 ppmSupraja et al. [61]
Pongamia pinnataSeedCandida albicans0.05Effectively inhibited the biofilm formation of C. albicansMalaikozhundan et al. [111]
Ziziphus nummulariaLeafCandida albicans, Candida glabrata and Cryptococcus neoformans1.25–10Showed very good antifungal activity against clinical isolatesPadalia and Chanda [7]
Nyctanthes arbor-tristisFlowerAlternaria alternata, Aspergillus niger, Botrytis cinerea, Fusarium oxysporum and Penicillium expansum0.016Showed good antifungal potential against fungal phytopathogensJamdagni et al. [32]
Costus pictusLeafAspergillus niger and Candida albicans0.1Exhibited strong antimicrobial behavior against fungal speciesSuresh et al. [66]
Atalantia monophyllaLeafCandida albicans and Aspergillus nigerShowed antimicrobial potential against pathogenic fungiVijayakumar et al. [103]
Trianthema portulacastrumPlantAspergillus niger, Aspergillus flavus and Aspergillus fumigatus0.1Showed significant antifungal propertyKhan et al. [39]
Lycopersicon esculentumLeafCandida albicans0.013A notable reduction in fungal growth was observedVijayakumar et al. [137]
Eucalyptus globulesLeafAlternaria mali, Botryosphaeria dothidea and Diplodia seriataShowed considerable fungicidal property against phytopathogenic fungiAhmad et al. [94]
Citrus sinensisPeelBotrytis cinerea0.2Showed stronger antifungal activity against B. cinereaGao et al. [19]
Beta vulgarisPlantCandida albicans and Aspergillus nigerShown activity against the fungal strainsPillai et al. [25]
Cinnamomum tamala
Cinnamomum verum
Brassica oleracea
* Range of MIC concentration depicts the changes in the concentrations between the test pathogens.
Table 3. Antioxidant activity of plant-mediated zinc oxide nanoparticles.
Table 3. Antioxidant activity of plant-mediated zinc oxide nanoparticles.
Plant NameDescriptionConcentrationMaximum ActivityResultsReference
Polygala tenuifoliaRoot1 mg·mL−145.47%Moderate antioxidant activity by scavenging DPPH free radicalNagajyothi et al. [17]
Cassia fistulaLeaf2853 µg·mL−150%Inhibiting DPPH free radical scavenging activitySuresh et al. [76]
Artocarpus gomezianusFruit10.8 mg·mL−150%Inhibiting DPPH free radical scavenging activitySuresh et al. [77]
Rosa caninaFruit0.2 mg·mL−1>90%DPPH free radical scavenging attributeJafarirad et al. [57]
Azadirachta indicaLeaf8355 μg·mL−192%Inhibiting DPPH free radical scavenging activityMadan et al. [36]
Heritiera fomes and Sonneratia apetalaBark and leaf53.64 μg·mL−150%Strong DPPH free radical scavenging potentialThatoi et al. [16]
Citrullus colocynthisFruit, seed and pulp0.22 mg·mL−1 (Fruit), 0.29 mg·mL−1 (Seed) and 0.26 mg·mL−1 (Pulp)50%Inhibiting DPPH free radical scavenging activityAzizi et al. [80]
Ceropegia candelabrumLeaf95.09 μg·mL−155.43%DPPH free radical scavenging activityMurali et al. [5]
Azadirachta indica, Hibiscus rosa-sinensis, Murraya koenigii, Moringa oleifera and Tamarindus indicaLeaf11.03–31.51 µg·mL−1 (ABTS), 11.49–37.8 µg·mL−1 (DPPH), 23.31–45.9 µg·mL−1 (hydroxyl), 24.4–53.2 µg·mL−1 (superoxide) and 31.4–58.4 µg·mL−1 (hydrogen peroxide)50%Inhibition of ABTS, DPPH, hydroxyl, superoxide and hydrogen peroxide radical scavenging activitiesRehana et al. [22]
Eucalyptus globulusLeaf46.62 μg·mL−182%DPPH free radical scavenging inhibitionSiripireddy and Mandal [83]
Andrographis paniculataLeaf500 μg·mL−161.32%DPPH free radical scavenging inhibitionRajakumar et al. [34]
Mangifera indicaLeaf30 μg·mL−165%DPPH free radical scavenging activityRajeshkumar et al. [65]
Coccinia abyssinicaTuber127.74 μg·mL−150%DPPH free radical scavenging activitySafawo et al. [117]
