Characterization and Biomedical Applications of Green-Synthesized Selenium Nanoparticles Using Tridax procumbens Stem Extract.

Background Selenium nanoparticles (SeNPs) are one of the metal nanoparticles that have been widely utilized for their anti-microbial, anti-oxidant, anti-inflammatory activities, and other biomedical applications. Tridax procumbens (TP) stem extract is a promising herb species rich in flavonoids, tannins, alkaloids, phytosterols, and hydroxycinnamates, which play a major role in wound healing applications.  Aim The study aims to synthesize SeNPs using TP stem extract, characterizations, and its biomedical applications. Materials and methods SeNPs were synthesized using TP stem extract. The green synthesis of SeNPs was confirmed by ultraviolet-visible (UV-vis) spectra analysis. The synthesized SeNPs were characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The agar well diffusion method was utilized to evaluate the anti-bacterial properties of the green synthesized SeNPs using TP stem extract. The anti-oxidant effect of SeNPs was tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ferric-reducing anti-oxidant power assay (FRAP), and hydroxyl radical scavenging assay (H2O2). The anti-inflammatory effect was investigated using the bovine serum albumin assay and egg albumin denaturation method, and the cytotoxic effect of the green synthesized SeNPs was tested using the brine shrimp lethality (BSL) assay. Results The green synthesis of SeNPs was confirmed using different types of analysis techniques. The characterizations were done by UV-visible spectroscopy analysis, exhibiting a maximum peak at the range of 330 nm. SEM analysis revealed the shape of the nanoparticle to be hexagonal. The agar well diffusion method exhibited the anti-bacterial efficacy of SeNPs against wound microorganisms with a zone of inhibition of 14.6 mm for Escherichia coli (E. coli), 15.8 mm for Staphylococcus aureus (S. aureus), and 15.4 mm for Pseudomonas aeruginosa (P. aeruginosa). The TP stem-mediated SeNPs showed potential effects in anti-oxidant, anti-inflammatory, and cytotoxic activity, which shows very little toxicity. Conclusion Overall, the green synthesis of TP-stem-mediated SeNPs has great potential in biomedical applications. Thus, the synthesized SeNPs exhibit significant anti-bacterial efficacy against wound pathogens. The TP stem-mediated SeNPs showed potential effects in anti-oxidant, anti-inflammatory, and cytotoxic activity, which shows low toxicity. Furthermore, the green-synthesized SeNPs can be utilized in therapeutic management.

Relationship between oligoarginine-induced membrane damage of single Escherichia coli cells and entry of the peptide into the cytoplasm.

Cell-penetrating peptides (CPPs) can enter the cytosol of eukaryotic cells without killing them whereas some CPPs exhibit antimicrobial activity against bacterial cells. Here, to elucidate the mode of interaction of the CPP nona-arginine (R9) with bacterial cells, we investigated the interactions of lissamine rhodamine B red-labeled peptide (Rh-R9) with single Escherichia coli cells encapsulating calcein using confocal laser scanning microscopy. After Rh-R9 induced the leakage of a large amount of calcein, the fluorescence intensity of the cytosol due to Rh-R9 greatly increased, indicating that Rh-R9 induces cell membrane damage, thus allowing entry of a significant amount of Rh-R9 into the cytosol. To determine if the lipid bilayer region of the membrane is the main target of Rh-R9, we then investigated the interaction of Rh-R9 with single giant unilamellar vesicles (GUVs) comprising an E. coli polar lipid extract containing small GUVs and AlexaFluor 647 hydrazide (AF647) in the lumen. Rh-R9 entered the GUV lumen without inducing AF647 leakage, but leakage eventually did occur, indicating that GUV membrane damage was induced after the entry of Rh-R9 into the GUV lumen. The Rh-R9 peptide concentration dependence of the fraction of entry of Rh-R9 after a specific interaction time was similar to that of the fraction of leaking GUVs. These results indicate that Rh-R9 can damage the lipid bilayer region of a cell membrane, which may be related to its antimicrobial activity.

