Significant Zone Of Inhibition Research Articles

Analysis of Photochemical and Antibacterial Activity of Gooseberry Leaf Extract (Phyllanthus acidus L. Skeels) for Formulation of Fortified Broiler Feed

The aim of the research was to assess the phytochemical composition, total flavonoid content and antibacterial activity of Phyllanthus acidus leaf extract (PALE). The study utilized the disc diffusion method to test the in vitro antibacterial properties of the extract against Escherichia coli and Lactic Acid Bacteria. The data collected were analyzed using analysis of variance and significant differences were further analyzed using Duncan's multiple range test. The results of the study showed that PALE contains bio-active compounds such as alkaloids, flavonoids, tannins and steroids. The total flavonoid content was 663.92 µg/ml QE. PALE exhibited statistically significant inhibition zone against both pathogenic and non-pathogenic bacterial species compared to the standard antibiotic zinc bacitracin. The extract at 2% concentration produced the highest inhibition zone compared to the 1.5% and 1% concentrations, but its effect was significantly lower than that of the control antibiotic zinc bacitracin. Based on these findings, it was concluded that PALE has the potential to be used as an antimicrobial feed additive in broilers. However, further research is necessary to investigate its efficacy in vivo and to determine its safety and potential side effects.

Bactericidal significance of aqueous extracts of Jatropha tanjorensis on Salmonella isolates from domestic chicken coops; Ayurveda and Universal health coverage

Multidrug resistance is more significant among other public health challenges in Nigeria. Many plants have been investigated to have antimicrobial effects on panels of microorganisms including multidrug-resistant pathogens. This study explored the antimicrobial potency of Jatropha tanjorensis on Salmonella isolates from domestic chicken coops. Wet and dried fecal samples of Chicken were obtained from chicken coops. Fecal samples and medicinal plants of interest were analyzed using standard microbiological techniques and procedures. The aqueous concentration of extracts from this research included 0.2 g-10 ml, 0.5 g-10 ml, 1 g-10 ml, 1.5 -10 ml, and 2 g-10 ml. Results of this study indicated that extracts of dried leaves showed more antimicrobial effects than fresh leaf extracts as significant zones of inhibition of 10 mm, 14 mm, 19 mm and 28 mm were observed for dried leaf extract concentrates of 0.5 g-10 ml, 1.0 g-10 ml, 1.5 -10 ml, and 2 g-10 ml respectively. Corresponding zones of inhibition of 9 mm, 11 mm and 20 mm were seen for fresh leaf extract concentrates of 1.0 g-10 ml 1.5 g-10 ml and 2.0 g-10 ml. Owing to their antimicrobial effectiveness, availability, and inexpensive qualities, traditional medicines should be integrated with allopathic medicines if Nigeria must achieve universal health coverage in Nigeria. Plant extracts possess extensive antimicrobial activities against many microorganisms. Hence, more plants' clinical toxicity and safety need to be investigated.

Underwater adhesion and curing of superhydrophobic coatings for facile antifouling applications in seawater

Superhydrophobic coating is a promising candidate to resolve the marine fouling. However, the immobilization and curing of the coatings in seawater is a signification challenge in the practical applications. Herein, a superhydrophobic and antibacterial membrane was fabricated, and its immobilization on substrates was realized directly in seawater via the underwater adhesion technology. The obtained membranes displayed good flexibility, mechanical strength (1.56 MPa), and hydrophobicity. After the curing in seawater, they can lift a 200 g load without any separation, intuitively indicating the excellent adhesion force with substrates, and the adhesion strength reached up to 3.63 MPa. The WCA and SA values were 161.3° and 4.9°, respectively. Furthermore, these properties still maintained steady after the 30 days of immersion in seawater, showing their long service life. The self-cleaning test and the significant inhibition zones demonstrated their excellent resistance to the adhesion and the multiplication of marine microorganisms. More importantly, this developed method can be used in other substrates to obtain the antifouling coatings in seawater, and has universal applicability in the ocean engineering.