Kalanchoe pinnataLeaf700 μg·mL−150%Reduce DPPH free radical scavenging capacityAgarwal and Shanmugam [21]
Berberis aristataLeaf3.55 μg·mL−150%DPPH free radical scavenging activityChandra et al. [118]
Trianthema portulacastrumPlant500 μg·mL−175%Efficient DPPH free radical inhibitionKhan et al. [39]
Tecoma castanifoliaLeaf100 μg·mL−167%DPPH free radical scavenging activitySharmila et al. [132]
Scutellaria baicalensisRoot1000 µg·mL−156.11%Scavenging DPPH free radicalsTettey and Shin [70]
Albizia lebbeckStem bark48.5 µg·mL−150%Showed the concentration dependent effect in hydrogen peroxide (H2O2) free radical scavenging activityUmar et al. [26]
Costus igneusLeaf100 μg·mL−175%DPPH free radical scavenging activityVinotha et al. [33]
Sambucus ebulusLeaf43 µg·mL−150%Exhibited hydrogen peroxide (H2O2) free radical scavenging activityAlamdari et al. [124]
Mussaenda frondosaLeaf, stem and leaf-derived callus824 µg·mL−1 (Leaf), 752 µg·mL−1 (Stem) and 857 µg·mL−1 (Callus)50%Quenching the DPPH free radical scavengingJayappa et al. [97]
Aegle marmelosJuice5.75–6.78 mg·mL−1 (DPPH), 4.45–5.05 mg·mL−1 (ABTS) and 7.86–9.05 mg·mL−1 (Superoxide)50%ABTS cation radical, DPPH free radical, and superoxide anion radical scavenging activitiesMallikarjunaswamy et al. [98]
Zea mays, Artocarpus heterophyllus and Punica granatumHusk (Z. mays) and peel (A. heterophyllus and P. granatum)395.2 µg·mL−1 (P. granatum)50%Inhibitory of DPPH radical scavengerQuek et al. [31]
Myristica fragransFruit400 μg·mL−182.12 TEAC (ABTS); 66.3% FRSA (DPPH); 71.1 μg AAE/mg (TAC); 63.41 μg AAE/mg (TRP)Excellent free radical scavenging activities (ABTS, DPPH, TAC and TRP)Faisal et al. [11]
Note: ABTS—2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, DPPH—2,2-diphenyl-1-picrylhydrazyl, TAC—total antioxidant capacity, TRP—total reduction power, and FRSA—free radical scavenging assay.
Table 4. Antidiabetic activity of plant-mediated zinc oxide nanoparticles.
Table 4. Antidiabetic activity of plant-mediated zinc oxide nanoparticles.
Plant NameDescriptionConcentrationActivity (IC50Value) *
(mg mL−1)
ResultsReference
Hibiscus subdariffaLeaf8 mg·kg−1 of body weightStreptozotocin (STZ: 100 mg/kg of body weight) induced diabetes was cured by intraperitoneal injection of zinc oxide in miceBala et al. [35]
Heritiera fomes (HF)and Sonneratia apetala (SA)Bark and leaf100 μL0.33 (HF) and 0.39 (SA)Exhibited better anti-diabetic activity in terms of α-amylase inhibition activityThatoi et al. [16]
Azadirachta indica, Hibiscus rosa-sinensis, Murraya koenigii, Moringa oleifera and Tamarindus indicaLeaf100–1.52 µg·mL−1α-amylase: 0.025–0.05
α-glucosidase: 0.012–0.05
Exhibited higher α-amylase and α-glucosidase inhibition activityRehana et al. [22]
Vaccinium arctostaphylosFruitExhibited great treating efficacy on alloxan-diabetic rats compared to chemically synthesized zinc oxideBayrami et al. [63]
Andrographis paniculataLeaf100 μL0.12Exhibited better anti-diabetic activity in terms of exhibiting moderate α-amylase inhibitory activityRajakumar et al. [34]
Costus igneusLeaf100 μg·mL−1Increased the percentage of α-amylase and α-glucosidase inhibition with increased concentration of nanoparticlesVinotha et al. [33]
Mussaenda frondosaLeaf, stem and leaf-derived callus20 μLα-amylase: 0.014- 0.055
α-glucosidase: 0.014–0.035
Exhibited on par α-amylase inhibitory activity and α-glucosidase inhibitory activityJayappa et al. [97]
Myristica fragransFruit400 μg·mL−1Excellent α-amylase and α-glucosidase inhibition activityFaisal et al. [11]
* Range of the IC50 value depicts the changes in between the methods employed.