Formulation of Neem and Echinacea Gel for Oral Health Along With the Evaluation of Antimicrobial, Cytotoxic, Anti-inflammatory, and Free Radical Scavenging Activity: An In Vitro Study.

Background Herbs have been used in medical practice for centuries and continue to play a significant role in modern complementary and alternative medicine. Phytochemicals in these herbs possess strong antioxidant and anti-inflammatory properties, which are beneficial in targeting oral health issues, such as dental plaque, gingivitis, and oral microbial infections. As research progresses, the challenge remains to translate these natural compounds into safe, effective, and accessible treatments for a wide range of diseases. Aim The aim of this research was to formulate the neem and echinacea gel along with the evaluation of antimicrobial, anti-inflammatory, free-radical scavenging activity, and cytotoxic potential. Materials and methods The neem and echinacea gel was prepared using a concentrated powdered mixture of neem and echinacea (5 grams each) to which 100 ml of distilled water was added, and the mixture was boiled for 30 minutes at 60°C. The 10 ml concentrate was mixed with 20 ml of a carbopol and carboxymethyl cellulose (CMC) mixture and mixed thoroughly, which resulted in neem and echinacea gel. Then, the antimicrobial, anti-inflammatory, cytotoxic potential, and free-radical scavenging activity of the gel were evaluated. The data obtained were statistically analyzed with the help of a paired t-test, where a p-value of less than 0.05 was considered statistically significant. Results The antimicrobial assay showed that neem and echinacea gel at the concentration of 100 micrograms showed a greater zone of inhibition against Staphylococcus aureus (3.15 ± 0.26), Streptococcus mutans (2.48 ± 0.45), Enterococcus faecalis (2.89 ± 0.15), and Candida albicans (4.28 ± 0.87). The cytotoxic test revealed that even at an 80 µg concentration of the extract, more than 70% of the nauplii were vital, which indicated that the gel was not cytotoxic. The highest anti-inflammatory activity (78.39 ± 1.82) of the gel was seen at 50 micrograms when compared with diclofenac sodium (73.16 ± 1.80). The free radical scavenging activity showed that the 2,2-diphenyl-1-picrylhydrazyl (DPPH) absorbance of the neem and echinacea extract was highest at 50 micrograms.  Conclusion The combination of neem and echinacea extract-based gel possessed high antimicrobial and anti-inflammatory activity when compared with standard drugs, such as amoxicillin and diclofenac sodium. The antioxidant activity of the gel was equal to butylated hydroxytoluene (BHT), and also the gel has a low cytotoxic potential even at its higher concentrations. Hence, the gel can be used as a natural remedy with minimal side effects, making it a valuable alternative to chemical agents.

Phytochemical and biological investigation of Astragalus Caprinus L.

BACKGROUND: cultivated and wild plants are used to treat different ailments. The Astragalus genus is found in temperate and dry climates; thus, it is found in Egypt and the arab world. Astragalus caprinus has a good amount of bioactive chemicals, which may help explain its therapeutic effects in reducing the risk of consequences from disease. METHOD: The phytochemical investigation of the herb and roots of Astragalus caprinus L. included the analytical characterization for the petroleum ether components by GC/MS, unsaponifiable matter (unsap. fraction), and fatty acids (FAME) investigation by GLC analysis. Main flavonoids were chromatographically isolated from ethyl acetate and n-butanol extracts. In vitro antimicrobial activity has been tested against the Gram-positive bacteria Staphylococcus aureus and Streptococcus mutans for different plant extracts, the Gram-negative bacteria Pseudomonas aeruginosa and Klebsiella pneumonia, the fungus Candida albicans and Aspergillus niger, and the Escherichia coli bacterium. Metabolite cytotoxicity was examined using the MTT assay against HepG-2 (human liver carcinoma) and MCF-7 (breast carcinoma). RESULTS: Identifying the important components of the herb and root petroleum ether extracts was achieved. Using column chromatography, luteolin, cosmosiin (apigenin-7-O-glucoside), and cynaroside (luteolin-7-O-glucoside) were separated and identified using UV, NMR, and Mass Spectroscopy. Root extracts displayed potential antimicrobial activity against most of the tested pathogens. Both extracts (herb and roots) were active against the MCF-7 cell line and HepG-2 cell line with IC50 62.5 ± 0.64 and 72.4 ± 2.3 µg/ml, and 75.9 ± 2.5 and 96.8 ± 4.2 µg/ml, respectively. CONCLUSION: Astragalus caprinus seems to be a promising source of bioactive compounds that could potentially aid in preventing disease complications and address common health issues in developing countries. Moreover, the various parts of this plant could be utilized as natural raw materials for producing health-boosting products that could address common health issues in developing countries.