Biomimetic formation of silver oxide nanoparticles through Diospyros montana bark extract: Its application in dye degradation, antibacterial and anticancer effect in human hepatocellular carcinoma cells

ObjectivesRemarkable potential of silver nanoparticles (NPs) makes its use efficient in both biological as well as industrial applications. Post harvested NPs, free from other hazards chemicals will be ideal for biological applications. Thus, plant mediated biological method is much focused than the available approaches. MethodsThe present work focusses on fabrication of silver oxide NPs (Ag2ONPs) using methanolic bark extract of Diospyros montana and characterized through sophisticated analytical techniques. ResultsUV–Vis indicated Ag2ONPs formation, FTIR analysis identified the functional groups, XRD investigation depicted the face centered cubic crystalline nature, XPS study determined the chemical state, EDX confirmed the purity, spherical shaped and ∼ 10–50 nm size, was evidenced by SEM and TEM respectively. Zeta potential denoted the stability of Ag2ONPs. Photocatalytic degradation of methylene blue was observed. Ag2ONPs showed significant anticancer effect against hepatocellular carcinoma cells (Hep G2), which is mediated through increased DNA damage, & autophagy and decreased mitochondrial membrane potential. The synthesized Ag2ONPs revealed significant zone of inhibition in gram-negative (Escherichia coli − 16.33 ± 2.57 and Pseudomonas aeruginosa-18.56 ± 1.57) and positive (Bacillus subtilis-22.26 ± 4.47, Staphylococcus aureus 18.65 ± 3.15) bacteria at 40 µg/mL of Ag2ONPs exhibiting its antibacterial property. ConclusionsThis enlightens the synthesis of pure and stable Ag2ONPs by green synthesis unwrapping their pharmacological properties which may play a vital role in nanomedicine anchoring its therapeutic efficiency.

Green synthesis of silver nanoparticles from aqueous extract of leaves of Azadirachta indica, its phytochemical screening and antibacterial activity

Silver nanoparticles are gaining importance on account of its antimicrobial properties and low toxicity to humans. The present study was conducted to synthesise silver nanoparticles (AgNPs) from aqueous extract of neem leaves. The phytochemical screening of the aqueous extract of neem leaves was also performed for determining its active principles. The qualitative phytochemical screening revealed that the aqueous extract of neem leaves contained phytochemicals like steroids, alkaloids, phenolic compounds, tannins, flavonoids, saponins and terpenoids. The AgNPs synthesised were characterised using X-ray diffraction analysis which revealed that synthesised AgNPs were face centred, cubic and crystalline in nature and the sample contained silver nanoparticles in a high concentration. The antibacterial activity of the green AgNPs against E. coli isolates including the reference strain was tested and observed that the AgNPs exhibited antibacterial activity though a significant zone of inhibition was not obtained. Based on the results obtained, it could be concluded that silver nanoparticles could be efficiently synthesised from neem leaves and could be utilised in various fields especially in nanotechnology.

Anomalous catalytic and antibacterial activity confirmed by molecular docking analysis of silver and polyacrylic acid doped CeO2 nanostructures.

This research presents the novel synthesis of CeO2 nanostructures (NSs) doped with a fixed amount of capping agent (polyacrylic acid-PAA) and different concentrations (0.01 and 0.03) of silver (Ag). This work aimed to examine the catalytic and antibacterial efficacy with evidential molecular docking analysis of Ag/PAA doped CeO2. Systematic characterization was used to analyze the effect of Ag and a capping agent on crystal structure, morphology, absorbance wavelength, and the exciton recombination rate of CeO2. The silver metal and capping agent (PAA) were added into CeO2 to reduce the size of NSs, enhancing the catalytic efficacy. These binary dopants (Ag-PAA) based CeO2 revealed remarkable results for catalytic de-colorization of rhodamine B dye and antimicrobial potential as the dopants provide more active sites. Notably, (0.03) Ag/PAA doped CeO2 NSs exhibited a substantial catalytic reduction (98.9%) of rhodamine B dye in an acidic medium. The higher doped CeO2 revealed a significant inhibition zone (3.75 mm) against Escherichia coli at maximal concentration. Furthermore, in silico docking showed the possible inhibitory impact of produced nanomaterials on the fatty acid biosynthesis enzymes FabI and FabH.

