Search Results (2,602)

Background: Plants of the genus Nepeta are widely used in ethnomedicine for treating inflammatory disorders due to their rich content of bioactive compounds. This study investigated how extraction temperature specifically affects the bioactive potential of aqueous extracts from wild-grown Nepeta nuda L. Methods: The previously used maceration approach for this plant was applied at 30–60 °C to flowers, leaves, and stems. Phytochemical profiling included spectrophotometric assays, metabolite identification, and quantification. Biological activities reported for this plant were assessed, including antioxidant, anti-inflammatory, antiviral, antiproliferative, and antibacterial capacities. Results: Extraction yield was highest in flowers and leaves, where it increased significantly with rising temperature, while stems were less productive. All plant organs exhibited notable bioactivity falling into two groups: lower temperatures (30 and 40 °C) were optimal for antiviral and anti-inflammatory effects, whereas and higher temperatures (50 and 60 °C) enhanced antioxidant potential. The phytochemical composition, evaluated at representative extraction temperatures, revealed differential accumulation of p-coumaric acid and luteolin in all organs at 40 °C, while extraction at 60 °C corresponded to elevated levels of phenolic compounds. Flower extracts were confirmed to have the richest metabolic composition and were therefore subjected to further investigation. Extracts obtained at 40 °C influenced C1q binding, supporting their anti-inflammatory activity, whereas extraction at 60 °C resulted in stronger antiproliferative activity in colon cancer cell line. Antibacterial effects were similar at both temperatures. Conclusions: These findings highlight the importance of optimizing extraction conditions for future pharmacological applications of N. nuda. Full article

Fucoidan is a sulfated polysaccharide derived from brown seaweed, reported to possess diverse biological activities that make it a molecule of great interest for nutraceutical and biomedical applications. A significant challenge to its wider implementation is a lack of understanding of the relationship between fucoidan’s structural and chemical characteristics with its biological activity. So far, approaches to identifying these relationships have been limited to qualitative comparisons of chemical and biological datasets or through chemically modified fucoidans. This work aimed to apply a formal methodology to elucidate potential relationships worthy of further exploration. The biological activity of commercial fucoidan extracts was assessed after detailed chemical characterization. The extracts exhibited multiple bioactivities, notably antioxidant activity, antiviral activity against Nipah virus, antifungal activity against Candida dubliensis and prebiotic effects on Lactobacillus casei, with no antifungal activity against Candida albicans, Candida auris and Cryptococcus neoformans, nor antibacterial effects against Klebsiella pneumoniae. Correlation analysis of biological activity and extract chemical characterization data identified several potential key quality attributes. Other than high fucose content, high sulfate content is identified as potentially important for antioxidant, antiviral, antifungal, and prebiotic activities. This work addressed the literature’s debate regarding the optimal molecular weight for bioactivity, suggesting that it depends on the specific microbe to which a fucoidan extract is applied. This study demonstrated that a formalized comparative approach, linking chemical and structural data with biological activity, can effectively identify important characteristics of fucoidan for a specific bioactivity. Future work will focus on expanding this approach by assessing the bioactivity of a wider array of chemically characterized fucoidan extracts. Additionally, extracts possessing identified quality attributes should be produced and employed in mechanistic bioactive studies to further validate the correlations drawn in this work. Full article

Due to its abundant content of biologically active compounds, Althaea officinalis L. (marshmallow) has been extensively researched and applied in both the food and pharmaceutical industries. This study aimed to evaluate hydroethanolic and natural deep eutectic solvent (NADES) extracts from leaves, flowers, and roots in terms of their chemical composition and biological activities. Extracts were characterized using chromatographic and spectrophotometric methods. Phytochemical profiling by HPLC-MS revealed a diverse composition, with 35 secondary metabolites identified or tentatively assigned, mainly hydroxycinnamic acid derivatives and flavonoid glycosides. GC-MS analysis of the ethanol extracts identified ten free amino acids, seven organic acids, several mono- and disaccharides, and one oligosaccharide. Their concentrations varied across different parts of the plant depending on the specific metabolism of the respective organ. Ethanolic extracts showed the highest total phenolic content (up to 176 mg GAE/L), while flower extracts exhibited the strongest antioxidant activity (DPPH up to 89 µmol TE/L). The antimicrobial potential of the extracts was assessed by the agar well diffusion method. NADES1 extracts demonstrated significant antibacterial activity, with inhibition zones reaching up to ~34 mm, whereas NADES2 extracts were largely inactive. In contrast, antifungal activity was negligible or absent across all samples. Full article