Table 5. Anticancer activity of plant-mediated zinc oxide nanoparticles.
Table 5. Anticancer activity of plant-mediated zinc oxide nanoparticles.
Plant NameDescriptionCell Lines UsedActivity
(IC50Value)
ResultsReference
Anchusa italicaFlowerVero cells142 μg·mL−1Showed concentration-dependent cytotoxicity on the growth of Vero cellsAzizi et al. [6]
Rosa caninaFruitAlveolar adenocarcinoma (A549) cells>0.1 mg·mL−1Exhibited dose-dependent toxicity to A549 cellsJafarirad et al. [57]
Citrullus colocynthisFruit, seed and pulp3T3 cells0.258 mg·mL−1 (Fruit), 0.160 mg·mL−1 (Seed) and 0.210 mg·mL−1 (Pulp)Showed a dose dependent toxicity on the growth of 3T3 cells with non-toxic effect of concentration below 0.26 mg/mLAzizi et al. [80]
Pongamia pinnataSeedHuman MCF-7 breast cancer cell lines50 μg·mL−1More successful in control of human MCF-7 breast cancer cells compared to the seed extract and bulk zinc oxide (positive control)Malaikozhundan et al. [111]
Ziziphus nummulariaLeafHeLa cancer cell lines50 and 200  μg·mL−1Showed potent dose-dependent cytotoxic effect against HeLa cancer cell linesPadalia and Chanda [7]
Mangifera indicaLeafLung cancer A549 cell lines25 μg·mL−1Significant cytotoxic effect against lung cancer A549 cell linesRajeshkumar et al. [65]
Costus pictusLeafDaltons lymphoma ascites (DLA) cells50 µg·mL−1Exhibited strong anticancer behavior against DLA bearing mice cell linesSuresh et al. [66]
Anacardium occidentaleLeafHuman normal fibroblast cell line (Hu02) and human pancreatic cancer cell lines (Panc-1 and AsPC-1)40 μM (Panc-1) and 30 μM (AsPC-1)Exhibited the concentration-dependent cytotoxicity against human pancreatic cancer cell linesZhao et al. [88]
Kalanchoe pinnataLeafMurine macrophage RAW 264.7 cellsExhibited no significant cytotoxicity up to 1 mg/mL in RAW 264.7 cellsAgarwal and Shanmugam [21]
Gracilaria edulisAqueous extractCervical carcinoma cells (SiHa cells)35 μg·mL−1Exhibited cytotoxic effect against SiHa cells in a dose dependent mannerAsik et al. [89]
Juglans regiaLeafHuman skin fibroblasts200 μg·mL−1Have less cytotoxicity than chemical zinc oxide nanoparticlesDarvishi et al. [119]
Cucurbita pepoLeafMammalian osteoblast-like MG63 cells20 ppmInduced cytotoxicity that affected the proliferation of MG63 cells in the concentration dependent mannerHu et al. [120]
Pandanus odoriferLeafBreast cancer (MCF-7), liver cancer (HepG2), and lung cancer (A-549) cells100 μg·mL−1Apoptotic and necrosis effect on MCF-7, HepG2, and A549 cancer cell linesHussain et al. [121]
Trianthema portulacastrumPlantMouse pre-osteoblast cell line (MC3T3-E1)Showed no toxic effect and the cells were found viableKhan et al. [39]
Cucumis melo inodorusRough shellHuman (Michigan Cancer Foundation-7 [MCF7]) and murine (TUBO) breast cancer cell lines40 µg·mL−1 (MCF7);
20 µg·mL−1 (TUBO)
Found as a powerful apoptosis inducer in breast cancer cells in human cell line (MCF7) and murine (TUBO cell line and cancer model)Mahdizadeh et al. [101]
Artocarpus heterophyllusLeafHuman colon cancer HCT-116 cell lines20 μg·mL−1Showed excellent cytotoxic effect against human colon cancer HCT-116 cell linesMajeed et al. [93]
Hyssops officinalisPlantMDA-MB231 breast cancer cell line125 μg·mL−1Inhibitory effects on the growth of breast cancer cells and induction of cytotoxicity depending on nanoparticle concentration and time of exposureRahimi Kalateh Shah Mohammad et al. [102]
Annona squamosaLeafCervical cancer cells (HeLa cell lines)50 μg·mL−1Anticancer activity against HeLa cell lines in a dose dependent pattern with a defensive prospect towards mammalian (HEK-293) cellsRuddaraju et al. [69]