An Approach to Antifungal Efficacy through Well Diffusion Analysis and Molecular Interaction Profile of Polyherbal Formulation

In the current scenario, there is a thirst for research against emerging microorganisms, and it becomes challenging to introduce new drugs against organism virulence are pretty interesting. Herbal medicines are now gaining popularity as a treatment option for various diseases worldwide. The present study analyzes the antifungal effect of a polyherbal formulation through in vitro well diffusion method using fungal strains such as Candida albicans, Aspergillus niger, Aspergillus fumigatus, Cryptococcus neoformans, and Sporothrix schenckii. Molecular docking is done using the Auto dock vina tool to predict the mechanism of action of the phytomolecules present in the polyherbal formulation. The molecular interactions are visualized using molecular modelling (PyMOL) software. The antifungal effect was observed in a concentration-dependent manner with a significant zone of inhibition. Also, phytomolecules in polyherbal formulation showed potential inhibition on CYP450 Lanosterol 14 α-demethylase 1, 3 β-Glucan synthase, and Thymidylate synthase from docking analysis.

Screening and identification of candidate therapeutic drugs from plants for the management of patients infected bacterial infection associated with SARS COV-2

The emergence of COVID-19 (SARS-COV-2) has resulted in millions of deaths worldwide. Nigeria has recorded over 2000 deaths due to the disease. Development of alternative medicine from plants against SARS-COV-2 can be a potential therapy for treatment of secondary complications. To investigate plants with potential to manage respiratory tract infections. The plants were extracted and screened for phytochemical constituents; their acute and subacute toxicity profile was evaluated. The plant extracts were tested against clinical microbial isolates associated with respiratory tract infection. All the plants extract were found to have acute toxicity dose above 5000 mg per kg body weight. Among the four tested medicinal plants Guiera senegalensis was found to have significant zone of inhibition against Klebsiella pneumonia and Moraxella catarrhalis more than the standard drug (Gentamicin). Guiera senegalensis has been used in traditional medicine to treat bacterial infections without any report of toxicity. The preclinical study indicated that Guiera senegalensis can be used in the management of respiratory infections associated with symptoms of COVID 19. Guiera senegalensis can therefore be used as a potential medicinal plant for management of secondary bacterial infections in Covid19 patients.

Synthesis and characterization of ZnO nanomaterial from Cassia sieberiana and determination of its anti-inflammatory, antioxidant and antimicrobial activities

Utilization of plant extracts for the synthesis of nanomaterials is a green technology that is safe to the environment. In the current study, zinc oxide nanoparticles (ZnO NPs) was synthesised using the methanolic root bark extract of Cassia sieberiana as capping and stabilizing agents for the first time. The ZnO NPs were then characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), UV–Vis spectroscopy, transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). Anti-inflammatory and antioxidant activity of the nanoparticles were analyzed by egg albumin (EA) denaturation assay and DPPH free radical scavenging assay respectively. The agar well diffusion method was also used to access the antimicrobial activity of the ZnO NPs against S. aureus (gram-positive), E. coli (gram-negative), S. typhi (gram-negative) and C. albicans (yeast). Saponins, anthracenosides, triterpenes and polyphenols were the phytochemicals present in the plant extract. The average particle size (TEM) determined was 12.9 ± 3.1 nm with spherical shapes. ZnO NPs demonstrated good antioxidant activity (IC50 = 0.480 ± 0.018 mg mL−1) and dose-dependently inhibited the heat-induced denaturation of egg albumin (IC50 = 0.676 ± 0.000 mg mL−1). In general, the synthesized ZnO NPs showed a positive anti-microbial activity against the selected microbes. The ZnO NPs showed a significant zone of inhibition for S. typhi (20.0 mm), S. aureus (24.0 mm), whereas the zone of inhibition was less for E. coli (13.7 mm) and C. albicans (11.7 mm) at 25 mg/mL. The green synthesized ZnO NPs may be used as an effective drug delivery system.