Background/Objectives: Early-stage antibacterial discovery requires balancing activity with broader developability-related properties. This study developed a Fivefold Maximum Drug-Likeness strategy (5F-MDL) as a multidimensional, developability-aware framework for prioritizing antibacterial candidates against Escherichia coli (E. coli). Methods: An ensemble of endpoint-specific deep learning models was used to construct a 33-dimensional predicted property spectrum. Approximately 16 million commercially available molecules were screened by comparing their normalized property profiles with those of clinically approved cephalosporin reference drugs. Fifteen top-ranked candidates were selected for experimental evaluation. Antibacterial activity was assessed by disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Molecular docking, molecular dynamics simulations, MM-PBSA analysis, and a Bocillin-FL competition labeling assay were used as target-related supportive analyses. Results: Among the 15 prioritized candidates, three compounds showed measurable antibacterial activity against E. coli ATCC 25922. M2 showed the most favorable in vitro profile among the active candidates, with an MIC of 25.6 µg/mL and an MBC of 51.2 µg/mL, although its potency remained weaker than that of cefuroxime. Docking, molecular dynamics, and MM-PBSA analyses suggested that M2 could maintain a relatively stable noncovalent interaction pattern within the modeled PBP2 pocket, and the Bocillin-FL assay showed that M2 reduced fluorescent probe labeling of PBP2 in vitro. Conclusions: These findings provide preliminary proof-of-concept support for 5F-MDL as a multidimensional prioritization strategy for early-stage antibacterial candidate selection. M2 should be regarded as a preliminary antibacterial hit for further optimization rather than as a validated lead compound. Broader applicability, comparative advantage, and mechanistic relevance require further validation using larger candidate sets, resistant clinical isolates, systematic benchmarking, and direct target-validation experiments. Full article

This study reports on the physico-chemical and in vitro biological characterization of chromium-doped hydroxyapatite (10CrHAp, Cr³⁺, Ca_10-xCr_x(PO₄)₆(OH)₂, x_Cr = 0.1) and chromium-doped hydroxyapatite in dextran matrix (10CrHAp-Dx) coatings, prepared for the first time via the spin coating technique. X-ray diffraction analysis and Rietveld refinement were used to characterize the materials. Fourier-transform infrared (FTIR) spectroscopy confirmed the presence of functional groups specific to hydroxyapatite. Scanning electron microscopy (SEM) observations revealed the presence of a conglomerate of nanoparticles distributed unevenly across the coatings surface. Atomic force microscopy (AFM) showed that both coatings presented continuous surfaces with uniform morphology. The in vitro biocompatibility of 10CrHAp and 10CrHAp-Dx coatings was evaluated using human osteoblast-like MG63 cell line and MTT assay. SEM and MM visualization assessed the cell adhesion and proliferation and morphological changes in the adhered cells. The antibacterial properties of the 10CrHAp and 10CrHAp-Dx coatings was assessed in vitro against two of the most common bacterial reference strains, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923. Overall, the coatings achieved log reductions up to ~9.35, corresponding to a bacterial kill rate (for S. aureus) exceeding 99.99%, with 10CrHAp-Dx showing slightly superior performance. Similar behavior (log reductions of ~8.6 and ~8.9, respectively, indicating a sustained antibacterial effect and >99.99% bacterial elimination) was observed and for Pseudomonas aeruginosa. AFM was used to evaluate the bacterial cells interaction with the coating’s surfaces. The biological assays demonstrated that both coatings possess notable antibacterial activity, underscoring their potential in biomedical applications, particularly in the design of new antimicrobial devices. Full article