Formulation of Garlic Essential Oil-assisted Silver Nanoparticles and Mechanistic Evaluation of their Antimicrobial Activity against a Spectrum of Pathogenic Microorganisms.

BACKGROUND: The synthesis of nanoparticles using the principle of green chemistry has achieved huge potential in nanomedicine. Here, we report the synthesis of silver nanoparticles (Ag- NPs) employing garlic essential oil (GEO) due to wide applications of GEO in the biomedical and pharmaceutical industry. OBJECTIVE: This study aimed to synthesise garlic essential oil-assisted silver nanoparticles and present their antimicrobial and antibiofilm activities with mechanistic assessment. METHOD: Initially, the formulation of AgNPs was confirmed using different optical techniques, such as XRD, FT-IR, DLS, zeta potential, SEM, and EDX analysis, which confirmed the formulation of well-dispersed, stable, and spherical AgNPs. The antimicrobial and antibiofilm activity of GEO-assisted AgNPs was evaluated against a spectrum of pathogenic microorganisms, such as Gram-positive (S. aureus and B. subtilis) and Gram-negative (E. coli and P. aeruginosa) bacteria. RESULTS: The AgNPs exhibited remarkable antimicrobial and anti-biofilm activity against all tested strains. The mechanism behind the antimicrobial activity of AgNPs was explored by estimating the amount of reactive oxygen species (ROS) generated due to the interaction of AgNP with bacterial cells and observing the morphological changes of bacteria upon AgNP interaction. CONCLUSION: The findings of this study concluded that ROS generation due to the interaction of AgNPs with bacterial cells put stress on bacterial membranes, altering the morphology of bacteria, exhibiting remarkable antimicrobial activity, and preventing biofilm formation.

Studies on In Vitro Antimicrobial, Anticancer, and Anti-oxidative Inflammatory Response of Methanolic Tuber Extracts Derived From Terminalia chebula.

Aim This study aims to investigate the antibacterial, antifungal, and phytochemical properties of methanolic tuber extracts from Terminalia chebula. Additionally, the study seeks to assess the in vitro anticancer effects of these extracts on an oral cancer cell line, as well as their antioxidant and anti-inflammatory activities. Materials and methods The research involves examining the antibacterial and antifungal properties of methanolic tuber extracts from Terminalia chebula. The phytochemical composition will be analyzed using standard techniques. The in vitro anticancer effects will be tested on an oral cancer cell line, while antioxidant and anti-inflammatory activities will be evaluated through appropriate assays. Results The study demonstrated that Terminalia chebula methanolic tuber extracts exhibit cytotoxic effects on the oral cancer cell line (KB-1), reducing cell viability as evidenced by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A concentration of 30 µg/mL induced notable morphological changes observed under an inverted fluorescence microscope. Antioxidant assays showed a maximum absorption of 85.3% with 50 µL of the extract, while anti-inflammatory tests revealed a 76.0% absorption. Antimicrobial activity, assessed via agar-well diffusion, indicated significant antibacterial effects, especially against Streptococcus mutans and Candida albicans at higher concentrations. The findings suggest promising therapeutic potential for Terminalia chebula extracts. Conclusion Terminalia chebula tuber extracts may treat diseases caused by studied organisms. The study suggests that methanolic extracts from Terminalia chebula tubers have potential commercial value due to their anti-inflammatory, antioxidant, and cytotoxic properties. The extracts induced apoptosis in an oral cancer cell line at 30 µg/mL after 24 hours. Further research is needed to understand the active components and underlying molecular mechanisms.