Nanocomposites containing ZnO-TiO2-Chitosan and berbamine promote osteoblast differentiation, proliferation, and calcium mineralization in MG63 osteoblasts

Recently, biomedical research has focused on bio-nanocomposites that are capable of regeneration of tissues, as well as treating osteomyelitis, osteosarcoma, and other diseases with therapeutic medications. A novel osteoconductive nanocomposite will be synthesized and used to enhance the mineralization of injured bone tissues, as well as their antimicrobial properties. The unique structural characteristics of ZnO-TiO2-Chitosan-berbamine nanocomposites have been described by UV-Vis, PL, FTIR, XRD, FESEM, and HR-TEM experiments, while antimicrobial activity against pathogenic microorganisms has been evaluated by the agar well diffusion method. MTT assays and levels of ALP enzymes were used to test nanocomposites on osteosarcoma cell lines (MG-63) and to assess the osteosarcoma cell line's physical characteristics, bioactivity, and calcium deposition by staining with Alizarin Red S. In addition to showing significant Zones of Inhibition (ZOI) against bacterial and fungal strains, structural characterization revealed the antimicrobial properties of ZnO-TiO2-Chitosan-berbamine composites. According to research conducted on osteoblast-like MG-63 cells grown on ZnO-TiO2-Chitosan-berbamine composites, the composites do not cause toxicity and significantly increase osteoblast proliferation, ALP activity, calcium deposition, and bone growth, making ZnO-TiO2-Chitosan-berbamine a potential therapy for bone-related diseases. Understanding the druggable mechanism of ZnO-TiO2-Chitosan-berbamine will require further studies in the future, including in vivo testing and clinical trials.

EVALUATION OF THE IMPACT OF VARIOUS EXTRACTS OF Swertia chirata ON ANTIMICROBIAL-RESISTANT STRAINS OF PATHOGENS

In several Asian nations, as well as other regions of the world, the plant Swertia chirata is commonly utilized as a herbal remedy. The current study aimed to assess Swertia chirata's impact on a range of antimicrobial-resistant bacteria. To achieve this, the plant's leaves and stems were extracted using ethanol and methanol. Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were used as test organisms. The agar well diffusion method was utilized to determine the antibacterial activity and calculate the Minimum Inhibitory Concentration (MIC). Using the broth dilution procedure, MIC was determined. Bacterial sp. demonstrated a significant zone of inhibition against all extracts out of all the strains. Methanol and ethanol were employed as controls. The results indicated that the ethanol extract of the stem and leaves was superior to the methanol extract in terms of its ability to the methanol extract

Phyto-Extract-Mediated Synthesis of Silver Nanoparticles (AgNPs) and Their Biological Activities.

Nanotechnology finds broad applications in the field of nanomedicine, an emerging new field used for diagnosis, treatment, prevention of diseases, and improvement of health. To synthesize silver nanoparticles (AgNPs) from Withania somnifera and Fagonia indica and to carry out their antimicrobial, insecticidal, and phytotoxic activities, a step toward the new range of nanomedicines. Silver nanoparticles were synthesized from Withania somnifera and Fagonia indica by chemical reduction method, and further biological activities of these nanoparticles were compared with crude methanolic extract, prepared through cold maceration process, at the concentration of 50 mg/ml. Among all tested bacterial pathogens, crude extract of W. somnifera showed a statistically high significant inhibition zone in millimeter against Pseudomonas aeruginosa (21; p < 0.01). AgNPs showed highly significant result against Streptococcus pneumonia (14; p < 0.01). In comparison with crude extracts, AgNPs showed statistically significant (p < 0.01) results against S. pneumonia (AgNPs, 14; crude, 8.33 mm). Crude extract showed significant inhibition zone against two bacterial strains, P. aeruginosa (crude, 21; AgNPs, 11.67 mm) and Klebsiella pneumoniae (crude, 11.33; AgNPs, 8 mm). Crude extracts of F. indica showed the significant activity against Vibrio cholera (p < 0.01; 11.33 mm). Silver nanoparticles of F. indica exhibited the highest significant activity against Aspergillus flavus and Fusarium oxysporum while AgNPs of W. somnifera were active only against A. flavus. Extracts of W. somnifera and F. indica showed increasing phytotoxic activity with increasing concentrations. The highest significant inhibition was obtained for crude extract (46.7) and AgNPs (45.7) of F. indica at 1000 μg/ml. Insecticidal activity of crude and AgNPs of both plants showed significant inhibition against all tested insects with increasing time intervals, and the highest significant result was obtained at 72 hours with a value of p < 0.01 except T. castaneum. Both crude and AgNPs showed potent activity; however, in comparison, silver nanoparticles showed slightly enhanced activity. Crude and AgNPs of both plants showed good phytotoxic and insecticidal inhibition. Antimicrobial studies of AgNPs on diseases causing pathogens open a door for new antimicrobial agents and could be the answer to antibiotic resistance after further analysis.