Lactic acid bacteria are important components of the early gut microbiota in piglets and may contribute to gastrointestinal stability and control of enteric pathogens, particularly under increasing restrictions on antibiotic use in livestock production. This study aimed to perform in vitro phenotypic screening and characterization of lactic acid bacteria isolated from feces of suckling piglets aged 7–28 days. A total of 42 fecal samples were collected and cultured on selective media, yielding 318 colonies, of which 135 Gram-positive, rod-shaped, catalase-negative isolates were selected for further evaluation. These isolates were assessed for tolerance to acidic conditions (pH 2.0–3.1), bile salts (0.3–0.5%), cell surface hydrophobicity, hemolytic activity, and antibacterial activity against Escherichia coli and Staphylococcus aureus. Among the tested isolates, only two (PMvet212 and PMvet318) demonstrated limited tolerance to acidic and bile conditions and exhibited moderate antibacterial activity, with inhibition zones of approximately 10–12 mm. Identification using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry indicated that PMvet212 was closely related to Lactobacillus brevis, whereas PMvet318 was identified at the genus level as Lactobacillus sp. However, both isolates exhibited α-hemolytic activity and therefore did not meet the safety criteria required for probiotic application. In conclusion, although piglet-derived lactic acid bacteria may exhibit certain functional properties, the present findings highlight that probiotic potential is strain-specific and that rigorous multi-step screening, together with further in vivo validation, is essential before practical application can be considered. Full article

Cystic fibrosis (CF)-associated lung infections caused by Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) remain difficult to treat due to multidrug resistance and the redox instability of the pulmonary environment, which can impair antibiotic efficacy. In this study, we investigated alvinellacin (ALV), a disulfide-stabilized β-hairpin antimicrobial peptide (AMP) derived from the deep-sea polychaete Alvinella pompejana (A. pompejana), as a potential therapeutic agent naturally adapted to redox-fluctuating conditions. The antibacterial and antibiofilm activities of ALV were evaluated against multidrug-resistant (MDR) clinical isolates under CF-like reducing conditions (6 mM dithiothreitol (DTT)). Circular dichroism (CD) analysis showed that DTT did not alter the β-hairpin secondary structure of ALV, supporting its structural stability in CF-like environments. Mechanistic analyses included pore-forming assay, membrane interaction studies, scanning electron microscopy (SEM), lipid-binding assays, cytotoxicity testing, and resistance induction assays, while in vivo efficacy was assessed using the Galleria mellonella infection model. ALV demonstrated strong bactericidal activity that was maintained in the presence of NaCl or human serum. ALV did not induce bacterial resistance and effectively inhibited early-stage biofilm formation and disrupted preformed biofilms, including those of the clinical isolate, even under reducing conditions. The peptide showed selective permeabilization of bacterial membranes linked to its stronger affinity for bacterial membrane lipids and negligible interaction with host-like membranes, with no observed cytotoxicity. In vivo, ALV significantly improved survival in infected larvae. These findings highlight ALV as a promising redox-resilient antimicrobial candidate for treating MDR CF lung infections. Full article

This study evaluates fungal-assisted extraction by solid-state fermentation (FAE-SSF) as a green alternative for recovering phenolic compounds from Moringa oleifera leaves and compares it with conventional maceration, focusing on their effects on antimicrobial and antioxidant properties. FAE-SSF was carried out using Aspergillus niger, and phenolic compounds were quantified as total polyphenols (hydrolysable and condensed tannins), followed by purification and characterization by HPLC-ESI-MS. Biological activities were assessed through antibacterial, antifungal, and DPPH assays. FAE-SSF increased total phenolic content to 20.3 ± 1.7 mg TP/g dry basis at 96 h, representing a 1.53-fold increase compared to maceration (13.3 ± 0.3 mg TP/g db at 24 h). However, maceration showed higher productivity due to shorter extraction time. FAE-SSF extracts exhibited improved antibacterial activity against Staphylococcus aureus, while no activity was observed against Shigella sp., and antifungal activity was lower compared to maceration. Antioxidant activity was also reduced in FAE-SSF extracts (39 ± 7%) compared to maceration (71 ± 4%). HPLC-ESI-MS analysis revealed that maceration preserved a greater diversity of phenolic compounds, whereas FAE-SSF induced biotransformation and reduction of key flavonoids. These results indicate that FAE-SSF enhances phenolic recovery but alters chemical composition and bioactivity, highlighting the importance of process optimization depending on the desired functional properties. Full article