Tecoma castanifoliaLeafHuman lung carcinoma cells (A549)65 μg·mL−1Conferred better cytotoxic effects on proliferation of A549 cell lineSharmila et al. [132]
Scutellaria baicalensisRootHeLa cells (Human cervical cancer cell line) and RAW 264.7 murine macrophage cells1000 µg·mL−1Showed dose-dependent antiproliferative activity against the growth of HeLa cells and no toxicity on RAW 264.7 macrophages (normal immune system cells)Tettey and Shin [70]
Albizia lebbeckStem barkHuman breast cancer cell lines (MDA-MB 231 and MCF-7)Cytotoxicity:
100 µg·mL−1 (MDA-MB 231) and 5 µg·mL−1 (MCF-7); Proliferation:
100 µg·mL−1 (MDA-MB 231 and MCF-7)
Inhibited the cell viability and cell number (proliferation) of MDA-MB 231 and MCF-7 cells in concentration dependent mannerUmar et al. [26]
Lycopersicon esculentumLeafMurine macrophage cells (RAW 264.7) and Human cervical cancer (HeLa) cells100 µg·mL−1Zinc oxide nanoparticles were non-toxic to macrophage cells, as no alterations in viability. Treatment of HeLa cells with zinc oxide nanoparticles induced cell growth retardation, cell clumping, cell bursting, and loss of membrane stability and they prevented the proliferation of HeLa cellsVijayakumar et al. [137]
Rehmanniae radixPlantBone cancer cell line MG-6330 μg·mL−1Exhibited strong anticancer activity and inducing apoptosis on MG-63 cells via stimulating increased generation of ROSCheng et al. [104]
Citrus sinensisPeelHuman umbilical vein endothelial cells (HUVECs)Below 25 mg·L−1Cytotoxicity towards HUVECs exhibited when the concentration exceeded 12.5 mg L−1Gao et al. [19]
Mussaenda frondosaLeaf, stem and leaf-derived callusHuman lung adenocarcinoma cells (A549)67.75 µg·mL−1 (Callus) and 85.66 µg·mL−1 (Stem)Exhibited on par cytotoxic activity on A549 cells in a dose-dependent actionJayappa et al. [97]
Hyssopus officinalisLeafHuman prostate cancer (PC3) cells8.07 µg·mL−1 (24 h) and 5 µg·mL−1 (48 h)Demonstrated the dose-dependent cytotoxicity effect and induced apoptosis on PC3 cellsRahimi Kalateh Shah Mohammad et al. [107]
Crotalaria verrucosaLeafHeLa and DU145 cell lines7.07 µg·mL−1 (HeLa); 6.30 µg·mL−1 (DU145)Exhibited the dose-dependent inhibition curve with IC50 value of 7.07 µg/mL and 6.30 µg/mL in HeLa and DU145 cells, respectivelySana et al. [71]
Deverra tortuosaPlantHuman colorectal epithelial adenocarcinoma (Caco-2), human lung epithelial carcinoma (A549) and normal human lung fibroblast cell line (WI38)83.47 μg·mL−1 (A549), 50.81 μg·mL−1 (Caco-2) and 434.60 μg·mL−1 (WI38)Exhibited the profound selective concentration dependent cytotoxic effect on Caco-2 and A549 cancer cell lines with appreciable lower cytotoxic activity on normal WI38 cellsSelim et al. [99]
Euphorbia fischerianaRootLung cancer (A549) cells14.5 µg·mL−1Induced cytotoxicity and also activated apoptosis during increased ROS formation, decreased mitochondrial membrane potential, inhibited cell migration, altered AO/EtBr staining and induced pro-apoptotic and inhibited anti-apoptotic proteinZhang et al. [129]
Myristica fragransFruitStreptomyces 85E strain for protein kinase inhibition capability5 mg·mL−1Clear zones were observed against Streptomyces 85E strain which used to elucidate the protein kinase inhibition capabilityFaisal et al. [11]
Raphanus sativusLeafLung cancer cell line (A549)40 μg·mL−1Showed a better anticancer activity by reducing cell viabilityUmamaheswari et al. [29]
Table 6. Anti-inflammatory activity of plant-mediated green synthesized zinc oxide nanoparticles.
