Search Results (86)

Background/objectives: Schistosomiasis is a parasitic disease that represents a serious public health problem. An alternative for the control of snails, intermediate hosts of schistosomiasis, is the use of molluskicides. Niclosamide, recommended by the WHO, has limitations, such as environmental toxicity, which has driven the search for safer and biodegradable alternatives, especially of plant origin. In this context, this study investigated the biological activity of Cymbopogon winterianus essential oil on embryos, juveniles, and adults of Biomphalaria glabrata and cercariae of Schistosoma mansoni. Methods: Essential oils (EOs) were extracted from fresh leaves via the Clevenger system and characterized via gas chromatography (GC/MS and GC/FID), revealing geraniol (25.0%), citronellal (29.2%), citronellol (10.5%) and elemol (9.6%) as the main components. Results: The results revealed lethal concentrations 90 (LC₉₀) for young and adult snails of 60.72 mg/L, 74.21 mg/L and 115.35 mg/L, respectively. In the histological analysis, no changes were observed in the tissues of the mollusks exposed to the lethal concentration 25 (LC₂₅). However, the lethal concentrations 50 (LC₅₀) and 75 (LC₇₅) caused crystalline concretions in proximity to the renal saccular portion. At a concentration of 60 mg/L, the oil resulted in 100% lethality in embryos and cercaricidal activity greater than 90% in 3 h. Acute toxicity tests in mice via the intraperitoneal or oral route did not reveal toxic effects, with hematological and biochemical parameters within the reference values. Furthermore, the oil did not inhibit acetylcholinesterase (AChE), indicating low toxicity to fish, and caused a slight reduction in human butyrylcholinesterase (hBChE) activity without affecting human AChE, which suggests low toxicity to mammalian tissues. In terms of environmental impact, the oil was not toxic to algae until the 75th day, with mortality observed thereafter. Conclusions: These results indicate that essential oils have great potential as biodegradable and safe alternatives for controlling mollusks and interrupting the schistosomiasis cycle. Full article

The rising incidence of vulvovaginal candidiasis (VVC) has been leading to the development of alternative antifungal therapies. This study aimed to develop a topical chitosan–oleic acid nanoparticle (CH-OA-NP) cream loaded with lemon peel essential oil (LPEO) for VVC treatment. The characterization of the optimal nanoparticle formulation (F4: 10 g/L CH, 2:1 OA/LPEO ratio) showed high encapsulation efficiency, stability, and controlled release. Moreover, it was characterized regarding its particle size, polydispersity index, zeta potential, and chemical/morphological profile. LPEO-related compounds (e.g., eriodictyol) were identified through LC-ESI-QqTOF-HRMS in the cream matrix, suggesting the preservation of LPEO potential bioactivities after formulation. In silico docking of 12 LPEO metabolites revealed that compounds such as citronellic acid exerted inhibitory effects against several inflammation-associated enzymes (e.g., 14-α-Demethylase). In vitro antimicrobial tests demonstrated remarkable activity against Candida albicans, Gram-negative (e.g., Escherichia coli), and Gram-positive (e.g., Staphylococcus aureus) bacteria. In vivo studies in a rat model of VVC revealed significant antifungal, anti-inflammatory, and immunomodulatory effects of the LPEO-CH-OA-NP cream (5% and 10%), leading to reduced MDA, MPO, and IL-1β levels and increased GSH activity. This novel formulation potentially offers a promising alternative therapy for VVC, addressing the current antifungal therapies’ limitations, counteracting drug resistance. Full article

This study aimed to analyze the potential of phytochemicals linalool and citronellal against E. coli and S. aureus biofilms and to compare the results to sodium hypochlorite. We tested the minimal inhibitory concentration, bacterial cell reduction, respiratory chain dehydrogenase activity, cell membrane integrity, and biomass reduction. The results show the lowest inhibitory concentration for both E. coli and S. aureus for sodium hypochlorite, followed by a combination of linalool and citronellal, the sole use of linalool, and the sole use of citronellal, respectively. Furthermore, we found that linalool was effective in biofilm cell reduction, cell respiratory inhibition, membrane integrity, and biomass reduction, while citronellal was less effective. Overall, this indicates that linalool has some benefits in biofilm management, especially with a focus on reducing toxic sodium hypochlorite consumption. Full article