This study aimed to investigate the wound-healing mechanisms of chitosan with a defined molecular weight (MW) and degree of deacetylation (DD), and to explore its potential in hydrogel formulations, optimized for enhanced antibacterial performance. An active molecular chitosan (AMC) was prepared via enzymatic treatment to target a specific MW range with excellent biological activity. The antibacterial, anti-inflammatory, and wound-healing effects of AMC-based hydrogels were evaluated. Given AMC’s antibacterial activity against vancomycin-resistant Staphylococcus aureus (VRSA), its anti-inflammatory effects were also evaluated in full-thickness wounds in BALB/c nude mice. Anti-inflammatory effects were assessed using ELISA and immunohistochemical staining to measure levels of IL-1β, IL-4, IL-6, IL-10, and TNF-α. AMC treatment significantly reduced wound size and suppressed inflammatory cytokine production. These results suggest that hydrogels containing AMC may enhance both antibacterial and anti-inflammatory properties, potentially promoting wound healing. Full article

Objectives: Seawater-immersed burn wounds are highly susceptible to contamination, persistent inflammation, oxidative stress, and delayed healing, while current irrigation solutions remain suboptimal for such acute injuries. This study aimed to evaluate the therapeutic efficacy and underlying mechanisms of plasma-activated water (PAW) as a novel irrigation strategy for these complex wounds. Methods: The antibacterial efficacy of PAW against marine pathogens was first evaluated in vitro. Subsequently, a rat model of seawater-immersed burn injury was established in male Sprague-Dawley (SD) rats to assess the therapeutic effects of PAW irrigation on wound healing, infection control, and underlying biological mechanisms. Results: In vitro, PAW significantly eradicated two major marine pathogens, Vibrio vulnificus and Vibrio parahaemolyticus (p < 0.001). In vivo, PAW markedly accelerated wound closure, achieving complete healing in 23.60 ± 6.50 days vs. 38.67 ± 2.08 days (Normal saline group) and 58.33 ± 10.97 days (Model group) (p < 0.05). PAW significantly reduced bacterial burden, modulated inflammation by decreasing interleukin-6 and increasing interleukin-10, and alleviated oxidative stress, as evidenced by reduced malondialdehyde levels and enhanced superoxide dismutase activity. Histological evaluation demonstrated enhanced re-epithelialization, collagen deposition, and increased expression of vascular endothelial growth factor and platelet endothelial cell adhesion molecule-1. No adverse effects on serum biochemistry or major organ histopathology were observed. Conclusions: PAW may be a safe, promising, and multifunctional irrigation strategy that promotes seawater-immersed burn healing through coordinated antibacterial, anti-inflammatory, antioxidant, and pro-angiogenic effects, highlighting its strong potential for clinical translation. Full article