In Vitro Antibacterial Activity of Green Synthesized Silver Nanoparticles Using Mangifera indica Aqueous Leaf Extract against Multidrug-Resistant Pathogens.

An estimated 35% of the world's population depends on wheat as their primary crop. One fifth of the world's wheat is utilized as animal feed, while more than two thirds are used for human consumption. Each year, 17-18% of the world's wheat is consumed by China and India. In wheat, spot blotch caused by Bipolaris sorokiniana is one of the major diseases which affects the wheat crop growth and yield in warmer and humid regions of the world. The present work was conducted to evaluate the effect of green synthesized silver nanoparticles on the biochemical constituents of wheat crops infected with spot blotch disease. Silver nanoparticles (AgNPs) were synthesized using Mangifera indica leaf extract and their characterization was performed using UV-visible spectroscopy, SEM, XRD, and PSA. Characterization techniques confirm the presence of crystalline, spherical silver nanoparticles with an average size of 52 nm. The effect of green synthesized nanoparticles on antioxidative enzymes, e.g., Superoxide dismutase (SOD), Catalase (CAT), Glutathione Reductase (GR), Peroxidase (POX), and phytochemical precursor enzyme Phenylalanine Ammonia-Lyase (PAL), and on primary and secondary metabolites, e.g., reducing sugar and total phenol, in Bipolaris sorokiniana infected wheat crop were studied. Inoculation of fungal spores was conducted after 40 days of sowing. Subsequently, diseased plants were treated with silver nanoparticles at different concentrations. Elevation in all biochemical constituents was recorded under silver nanoparticle application. The treatment with a concentration of nanoparticles at 50 pp min diseased plants showed the highest resistance towards the pathogen. The efficacy of the green synthesized AgNPs as antibacterial agents was evaluated against multi drug resistant (MDR) bacteria comprising Gram-negative bacteria Escherichia coli (n = 6) and Klebsiella pneumoniae (n = 7) and Gram-positive bacteria Methicillin resistant Staphylococcus aureus (n = 2). The results show promising antibacterial activity with significant inhibition zones observed with the disc diffusion method, thus indicating green synthesized M. indica AgNPs as an active antibacterial agent against MDR pathogens.

Development and Characterization of Chitosan and Chondroitin Sulfate Based Hydrogels Enriched with Garlic Extract for Potential Wound Healing/Skin Regeneration Applications.

Hydrogels can provide instant relief to pain and facilitate the fast recovery of wounds. Currently, the incorporation of medicinal herbs/plants in polymer matrix is being investigated due to their anti-bacterial and wound healing properties. Herein, we investigated the novel combination of chitosan (CS) and chondroitin sulfate (CHI) to synthesize hydrogels through freeze gelation process and enriched it with garlic (Gar) by soaking the hydrogels in garlic juice for faster wound healing and resistance to microbial growth at the wound surface. The synthesized hydrogels were characterized via Fourier-transform infrared spectroscopy (FTIR), which confirmed the presence of relevant functional groups. The scanning electron microscopy (SEM) images exhibited the porous structure of the hydrogels, which is useful for the sustained release of Gar from the hydrogels. The synthesized hydrogels showed significant inhibition zones against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, cell culture studies confirmed the cyto-compatibility of the synthesized hydrogels. Thus, the novel hydrogels presented in this study can offer an antibacterial effect during wound healing and promote tissue regeneration.

Bacillus thuringiensis CHGP12 uses a multifaceted approach for the suppression of Fusarium oxysporum f. sp. ciceris and to enhance the biomass of chickpea plants.