Table 6. Anti-inflammatory activity of plant-mediated green synthesized zinc oxide nanoparticles.
Plant NameDescriptionAssay/ModelActivity
(IC50Value)
ResultsReference
Polygala tenuifoliaRootLPS-stimulated RAW 264.7 murine macrophage cells1 mg·mL−1Showed anti-inflammatory activity by suppressing the LPS-induced mRNA and protein expressions of iNOS, COX-2, and anti-inflammatory cytokines in LPS-stimulated RAW 264.7 murine macrophage cellsNagajyothi et al. [17]
Heritiera fomes (HF) and Sonneratia apetala (SA)Bark and leafInhibition of protein denaturationin vitroassay72.35 μg·mL−1 (HF) and 63.29 μg·mL−1 (SA)Anti-inflammation activity inhibiting protein (heat induced albumin) denaturationThatoi et al. [16]
Andrographis paniculataLeafInhibition of protein denaturationin vitroassay66.78 μg·mL−1Anti-inflammatory activity by inhibiting protein denaturationRajakumar et al. [34]
Kalanchoe pinnataLeafLPS-induced Murine Raw 264.7 cell lines; Detection of the mRNA expressions of TNF-α, IL-1β, IL-6, and COX-2Reduced the expression of pro-inflammatory cytokines, attenuated the release of IL-1β, IL-6, and TNF-α by inhibiting mRNA expression, inhibited the gene expression of COX-2 enzyme and suppressed NO productionAgarwal and Shanmugam [21]
Hyssops officinalisPlantReduction of mouse paw edema5 mg·kg−1Reduction of inflammation by significantly reducing the thickness of mouse paw edemaMohammad et al. [102]
Mussaenda frondosaLeaf, stem & leaf-derived callusHuman red blood cells membrane stabilization method500 µg·mL−1Exhibited varying degrees of human RBCs membrane and lysosomal membrane stabilizing activity in a dose-dependent mannerJayappa et al. [97]
Vernonia amygdalinaLeafSwiss Albino male mice2.5, 5, and 7.5 mg·kg−1Exhibited the potent anti-inflammatory activity against carrageenan induced-inflammation in miceLiu et al. [125]
Table 7. Photocatalytic activity of the plant-mediated zinc oxide nanoparticles.
Table 7. Photocatalytic activity of the plant-mediated zinc oxide nanoparticles.
Plant NameDye DegradedSolar Irradiation TimepH RangeDegradation Efficiency (%)Reference
Phyllanthus niruriMethylene blue (MB)30 min99%Anbuvannan et al. [53]
Anisochilus carnosusMethylene blue (MB)90 min100%Anbuvannan et al. [54]
Vitex trifoliaMethylene blue (MB)90 min92.13%Elumalai et al. [72]
Plectranthus amboinicusMethyl red (MR)180 min92.45%Fu and Fu [73]
Allium sativum, Allium cepa and Petroselinum crispumMethylene blue180 min>90%Stan et al. [74]
Cassia fistulaMethylene blue120 min790% (for 5 ppm)Suresh et al. [76]
Artocarpus gomezianusMethylene blue (MB)120 min10100% (for 5 ppm, sun light); 65% (for 5 ppm, UV light)Suresh et al. [77]
Corymbia citriodoraMethylene blue90 min83.45%Zheng et al. [78]
Mimosa pudicaMethylene blue120 min90%Fatimah et al. [110]
Coffea arabicaMethylene blue120 min98%
Carissa edulisCongo red130 min97%Fowsiya et al. [56]
Nephelium lappaceumMethyl orange (MO)120 min7.0183.99%Karnan and Selvakumar [58]
Azadirachta indicaMethylene blue (MB)120 min>80%Madan et al. [36]
Terminalia chebulaRhodamine B (RhB)5 h70% (for 5 ppm)Rana et al. [79]
Carica papayaAlizarin Red-S120 min99%Sharma [60]
Sedum alfredii2-chlorophenol (2-CP)120 min6.396.93%Wang et al. [133]