Snail mucus is increasingly investigated as a biologically compatible source of multifunctional biomolecules for pharmaceutical and dermatological use. However, the chemical profile and biological activities of mucus from the Moroccan endemic terrestrial snail Otala tingitana remain poorly characterized. In addition, the influence of heliciculture diet on the composition and functional properties of the mucus remains unclear. Here, O. tingitana was reared for 140 days under controlled conditions and fed a basal flour diet or the same diet supplemented with 3% Rosmarinus officinalis, Origanum compactum, or Thymus zygis subsp. zygis. Mucus from wild snails was included for comparison. Mucus samples were chemically profiled by GC–MS and evaluated for antibacterial activity, antioxidant capacity, wound-healing efficacy in mice, and histological anti-inflammatory effects, and evaluated semi-quantitatively based on the degree of inflammatory cell infiltration. GC–MS identified 13 compounds and demonstrated clear diet-dependent shifts in dominant components. All mucus samples exhibited broad-spectrum antibacterial activity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium (inhibition zones 10.31–14.30 mm; MIC 120–240 µg/mL), with predominantly bactericidal profiles (MBC/MIC < 4) and significantly enhanced activity in plant-supplemented groups (p < 0.05). Antioxidant performance improved markedly with medicinal-plant supplementation, reaching low IC₅₀ values (best ≈ 1.18 mg/mL) compared with basal-diet mucus. In vivo, topical application accelerated wound closure, achieving complete healing in <21 days, versus 28 days in untreated controls. In addition, histological assessment showed faster resolution of inflammatory cell infiltration in treated groups. Collectively, these findings provide the first integrated evidence that O. tingitana mucus possesses antibacterial, antioxidant, wound-healing, and anti-inflammatory activities, and that heliciculture diet is a practical lever to optimize its bioactive profile. Further studies should prioritize standardized manufacturing, contaminant control, and safety/toxicology assessment before translational development. Full article

This work presents an energy-efficient and simple method for producing luminescent, antibacterial sulfur quantum dots (SQDs). For the first time, polyethyleneimine (PEI)-coated SQDs were synthesized via a mechanochemical technique, utilizing either elemental sulfur or sodium thiosulfate as the sulfur source. The roles of hydrogen peroxide (H₂O₂) as an etching agent and of sodium hydroxide (NaOH) in the PEI-mediated SQD formation were investigated. The as-synthesized SQDs were characterized by UV-visible, Raman, infrared (IR), and photoluminescence (PL) spectroscopy, as well as by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Both TEM and AFM analyses revealed similarly small SQD sizes (average diameter ~3 nm), independent of the sulfur source used. The influence of synthesis conditions on the optical properties, including the photoluminescence quantum yield (QY), was evaluated. SQDs derived from elemental sulfur, PEI, and NaOH exhibited the best water solubility and the strongest photoemission in the 400–550 nm range. Antibacterial activity was assessed against representative Gram-positive and Gram-negative strains, and minimum inhibitory concentration (MIC) values were determined. The PEI-coated SQDs demonstrated antibacterial activity against the Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus, and Staphylococcus epidermidis, which is attributed primarily to the sulfur component. Full article

A bacterial strain M4 exhibiting high nattokinase (NK) activity and favorable antibacterial properties was isolated from fermented soybean paste in Northeast China. Based on morphological observation, physiological and biochemical characterization, 16S rDNA sequence analysis, and whole-genome sequencing, the strain was identified as Bacillus velezensis. Its probiotic potential and safety were systematically evaluated using a combination of in vitro assays and genome mining. Genomic analysis revealed that M4 possessed a complete genome consisting of a single circular chromosome of 4,473,838 bp with a GC content of 46.94%, encoding 4516 predicted proteins. Functional domain annotation identified four proteins (XLQ58132.1, XLQ58158.1, XLQ59409.1, and XLQ59873.1) containing both the Peptidase inhibitor I9 and Peptidase S8 domains, confirming the presence of the typical molecular signature of NK. Furthermore, the genome harbored 132 genes encoding carbohydrate-active enzymes, 37 biosynthetic gene clusters, and 142 genes encoding proteolytic enzymes. Comparative genomic analysis revealed a close phylogenetic relationship with other B. velezensis strains and identified 98 strain-specific genes. Safety assessment demonstrated that M4 exhibited no hemolytic activity, was susceptible to eight commonly tested antibiotics, and lacked genes encoding high-risk virulence factors. Probiotic characterization indicated that M4 exhibited certain levels of gastrointestinal tolerance, acid resistance, bile salt resistance, antioxidant activity, and antibacterial properties. In conclusion, B. velezensis M4 shows potential for development as a functional strain. Full article