Potential probiotic and functional properties of Brettanomyces strains isolated from kombucha tea.

Kombucha, a beverage traditionally obtained through the fermentation of tea, is believed to have beneficial health properties. Therefore, characterizing the microorganisms responsible for this fermentation is essential to demonstrate its potential health benefits and to identify candidates for new probiotics. In this study, four probiotic yeast strains isolated from kombucha tea were identified, by the PCR-RFLP analysis of the ribosomal ITS region and the sequence of the D1/D2 domain of the 26S rDNA, as Brettanomyces bruxellensis (UVI55 and UVI56) and B. anomalus (UVI57 and UVI58). Properties relevant to probiotics were also studied in these strains. All of them showed excellent survival in simulated gastric (99%-100%) and duodenal (95%-100%) juices. The ability to self-aggregate (38%-100%), adhesion to xylene (15%-50%) and, above all, adhesion to Caco-2 cells (4%-21%), revealed its potential capacity to adhere to the intestinal epithelium. In addition, the tested strains showed excellent antioxidant capacity (82%-94%), antimicrobial activity against different pathogens (Escherichia coli, Staphylococcus aureus, Salmonella enterica, Listeria monocytogenes, and Bacillus cereus), as well as remarkable cytotoxic activity against colon, melanoma and ovarian tumor cell lines. Finally, using Caenorhabditis elegans as a model, strain UVI56 exhibited ability to both extend the lifespan of the nematode and protect it against infection by S. enterica. These results support the probiotic and functional properties of the analyzed strains. In conclusion, the study revealed that kombucha tea could be a source of potential probiotics that contribute to its health-promoting properties and that the characterized Brettanomyces strains could be exploited directly as probiotics or for the development of new functional foods.

Exploring the antimicrobial and antioxidant properties of Lentzea flaviverrucosa strain E25-2 isolated from Moroccan forest soil.

The alarming rise in antimicrobial resistance (AMR) has created a significant public health challenge, necessitating the discovery of new therapeutic agents to combat infectious diseases and oxidative stress-related disorders. The Lentzea flaviverrucosa strain E25-2, isolated from Moroccan forest soil, represents a potential avenue for such research. This study aimed to identify the isolate E25-2, obtained from soil in a cold Moroccan ecosystem, and further investigate its antimicrobial and antioxidant activities. Phylogenetic analysis based on 16S rRNA gene sequences revealed the strain's classification within the Lentzea genus, with a sequence closely resembling that of Lentzea flaviverrucosa AS4.0578 (96.10% similarity). Antimicrobial activity in solid media showed moderate to strong activity against Staphylococcus aureus ATCC 25923, Bacillus cereus strain ATCC 14579, Escherichia coli strain ATCC 25922, Candida albicans strain ATCC 60193 and 4 phytopathogenic fungi. In addition, ethyl acetate extract of this isolate demonstrated potent antimicrobial activity against 7 clinically multi-drug resistant bacteria. Furthermore, it demonstrated antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, as well as a significant increase in ferric reducing antioxidant power. A significant positive correlation was observed between antioxidant activities and total content of phenolic compounds (p < 0.0001), along with flavonoids (p < 0.0001). Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of amines, hydroxyl groups, pyridopyrazinone rings, esters and pyrrolopyrazines. The Lentzea genus could offer promising prospects in the fight against antibiotic resistance and in the prevention against oxidative stress related diseases.

A Novel Gum Paint Formulation Derived From Licorice and Triphala: Characteristics and Clinical Significance for Improved Oral Health.