Camellia sinensisMethylene blue (MB)240 min100%Nava et al. [62]
Eucalyptus globulusMethylene blue (MB) and Methyl orange (MO)50 min (MB) and 1 h (MO)98.2% (MB) and 96.6% (MO)Siripireddy and Mandal [83]
Acacia senegalDirect blue 129 (DB129)105 min95%Taghavi Fardood et al. [84]
Conyza canadensisMethylene blue (MB) and Methyl orange (MO)45 min (MO) and 20 min (MB)94.5% (MO) and 85.3% (MB)Ali et al. [85]
Garcinia mangostanaMalachite green180 min99%Aminuzzaman et al. [86]
Citrus sinensisMethylene blue (MB)120 min83%Luque et al. [64]
Ferulago angulataRhodamine B (RhB)150 min93%Mehr et al. [115]
Laurus nobilisRemazol Brilliant Red F3B (Reactive Red 180, RR180)45 minAround 6.899%Chemingui et al. [92]
Dolichos lablabMethylene blue (MB), Rhodamine B (RhB) and Orange II (OII)210 min11 (MB), 9 (RhB) and 5 (OII)80% (MB), 95% (RhB), and 66% (OII)Kahsay et al. [122]
Trianthema portulacastrumSynozol navy blue K-BF150min91%Khan et al. [39]
Abelmoschus esculentusMethylene blue (MB) and Rhodamine B (RhB)60 min (MB) and 50 min (RhB)∼7100%Prasad et al. [123]
Artabotrys hexapetalu (AH) and
Bambusa vulgaris (BV)
Rhodamine B (RhB)180 minNeutral92% (AH) and 88% (BV)Shanavas et al. [68]
Musa acuminataMethylene blue (MB)7 h1298.13%Abdullah et al. [40]
Sambucus ebulusMethylene blue200 min80%Alamdari et al. [124]
Ziziphus jujubaMethylene blue (MB) and Eriochrome black-T (ECBT)5 h92% (MB) and 86% (ECBT)Golmohammadi et al. [96]
Mussaenda frondosaMethylene blue100 min (Leaf), 100 min (Stem), and 120 min (Callus)730% (Leaf), 30% (Stem) and 90% (Callus)Jayappa et al. [97]
Aegle marmelosMethylene blue (MB)35 min96%Mallikarjunaswamy et al. [98]
QuinceMethylene blue2 hNormal80%Moghaddas et al. [141]
Syzygium cuminiRhodamine B (RhB)100 min998%Rafique et al. [106]
Aloe veraMethyl orange (MO)140–160 min95%Sharma et al. [127]
Thlaspi arvenseMethylene blue (MB)2 h100%Ullah et al. [108]
Calliandra haematocephalaMethylene blue (MB)270 min88%Vinayagam et al. [128]
Myristica fragransMethylene blue140 min88%Faisal et al. [11]
Bridelia retusaRhodamine B165 minUpto 94.74%Vinayagam et al. [130]
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Murali, M.; Kalegowda, N.; Gowtham, H.G.; Ansari, M.A.; Alomary, M.N.; Alghamdi, S.; Shilpa, N.; Singh, S.B.; Thriveni, M.C.; Aiyaz, M.; et al. Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications. Pharmaceutics 2021, 13, 1662. https://doi.org/10.3390/pharmaceutics13101662

AMA Style

Murali M, Kalegowda N, Gowtham HG, Ansari MA, Alomary MN, Alghamdi S, Shilpa N, Singh SB, Thriveni MC, Aiyaz M, et al. Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications. Pharmaceutics. 2021; 13(10):1662. https://doi.org/10.3390/pharmaceutics13101662

Chicago/Turabian Style

Murali, Mahadevamurthy, Nataraj Kalegowda, Hittanahallikoppal G. Gowtham, Mohammad Azam Ansari, Mohammad N. Alomary, Saad Alghamdi, Natarajamurthy Shilpa, Sudarshana B. Singh, M. C. Thriveni, Mohammed Aiyaz, and et al. 2021. "Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications" Pharmaceutics 13, no. 10: 1662. https://doi.org/10.3390/pharmaceutics13101662

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