Conventional and emerging extraction methods for recovering phenolic compounds (PCs) from Pinus radiata bark were investigated for their potential use in bio-composites and bio-based biomaterial applications. To optimize the recovery process, a Response Surface Methodology (RSM) based on a Box–Behnken design was used to evaluate the effects of extraction time (20–100 min), temperature (20–80 °C), and water or ethanol-water solvent concentrations with β-cyclodextrin (βCD) or NaOH (0.5–1.5% w/v CD/db). Polyphenolic profiles of the extracts were characterized using Fourier transform infrared spectroscopy (FTIR), LC-LTQ-Orbitrap-MS, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to evaluate the thermal stability and degradation behavior of the powdered extracts. Antioxidant capacity (DPPH, FRAP, ABTS) and antibacterial activity against Escherichia coli and Staphylococcus aureus were assessed by spectrophotometric assays and the agar diffusion method, respectively. Highest extraction yields were obtained using alkaline extraction (14.32%) and ultrasound-assisted extraction (UAE) (13.86%), followed by ethanol extraction (12.74%). Minimum inhibitory concentration (MIC) for P-βCD was 0.04 mg/mL, and the minimum bactericidal concentration (MBC) was 0.32 mg/mL against S. aureus. These results suggest a strong inhibitory capacity at low concentrations and the potential incorporation of these extracts into bio-based antimicrobial biomaterials. Full article

Background/Objectives: The escalating crisis of antibiotic resistance and the inherent limitations of conventional antibiotics necessitate the development of innovative therapeutic strategies. Targeted drug delivery (TDD) offers a powerful approach to enhance efficacy, minimize systemic toxicity, and circumvent bacterial resistance. This systematic review aims to evaluate the potential of unique bacterial transport systems (BTSs), surface specific receptors and intracellular enzymes as platforms for TDD via the “Trojan Horse” strategy (THS). Methods: A comprehensive literature review was conducted, focusing on studies that investigated the specificity and mechanisms of BTSs responsible for the uptake of metabolites that are essential for and unique to bacteria. This includes an analysis of transport systems for siderophores, bacteria-specific sugars, cell wall components, D-amino acids, and vitamins. We assessed preclinical and clinical examples of drug conjugates utilizing these pathways, as well as emerging platforms such as bacteriophage-derived proteins, antibody–antibiotic conjugates, and bacterial extracellular vesicles (EVs). Results: BTSs demonstrate high specificity for their cognate substrates, providing effective molecular gateways for TDD of drugs photosensitizers and diagnostic probes in form of conjugates. The siderophore–cephalosporin conjugate cefiderocol represents a clinically validated example, having received FDA approval. Preclinical studies further reveal that conjugates utilizing sugars (e.g., maltose, trehalose) and vitamins (e.g., B12) can significantly enhance antibiotic uptake and activity against both Gram-positive and Gram-negative pathogens, including drug-resistant strains. Emerging platforms like bacteriophage endolysins and engineered EVs show promise for overcoming biological barriers such as bacterial outer membranes and intracellular host niches. Conclusions: The THS leveraging BTSs represents a clinically viable and promising avenue for next-generation antibacterial therapies. Advantages of BTS include overcoming bacterial resistance, such as reduced membrane permeability and efflux pumps, enabling the “revival” of antibiotics that are poorly permeable or toxic, increasing their local concentration at the target site and reducing side effects on host cells. While significant progress has been made, a striking disconnect persists between the hundreds of conjugates demonstrating potent in vitro activity and the limited agent that has achieved clinical use. This in vitro–in vivo gap reflects, in large part, the early stage of this field rather than a fundamental failure. Further research is critically needed not only to identify novel BTSs and optimize drug-linker chemistry, but also to systematically address the translational barriers—including poor pharmacokinetics, immunogenicity, and unexpected toxicity—that have prevented most promising candidates from advancing beyond preclinical evaluation. Full article