BACKGROUND: The clinical use of antimicrobial agents for managing aphthous ulcers and periodontal diseases has long been a subject of intensive research by numerous investigators. As concerns over the side effects and antibiotic resistance associated with conventional therapies persist, there has been a concerted effort to explore alternative medicinal approaches. In line with this objective, our study introduces a novel herbal gum paint designed specifically to address the therapeutic needs of individuals suffering from oral ulcers and periodontal diseases. MATERIALS AND METHODS: The herbal formulation utilized in our study was prepared using extracts derived from Licorice (Glycyrrhiza glabra) and Triphala, a combination of three fruits: Emblica officinalis, Terminalia chebula, and Terminalia belerica. These ingredients were selected based on their documented medicinal properties. The preparation process involved extraction and formulation techniques optimized for maximum efficacy. Antimicrobial activity was assessed using the bacterial culture method, where the formulation's ability to inhibit the growth of specific bacterial strains relevant to oral health was tested. Meanwhile, cytotoxicity was evaluated using the Brine Shrimp Assay method. Statistical analysis was conducted using a one-way analysis of variance (ANOVA) and Tukey post hoc test to validate the significance of our findings with statistical significance set at p<0.05. RESULTS: The formulation exhibited significant activity against microbes when compared to the control. The cytotoxic activity was present at a concentration of 60 and 80µL, which indicated safe usage within specified concentration ranges, highlighting its potential for clinical application without adverse effects on biological systems. Statistically significant differences were obtained between the antimicrobial activity of the formulated gum paint and the commercial gum paint against Candida albicans species at 25 µL and 80 µL (p=0.00). CONCLUSION: The study underscores the promising therapeutic potential of the herbal gum paint developed in this research. By harnessing the natural antimicrobial and anti-inflammatory properties of Licorice and Triphala, the formulated gum paint showed efficacy against C. albicans. These findings contribute to the growing body of evidence supporting the integration of herbal remedies into mainstream oral healthcare practices. Future investigations could further elucidate the mechanisms underlying its therapeutic actions and explore its broader clinical applications in diverse patient populations.

Nanoemulsions of essential oils against multi-resistant microorganisms: an integrative review.

Microbial resistance to drugs continues to be a global public health issue that demands substantial investment in research and development of new antimicrobial agents. Essential oils (EO) have demonstrated satisfactory and safe antimicrobial action, being used in pharmaceutical, cosmetic, and food formulations. In order to improve solubility, availability, and biological action, EO have been converted into nanoemulsions (NE). This review identified scientific evidence corroborating the antimicrobial action of nanoemulsions of essential oils (NEEO) against antibiotic-resistant pathogens. Using integrative review methodology, eleven scientific articles evaluating the antibacterial or antifungal assessment of NEEO were selected. The synthesis of evidence indicates that NEEO are effective in combating multidrug-resistant microorganisms and in the formation of their biofilms. Factors such as NE droplet size, chemical composition of essential oils, and the association of NE with antibiotics are discussed. Furthermore, NEEO showed satisfactory results in vitro and in vivo evaluations against resistant clinical isolates, making them promising for the development of new antimicrobial and antivirulence drugs.

Synthesis, fungal biotransformation, and evaluation of the antimicrobial potential of chalcones with a chlorine atom.