Citrus depressa Hayata is a citrus cultivar grown in Japan and Taiwan. To assess the differences in genetic characteristics and volatile organic components (VOCs) in the leaves and edible parts of the fruits of 23 C. depressa accessions from different geographic origins, the tissues were analyzed using cleaved amplified polymorphic sequence markers and gas chromatography-mass spectrometry. A phylogenetic cluster analysis demonstrated that Kagoshima accessions had a close genetic relationship with one another, with Okinawan “Izumi kugani-like” being the most distinct accession. The predominant volatiles in the leaves were γ-terpinene, p-cymene, limonene, and linalool. Multivariate analysis and volcano plots revealed distinct volatiles in the leaves of each cultivation region: piperitone and citronellal (Kagoshima); 5,9,9-trimethyl-spiro[3.5]non-5-en-1-one (Okinawa); and hexanal (Taiwan). Furthermore, the edible parts of Taiwanese fruits contained abundant amounts of monoterpenes, including linalool and 1,8-cineole. In contrast, Kagoshima and Okinawa accessions were rich in aldehydes and esters, respectively. In conclusion, the genetic and volatile profiles of 23 C. depressa accessions of different origins could be distinguished, and multivariate analysis suggested that C. depressa contains diverse VOCs depending on where it is cultivated. These findings demonstrate the exclusivity of C. depressa resources in each region, which could assist farmers and agro-industries in promoting food products derived from C. depressa fruits. Full article

The house fly is a significant pest in agriculture and human health that is increasingly difficult to manage due to multiple limitations including resistance development. To explore alternative pesticides, the topical toxicity and repellency profiles of 17 essential oil components (EOCs) were evaluated against a resistant and a susceptible strain of house fly, Musca domestica L., using topical application and Y-tube olfactometers, respectively. Six of the most toxic EOCs based on the LD₅₀ were further investigated against a susceptible strain of house fly. Thymol, (+)-pulegone, eugenol, and carvacrol were always the top four most toxic chemicals tested against the resistant house fly strain. Little to no resistance was observed to the top six EOCs based on the comparison of the results between resistant and susceptible house fly strains. P-Cymene, citronellic acid, R-(+)-limonene, linalool, γ-terpinene, estragole, and eugenol were repellent to adult house flies at certain concentrations while (-)-carvone and thymol were attractive to adult house flies. This screening of a wide variety of individual EOCs provides a stronger foundation of information for further research. This should encourage further investigation into the topical toxicity and repellency in field studies, which will provide more insight into the performance of biopesticides for house fly management and potential commercialization. Full article

Green huajiao has a unique flavor and is widely used in cooking as an edible spice. In this study, the intensity of overall aroma and aroma attributes of seven green huajiao samples from the Sichuan and Chongqing regions were evaluated using a dynamic dilution olfactometer and ranking descriptive analysis (RDA) technology. The volatile compounds and major aroma components were determined by GC-MS in combination with odor activity value (OAV) analysis. The partial least squares regression (PLSR) model was further used to identify the key aromas contributing to the aroma sensory attributes. Seven green huajiao samples were categorized into three groups: (1) huajiao samples from Liangshan have a strong intensity of pungent, floral and herbal aromas and a medium-high intensity of sweet aroma, and the key contributing aroma compounds were α-pinene, sabinene, β-pinene, myrcene, ocimene and linalool; (2) huajiao samples from Panzhihua and Hongya have a strong intensity of citrusy, lemony and minty aromas, and the key contributing aroma compound was linalool; and (3) the huajiao sample from the Chongqing region was categorized into a separate group and was characterized by a medium-high intensity of green, minty and sweet aromas, and the main aroma compounds are ocimene, citronellal and α-terpineol. These results provide useful basic data for evaluating the aroma quality and analyzing the key aroma characteristics of green huajiao in the Sichuan and Chongqing regions. Full article