Bacillus species synthesize antifungal lipopeptides (LPs) making them a sustainable and eco-friendly management option to combat Fusarium wilt of chickpea. In this study, 18 endophytic Bacillus strains were assessed for their antifungal activity against Fusarium oxysporum f. sp. ciceris (FOC) associated with Fusarium wilt of chickpea. Among them, 13 strains produced significant inhibition zones in a direct antifungal assay while five strains failed to produce the inhibition of FOC. Bacillus thuringiensis CHGP12 exhibited the highest inhibition 3.45 cm of FOC. The LPs extracted from CHGP12 showed significant inhibition of the pathogen. Liquid chromatography-mass spectrometry (LC-MS) analysis confirmed that CHGP12 possessed the ability to produce fengycin, surfactin, iturin, bacillaene, bacillibactin, plantazolicin, and bacilysin. In an in vitro qualitative assay CHGP12 exhibited the ability to produce lipase, amylase, cellulase, protease, siderophores, and indole 3-acetic acid (IAA). IAA and gibberellic acid (GA) were quantified using ultra-performance liquid chromatography (UPLC) with 370 and 770 ng mL-1 concentrations of IAA and GA respectively. Furthermore, the disease severity showed a 40% decrease over control in CHGP12 treated plants compared to the control in a glasshouse experiment. Moreover, CHGP12 also exhibited a significant increase in total biomass of the plants namely, root and shoot growth parameters, stomatal conductance, and photosynthesis rate. In conclusion, our findings suggest that B. thuringiensis CHGP12 is a promising strain with high antagonistic and growth-promoting potential against Fusarium wilt of chickpea. © 2022 Society of Chemical Industry.

Synergistic antibacterial effect of ethanolic extract of Carica papaya and Psidium guajava leave extract on Salmonella typhi, Escherichia coli and Klebsiella pneumoniae

This study assessed the synergistic antibacterial effect of ethanol extract of Carica papaya and Psidium guajava on Salmonella typhi, Escherichia coli and Klebsiella pneumoniae using agar well diffusion method and microdilution with Microtitre plates. Qualitative phytochemical analysis of the extract reveals the presence of alkaloids, saponins, glycosides, steroids, soluble carbohydrates and phenols. Five (5) grams of the freeze-dried extract was dissolved in 10ml of 10% Dimethyl Sulphoxide (DMSO) and used for sensitivity against selected standard isolates. Upon sensitivity testing, this study observes a significant inhibition zone diameter at the highest concentration of the extract (500 mg/ml) against Klebsiella pneumoniae with an inhibition zone diameter of 31.0mm relative to the inhibition zone diameters of Escherichia coli and Salmonella typhi with (19.5 mm) and (20.5 mm) respectively. The inhibition zone diameters of the positive control (ciprofloxacin solution) at 500 mg/mL for Klebsiella pneumoniae, Escherichia coli and Salmonella typhi was 36.0 mm, 37.5 mm and 34.5 mm respectively. Escherichia coli has minimal inhibitory concentration (MIC) of 0.977 mg/ml while Klebsiella pneumoniae and Salmonella typhi have their minimal inhibitory concentration (MIC) at 31.25 mg/ml and 62.5 mg/ml respectively.

Green Synthesis, Characterization and Antimicrobial Activity of Silver Nanoparticles Using Uraria picta Leaves Extract

Background: The rapid synthesis and antimicrobial activity of silver nanoparticles (AgNPs) synthesized using Uraria picta extract were investigated in this paper, and AgNPs were examined for antimicrobial activity against a variety of pathogenic organisms, including bacteria and fungi. Objective: The main objective was to synthesize AgNPs from Uraria picta leaves extract by the technique of green synthesis for antimicrobial evaluation against bacteria and fungi using MIC studies. Methods: The AgNPs were formed by treating an aqueous extract of Uraria picta leaves with silver nitrate (1 mM) solution, and then nanoparticles were synthesized for various studies. Results: The Uraria picta leaves extract can be used for the green synthesis of AgNPs effectively. The absorption band at 425 nm in the UV-Vis spectrum confirmed the synthesis of AgNPs. According to MIC tests, silver nanoparticles exhibited antimicrobial and antifungal properties. This work will provide a better understanding of the development of new antimicrobial and antifungal activities. Conclusion: We utilized Uraria picta aqueous leaves extract to develop a fast, cost-effective, ecofriendly, and simple method for the synthesis of AgNPs, and the nanoparticles synthesized by this plant for the first time demonstrated antimicrobial activity. AgNPs were observed to be spherical and oval in shape, with average particle sizes ranging from 12.54 to 25.58 nm. The antimicrobial activity of AgNPs was confirmed against typhi, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus by a significant zone of inhibition.