Chalcones are intermediate products in the biosynthesis of flavonoids, which possess a wide range of biological properties, including antimicrobial and anticancer activities. The introduction of a chlorine atom and the glucosyl moiety into their structure may increase their bioavailability, bioactivity, and pharmacological use. The combined chemical and biotechnological methods can be applied to obtain such compounds. Therefore, 2-chloro-2'-hydroxychalcone and 3-chloro-2'-hydroxychalcone were synthesized and biotransformed in cultures of two strains of filamentous fungi, i.e. Isaria fumosorosea KCH J2 and Beauveria bassiana KCH J1.5 to obtain their novel glycosylated derivatives. Pharmacokinetics, drug-likeness, and biological activity of them were predicted using cheminformatics tools. 2-Chloro-2'-hydroxychalcone, 3-chloro-2'-hydroxychalcone, their main glycosylation products, and 2'-hydrochychalcone were screened for antimicrobial activity against several microbial strains. The growth of Escherichia coli 10,536 was completely inhibited by chalcones with a chlorine atom and 3-chlorodihydrochalcone 2'-O-ß-D-(4″-O-methyl)-glucopyranoside. The strain Pseudomonas aeruginosa DSM 939 was the most resistant to the action of the tested compounds. However, chalcone aglycones and glycosides with a chlorine atom almost completely inhibited the growth of bacteria Staphylococcus aureus DSM 799 and yeast Candida albicans DSM 1386. The tested compounds had different effects on lactic acid bacteria depending on the tested species. In general, chlorinated chalcones were more effective in the inhibition of the tested microbial strains than their unchlorinated counterparts and aglycones were a little more effective than their glycosides.

Mapping a sustainable approach: biosynthesis of lactobacilli-silver nanocomposites using whey-based medium for antimicrobial and bioactivity applications.

This study explores a sustainable approach for synthesizing silver nanocomposites (AgNCs) with enhanced antimicrobial and bioactivity using safe Lactobacillus strains and a whey-based medium (WBM). WBM effectively supported the growth of Lactobacillus delbrueckii and Lactobacillus acidophilus, triggering a stress response that led to AgNCs formation. The synthesized AgNCs were characterized using advanced spectroscopic and imaging techniques such as UV‒visible, Fourier transform infrared (FT-IR) spectroscopy, transmission electron (TEM), and scanning electron microscopy with energy dispersive X-ray analysis (SEM-Edx). Lb acidophilus-synthesized AgNCs in WBM (had DLS size average 817.2-974.3 ± PDI = 0.441 nm with an average of metal core size 13.32 ± 3.55 nm) exhibited significant antimicrobial activity against a broad spectrum of pathogens, including bacteria such as Escherichia coli (16.47 ± 2.19 nm), Bacillus cereus (15.31 ± 0.43 nm), Clostridium perfringens (25.95 ± 0.03 mm), Enterococcus faecalis (32.34 ± 0.07 mm), Listeria monocytogenes (23.33 ± 0.05 mm), methicillin-resistant Staphylococcus aureus (MRSA) (13.20 ± 1.76 mm), and filamentous fungi such as Aspergillus brasiliensis (33.46 ± 0.01 mm). In addition, Lb acidophilus-synthesized AgNCs in WBM exhibit remarkable free radical scavenging abilities, suggesting their potential as bioavailable antioxidants. These findings highlight the dual functionality of these biogenic AgNCs, making them promising candidates for applications in both medicine and nutrition.

In vitro and in silico evaluation of bioactivities and chemical composition of the aerial parts of Anchusa officinalis L. methanol extract.

The main objective of the study is to evaluate the antioxidant, anticancer, and antimicrobial activities of Anchusa officinalis L. in vitro and in silico. The dried aerial parts of A. officinalis L. were extracted with methanol. Total phenolic and flavonoid content was analyzed. Antioxidant and antimicrobial effects were tested against both gram-positive and gram-negative bacteria. Gas chromatography-mass spectrometry analysis revealed the presence of 10 phytochemical compounds, and cyclobutane (26.07%) was identified as the major photochemical compound. The methanol extract exhibited the maximum amount of total phenolic content (118.24 ± 4.42 mg QE/g dry weight of the dry extract) (R2 = 0.994) and the total flavonoid content was 94 ± 2.34 mg QE/g dry weight of the dry extract (R2 = 0.999). The IC50 value for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid was 107.12 ± 3.42 µg/mL, and it was high for 1,1-diphenyl-2-picryl hydrazyl (123.94 ± 2.31 µg/mL). The IC50 value was 72.49 ± 3.14 against HepG2 cell lines, and a decreased value was obtained (102.54 ± 4.17 g/mL) against MCF-7 cell lines. The methanol extract increased the expression of caspase mRNA and Bax mRNA levels when compared to the control experiment (p < .05). The conclusions, A. officinalis L. aerial parts extract exhibited antibacterial, antifungal, and antioxidant activities.