Selective enhancement of wine aroma was achieved using a broad spectrum of exogenous glycosidases. Eight different enzyme preparations were added to Verdejo wine, resulting in an increase in the levels of varietal volatile compounds compared to the control wine after 15 days of treatment. The enzyme preparations studied were robust under winemaking conditions (sulfur dioxide, reducing sugars, and alcohol content), and no inhibition of β-glucosidase activity was observed. Significant differences were detected in four individual terpenes (α-terpineol, terpinen-4-ol, α-pinene, and citronellal) and benzyl alcohol in all the treated wines compared to the control wine, contributing to the final wine to varying degrees. In addition, a significant increase in the other aromatic compounds was observed, which showed different patterns depending on the enzyme preparation that was tested. The principal component analysis of the data revealed the possibility of modulating the different aromatic profiles of the final wines depending on the enzyme preparation used. Taking these results into account, enhancement of the floral, balsamic, and/or fruity notes of wines is possible by using a suitable commercial enzyme preparation. Full article

Litsea cubeba (Lour.) Pers. is an important economic tree. We aimed to explore the phenotypic diversity of wild L. cubeba provenances from Jiangxi province and identify the germplasms with desirable characteristics. Nest variance analysis, multiple comparisons, correlation analysis, path analysis, redundancy analysis, and cluster analysis were conducted to compare the phenotypes of 526 wild L. cubeba trees from 27 provenances. We detected significant differences in the growth traits, fruit traits, and essential oil (EO) content of L. cubeba provenances, as well as significant differences in tree height, thousand seed dry weight, and the proportion of five essential oil components (citral, neral, geranial, D-limonene, and citronellal) within the provenances. The fresh fruit yield (FFY) was mainly determined by the ground diameter and the annual average minimum temperature. The EO content was mainly affected by the water content, annual average temperature, longitude, and latitude. The proportion of citral (CitrP) was negatively affected by extreme low temperatures. Four individual L. cubeba trees had a high FFY of over 10.00 kg·tree⁻¹. Two trees had a high EO content exceeding 5%, with their CitrP over 80%. The provenances with high FFY were Guixi and Yushan (2.65 kg·tree⁻¹; 2.89 kg·tree⁻¹). The provenances with a high EO content of about 4.00% were Dayu, Yudu, Ji’an, Xinfeng, and Yushan. The provenance with the highest CitrP level (80.61%) was Ningdu. Full article

One of the primary therapeutic approaches for managing Alzheimer’s disease (AD) involves the modulation of Acetylcholine esterase (AChE) activity to elevate acetylcholine (ACh) levels inside the brain. The current study employed computational chemistry approaches to evaluate the inhibitory effects of CTN on AChE. The docking results showed that Citronellal (CTN) and standard Donepezil (DON) have a binding affinity of −6.5 and −9.2 Kcal/mol, respectively, towards AChE. Further studies using molecular dynamics (MD) simulations were carried out on these two compounds. Binding free energy calculations and ligand-protein binding patterns suggested that CTN has a binding affinity of −12.2078. In contrast, DON has a much stronger binding relationship of −47.9969, indicating that the standard DON has a much higher binding affinity than CTN for AChE. In an in vivo study, Alzheimer-type dementia was induced in mice by scopolamine (1.5 mg/kg/day i.p) for 14 days. CTN was administered (25 and 50 mg/kg. i.p) along with scopolamine (SCO) administration. DON (0.5 mg/kg orally) was used as a reference drug. CTN administration significantly improved the mice’s behavior as evaluated by the Morris water maze test, evident from decreased escape latency to 65.4%, and in the CPS test, apparent from reduced escape latency to 69.8% compared to the positive control mice. Moreover, CTN significantly increased the activities of antioxidant enzymes such as catalase and superoxide dismutase (SOD) compared to SCO. Furthermore, CTN administration significantly decreased SCO-induced elevated AChE levels in mice. These results were supported by histopathological and in silico molecular docking studies. CTN may be a potential antioxidant and neuroprotective supplement. Full article