Cytotoxicity and antibacterial effects of silver doped zinc oxide nanoparticles prepared using fruit extract of Capsicum Chinense

Phyto-mediated nanoparticles (NPs) have attracted great attention in recent times due to their unique properties such as high biocompatibility, eco-friendliness, and cost-effectiveness. In this study, silver- zinc oxide nanoparticles (Ag/ZnO-NPs) were prepared using the fruit extract of Capsicum Chinense. The results obtained from both structural, and optical characterization of the nanoparticles confirmed the purity of the composites and their high crystallinity. The nanoparticles exhibited two absorption peaks at 376 and 258 nm with a bang gap energy of 3.53 eV, and the nanoparticulate size of the materials exhibited antibacterial and cytotoxic activities. The Ag/ZnO-NPs exhibited better proliferative activity against HEK 293 cells than HeLa cells. The antibacterial study showed that both the pristine and the composite nanoparticles (ZnO and Ag/ZnO-NPs) have high bactericidal effect on all tested bacterial pathogens, with Ag/ZnO-NPs displaying better antibacterial activity. Cytotoxicity studies showed a dose-dependent proliferative relationship between Ag/ZnO-NPs and tested cancer cells (HEK 293 and HeLa). Antibacterial results showed significant zones of bactericidal inhibition for all tested bacterial pathogens using the biosynthesized ZnO and Ag/ZnO-NPs. These findings demonstrated two-fold applications of biosynthesized Ag/ZnO-NPs, as anticancer and antibacterial agents.

Isolation and screening of lovastatin-producing endophytic fungi from lemongrass (Cymbopogon nardus)

Abstract. Rahmi Z, Yurnaliza Y, Hastuti LDS. 2022. Isolation and screening of lovastatin-producing endophytic fungi from lemongrass (Cymbopogon nardus L.). Biodiversitas 23: 4189-4194. Fungi have long been studied for their cholesterol-lowering compounds, known as statins and the derivatives through fermentation in laboratory investigations. Therefore, this study aimed to isolate and screen endophytic fungal strains from lemongrass capable of producing lovastatin. Endophytic fungi were isolated from the stems and leaves of lemongrass (Cymbopogon nardus) and the selection of their ability to produce lovastatin was assayed using three approaches, namely negative test against Candida albicans, measurement based on absorbance at a wavelength (?) of 230 nm or colorimetric assay, and observation using thin layer chromatography (TLC). A total of 22 endophytic fungi, 15 from the leaves and 7 from the stems were isolated from lemongrass. The capability to produce lovastatin was confirmed using three approaches, resulting in three potential fungal strains, namely Trichoderma sp. CNB 2.5.3, unidentified fungus CND 2.5.4, and Nigrospora sp. CND 2.1.1. Based on the colorimetric assay, the potential strains produced a significant zone of inhibition against C. albicans, with greater lovastatin levels than the other isolates. The TLC analysis showed that the fungal ethanolic extracts contained crude lovastatin as indicated from the same retention factor (Rf) value as standard lovastatin. The presence of lovastatin-producing endophytic fungi can be investigated progressively for optimum production through fermentation and evaluation of its cholesterol-lowering activity in the future.

PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL ANALYSIS OF AQUEOUS EXTRACTS OF WILD MANGO VARIETIES

Phytochemical screening and antibacterial activity of aqueous extracts of bark and leaf of eighteen mango varieties growing in the village Hanavadi, Malavalli taluk, Mandya district, Karnataka state were conducted. They showed the presence of alkaloids, steroids, flavonoids, tannins, cardiac glycosides, saponnins, resins, carbohydrates and proteins. Antibacterial activity tested against six human pathogens- Escherichia coli, Enterobacter aerogenes, Staphylococcus aureus, Streptococcus mutans, Pseudomonas aeruginosa and Bacillus subtilis, by disc diffusion method showed significant inhibition zone against pathogens compared to control. These results disclose the inhibiting property of leaf and bark of wild varieties of mangoes against potential pathogens and thus can be subjected to further investigations for their applications in human phytomedicines.