Colletotrichum fructicola co-opts cytotoxic ribonucleases that antagonize host competitive microorganisms to promote infection.

Phytopathogens secrete numerous molecules into the environment to establish a microbial niche and facilitate host infection. The phytopathogenic fungus Colletotrichum fructicola, which causes pear anthracnose, can colonize different plant tissues like leaves and fruits, which are occupied by a diversity of microbes. We speculate that this fungus produces antimicrobial effectors to outcompete host-associated competitive microorganisms. Herein, we identified two secreted ribonucleases, CfRibo1 and CfRibo2, from the C. fructicola secretome. The two ribonucleases both possess ribonuclease activity and showed cytotoxicity in Nicotianan benthamiana without triggering immunity in an enzymatic activity-dependent manner. CfRibo1 and CfRibo2 recombinant proteins exhibited toxicity against Escherichia coli, Saccharomyces cerevisiae, and, importantly, the phyllosphere microorganisms isolated from the pear host. Among these isolated microbial strains, Bacillus altitudinis is a pathogenic bacterium causing pear soft rot. Strikingly, CfRibo1 and CfRibo2 were found to directly antagonize B. altitudinis to facilitate C. fructicola infection. More importantly, CfRibo1 and CfRibo2 functioned as essential virulence factors of C. fructicola in the presence of host-associated microorganisms. Further analysis revealed these two ribonucleases are widely distributed in fungi and are undergoing purifying selection. Our results provide the first evidence of antimicrobial effectors in Colletotrichum fungi and extend the functional diversity of fungal ribonucleases in plant-pest-environment interactions. IMPORTANCE: Colletotrichum fructicola is emerging as a devastating pathogenic fungus causing anthracnose in various crops in agriculture, and understanding how this fungus establishes successful infection is of great significance for anthracnose disease management. Fungi are known to produce secreted effectors as weapons to promote virulence. Considerable progress has been made in elucidating how effectors manipulate plant immunity; however, their importance in modulating environmental microbes is frequently neglected. The present study identified two secreted ribonucleases, CfRibo1 and CfRibo2, as antimicrobial effectors of C. fructicola. These two proteins both possess toxicity to pear phyllosphere microorganisms, and they efficiently antagonize competitive microbes to facilitate the infection of pear hosts. This study represents the first evidence of antimicrobial effectors in Colletotrichum fungi, and we consider that CfRibo1 and CfRibo2 could be targeted for anthracnose disease management in diverse crops in the future.

Enhanced accumulation of biologically active compounds in lichens with potential functional food applications.

Lichens have great potential as food, functional food additives or flavourings. The presence of specific substances with multiple biological activities is one of the characteristics of lichens. However, research on lichens as a food source or functional food additive is limited. The present study simulated, for the first time, the potential bioaccessibility of active compounds from 6 lichen species in simulated gastric and intestinal conditions. An in vitro digestion showed that the lichen substances had different bioaccessibility and stability during digestion. It was found that the application of some metabolic modulators significantly altered the accumulation of metabolites in most species. In addition, the study demonstrated the antimicrobial activity of the tested extracts as well as of 14 isolated lichen metabolites. These multi-directional studies demonstrate the potential of lichens in terms of their use as antimicrobial functional food additives.

Design, synthesis, antimicrobial activity, and mechanism of novel 3-(2,4-dichlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives.