Amblyomma sculptum is a relevant tick species from a One Health perspective, playing an important role as a vector of Rickettsia rickettsii, the main agent of spotted fever rickettsiosis in Brazil. In this study, we evaluated the susceptibility of two A. sculptum populations from Goiás state (midwestern Brazil) to different acaricides. The first tick population (GYN strain) originated from an experimental farm, where the ticks are annually exposed to acaricides. The second (PNE strain) was collected in a national park (Emas National Park), where the ticks had not been exposed to acaricides. Immersion tests were conducted with 21-day-old laboratory-reared larvae and nymphs originating from adult ticks collected in the areas mentioned above. The chosen acaricides were two synthetic pyrethroids (cypermethrin and deltamethrin), one organophosphate (chlorfenvinphos), one formamidine (amitraz), and two combinations of pyrethroids and organophosphates (cypermethrin, chlorpyrifos and citronellal; cypermethrin, fenthion and chlorpyrifos). Mortality data were used to determine the lethal concentration (LC) values at which 50%, 90%, and 99% of the ticks died (LC₅₀, LC₉₀, and LC₉₉, respectively), and resistance ratios (RR) were calculated based on the LC values. The RR revealed differences between the acaricide-exposed (GYN) and unexposed (PNE) tick strains. The PNE strain larvae and nymphs were susceptible to all the tested acaricides. The GYN strain larvae were tolerant to cypermethrin, whereas the nymphs were tolerant to deltamethrin, chlorfenvinphos, and the combination of cypermethrin, chlorpyrifos, and citronellal (2 < RR ≤ 10). The GYN strain nymphs were resistant to amitraz (RR > 10). This is the first report of A. sculptum nymphs with resistance to amitraz and tolerance to deltamethrin, chlorfenvinphos, and the combination of cypermethrin, chlorpyrifos, and citronellal. Full article

The insertion of circular economy principles into the essential oil (EO) production chain aims to reduce waste generation and make integral use of harvested plant material. Higher profits from integral use with reduced waste generation contribute to the eventual use of the EO value chain as an alternative to illicit crops in Colombia (mostly coca). In this study, Java-type citronella (Cymbopogon winterianus) and palmarosa (C. martinii) plant materials were used in two consecutive processes to obtain EOs and extracts. The residual biomass after EO distillation was subjected to ultrasound-assisted hydroethanolic extraction to afford extracts that contained bioactive compounds. Citronella and palmarosa were distilled with typical EO yields (1.0 ± 0.1% for citronella; 0.41 ± 0.06% for palmarosa; n = 5) either through hydrodistillation assisted by microwave radiation or through steam distillation, and their composition (determined via GC/FID/MS analysis) and physicochemical parameters fell within their ISO standard specifications. The concentration of citronellal, the major compound of citronella oil, was 500 ± 152 mg/g. Geraniol, the main component of palmarosa oil, was found at 900 ± 55 mg/g. The citronella and palmarosa hydroalcoholic extracts (4–11% yield) were analyzed with UHPLC-ESI-Orbitrap-MS, which permitted the identification of 30 compounds, mainly C-glycosylated flavones and hydroxycinnamic acids. Both extracts had similar antioxidant activity values, evaluated using the ABTS^+● and ORAC assays (110 ± 44 µmol Trolox^®/g extract and 1300 ± 141 µmol Trolox^®/g extract, respectively). Full article

This study aimed to evaluate the extraction of Corymbia citriodora (Hook.) K.D.Hill and L.A.S.Johnson essential oil by steam distillation under reduced pressure. Yield and composition of the essential oils obtained at different system pressures were analyzed. System pressure had a significant influence on essential oil yield, resulting in a reduction of 78.6% when the pressure was reduced from 690 Torr to 240 Torr. There were also changes in essential oil composition, with an increase in citronellol content (oxygenated monoterpene). However, the major compound (citronellal) remained at a high content in all tests. Regarding the extracted mass of the major compounds (citronellal, citronellol), there was a significant reduction for all when the system pressure was reduced. Although the reduction in the pressure of the system caused a reduction in oil yield, it was possible to carry out the steps of extraction and purification of the major compound simultaneously. Reduced pressure extraction may decrease process time, increasing its efficiency and reducing costs in the extraction of essential oils. Full article

Climate change is prompting a shift of tropical pests to locations with a previously lower probability of invasion. This is the case for root-knot nematodes, Meloidogyne sp., particularly of the tropical group. Among them, M. ethiopica is now considered a threat to European food security. The development of novel sustainable nematicides can be based on in vitro bioassays of highly active phytochemicals, e.g., volatiles from essential oils. However, a steady supply of nematodes is often very difficult and dependent on environmental conditions. In the present study, an in vitro co-culture system of M. ethiopica parasitizing hairy roots of Solanum lycopersicum was established, for the first time, to easily obtain populations of second-stage juveniles (J2). These were then used to screen the nematicidal activity of 10 volatile compounds characteristic of essential oils. Finally, information on the most successful compounds was reviewed to predict their environmental dispersion and ecotoxicological hazards. The M. ethiopica population obtained from the co-culture was morphologically similar to reported populations in natural conditions and could be accurately used in direct-contact bioassays. The aldehydes citral and citronellal induced complete mortality of the tested J2, at 1 mg/mL, while compounds from other chemical groups were not as successful. In comparison to commonly used commercial nematicides, citral and citronellal were less likely to accumulate in the water environmental compartment and have lower reported toxicities compared to aquatic organisms and to mammals. Overall, in vitro co-cultures showed the potential to expedite the screening and discovery of bioactive compounds as a contribution to the development of sustainable biopesticides, as well as to lower the impacts of modern farming on agroecosystems. Full article

Medicinal plant extracts are a promising source of bioactive minor contents. The present study aimed to evaluate the distinguished volatile content of Algerian Cymbopogon citratus (DC.) Stapf before and after the microfluidization process and their related antimicrobial and anti-mycotoxigenic impacts and changes. The GC-MS apparatus was utilized for a comparative examination of Algerian lemongrass essential oil (LGEO) with its microfluidization nanoemulsion (MF-LGEO) volatile content. The MF-LGEO was characterized using Zetasizer and an electron microscope. Cytotoxicity, antibacterial, and antifungal activities were determined for the LGEO and MF-LGEO. The result reflected changes in the content of volatiles for the MF-LGEO. The microfluidizing process enhanced the presence of compounds known for their exceptional antifungal and antibacterial properties in MF-LGEO, namely, neral, geranial, and carvacrol. However, certain terpenes, such as camphor and citronellal, were absent, while decanal, not found in the raw LGEO, was detected. The droplet diameter was 20.76 ± 0.36 nm, and the polydispersity index (PDI) was 0.179 ± 0.03. In cytotoxicity studies, LGEO showed higher activity against the HepG2 cell line than MF-LGEO. Antibacterial LGEO activity against Gram-positive bacteria recorded an inhibitory zone from 41.82 ± 2.84 mm to 58.74 ± 2.64 mm, while the zone ranged from 12.71 ± 1.38 mm to 16.54 ± 1.42 mm for Gram-negative bacteria. Antibacterial activity was enhanced to be up to 71.43 ± 2.54 nm and 31.54 ± 1.01 nm for MF-LGEO impact against Gram-positive and Gram-negative pathogens. The antifungal effect was considerable, particularly against Fusarium fungi. It reached 17.56 ± 1.01 mm and 13.04 ± 1.37 mm for LGEO and MF-LGEO application of a well-diffusion assay, respectively. The MF-LGEO was more promising in reducing mycotoxin production in simulated fungal growth media due to the changes linked to essential compounds content. The reduction ratio was 54.3% and 74.57% for total aflatoxins (AFs) and ochratoxin A (OCA) contents, respectively. These results reflect the microfluidizing improvement impact regarding the LGEO antibacterial, antifungal and anti-mycotoxigenic properties. Full article

The essential oil extracted from Melissa officinalis (MOEO) exhibits a wide range of therapeutic properties, including antioxidant, antibacterial, and antifungal activities. The current research aimed to analyze the mechanical, barrier, chemical, and antioxidant properties of pectin and collagen-based films. Hydrogel-based films loaded with varying concentrations of MOEO (0.1%, 0.15%, and 0.2%) were prepared by solvent-casting method, and their physicochemical as well as antioxidant properties were examined. GC-MS analysis revealed the presence of major components in MOEO such as 2,6-octadienal, 3,7-dimethyl, citral, caryophyllene, geranyl acetate, caryophyllene oxide, citronellal, and linalool. Fourier transform infrared (FTIR) results revealed the interaction between components of the essential oil and polymer matrix. Scanning electron microscopy (SEM) revealed that films loaded with the highest concentration (0.2%) of MOEO showed more homogeneous structure with fewer particles, cracks, and pores as compared to control film sample. MOEO-incorporated films exhibited higher elongation at break (EAB) (30.24–36.29%) and thickness (0.068–0.073 mm); however, they displayed lower tensile strength (TS) (3.48–1.25 MPa) and transparency (87.30–82.80%). MOEO-loaded films demonstrated superior barrier properties against water vapors. According to the results, the incorporation of MOEO into pectin–collagen composite hydrogel-based films resulted in higher antioxidant properties, indicating that MOEO has the potential to be used in active food packaging material for potential applications. Full article