BACKGROUND: Plant pathogens cause substantial crop losses annually, posing a grave threat to global food security. Fungicides have usually been used for their control, but the rapid development of pesticide resistance renders many ineffective, therefore the search for novel and efficient green pesticides to prevent and control plant diseases has become the top priority in crop planting. RESULTS: The results of bioassay studies indicated that most of the target compounds showed certain antimicrobial activity in vitro. In particular, compound X7 showed high inhibitory activity against Xanthomonas oryzae pv. oryzae (Xoo), with an EC50 value of 27.47 µg mL-1, surpassing conventional control agents such as thiazole zinc (41.55 µg mL-1) and thiodiazole copper (53.39 µg mL-1). Further studies on molecular docking showed that X7 had a strong binding affinity with 2FBW. The morphological change observed by scanning electron microscopy indicated that the surface of Xoo appears wrinkled and cracked under X7 treatment and a total of 2662 proteins were identified by label-free proteomic analysis. Three experiments have elucidated the mechanism whereby X7 induced considerable changes in the physiological and biochemical properties of Xoo, which in turn affected the reproduction and growth of bacteria. CONCLUSION: This work represents a pivotal advancement, offering important reference for the research and development therapeutics in combating plant pathogens. © 2024 Society of Chemical Industry.

Coptis rhizome extract influence on Streptococcus pneumoniae through autolysin activation.

This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts' biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance.

New insights into microorganism-derived antibiotics based on identification and antimicrobial activity of antibiotic-producing actinomycetes in kusaya gravy that lead to its high preservability.

Kusaya shows a high preservability due to the microorganism-derived antibiotics contained in kusaya gravy, which is important for kusaya manufacturing. However, the antimicrobial compounds and its producing bacteria, as well as the antimicrobial activity of the kusaya gravy itself, have remained unknown. In this study, we isolated antibiotic-producing bacteria of the genus Streptomyces from kusaya gravy from Hachijojima and found that they produced antibacterial substances against various fungi and bacteria. In addition, we demonstrated that kusaya gravy itself shows antimicrobial activity, which was consistent with that of the isolates. This is the first report to directly indicate that kusaya gravy contains microorganism-derived antibiotics, which are assumed to be produced by actinomycetes.

24R005A and 24R005B: Novel radical scavengers of DPPH obtained from Streptomyces sp. cultured in a fish powder medium.

We have successfully isolated two novel compounds, 24R005A (1, C13H14O4) and 24R005B (2, C13H13ClO4), from Streptomyces sp. 24R005, using fish (anchovy) powder as a medium. In this study, we evaluated the use of fish (anchovy) powder as a fermentation material for producing bioactive compounds. Spectroscopic analyses revealed that the two compounds share a common skeletal structure. However, each compound contains unique branched side chains. Furthermore, compounds 1 and 2 exhibit moderate radical-scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH), with ED50 values of 200 and 130 µM, respectively.

Design, characterizations, and antimicrobial activity of sustainable home furnishing-based waste fabric treated using biobased nanocomposite.

Clothing and textile industries are major contributors to environmental pollution including textile manufacturing through garment production, spinning, weaving, and dyeing. In this context, the sustainability textile industry is a big challenge and contributes to serving a large segment of society. Also, textile wastes could be used as a raw material for added-value products. Herein, in this study, recycling of residues fabric was treated with antimicrobial nanocomposite to reach the best use of exhausts and obtain multifunction products of aesthetic via the technical design of the waste raw materials. Besides, solving the unemployment problem by opening fields for small industry projects capable of producing high-value textile artifacts, especially when treated against microbes, can be applied to home furnishings. The waste fabric was treated via green synthesis nanocomposite based on chitosan and in situ prepared ZnONPs and cross-linked with tannic acid. The prepared nanocomposite was characterized using physicochemical analysis including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). Additionally, the nanocomposite and treated fabric topographical behavior were studied using scanning electron microscopy (SEM) attachment with energy dispersive X-ray analysis (EDX), and images were processed to evaluate the roughness structure. Additionally, high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS) were performed to ensure the size and stability of the nanocomposite. The obtained results affirmed the green synthesis of nanocomposite with a size around 130 nm, as well as the doped ZnONPs average size of 26 nm and treated waste fabric, performed a promising attraction between nanocomposite and fabric fibers. Moreover, the antimicrobial study observed excellent activity of nanocomposite against bacteria and unicellular fungi as well.