MATERIALS AND METHODS: The produced nanoparticles were characterized using UV-visible spectroscopy. The Bovine Serum Assay (BSA) and Egg Albumin (EA) assays were used to assess the anti-inflammatory effects. The protein denaturation of AgNPs was calculated and compared to a standard to determine the anti-inflammatory activity of green synthesized AgNPs. Using varying concentrations of OGmediated AgNPs in Mueller Hinton Agar (MHA), the antimicrobial effects of OG have been investigated against E. coli, S. aureus, and Pseudomonas sp. Additionally, by measuring optical density, the time-kill curve analysis for E. Coli and S. Aureus has been examined from one hour for up to five hours.
RESULTS: The green synthesized AgNPs were developed successfully using a plant Ocimum gratissimum. The synthesized AgNPs exhibited a maximum absorption peak at 440 nm and SEM analysis revealed that the synthesized AgNPs were spherical and oval. The result findings of the anti-inflammatory activity reveal that AgNPs have great potential when compared to the standard. At the concentration of 50 μg/mL, AgNPs exhibit 76% in BSA assay and 74% in EA assay, where the standard shows 80% inhibition. The antimicrobial activity showed a zone of inhibition around 19mm for E. coli and a 20mm zone of inhibition for S. aureus and Pseudomonas sp., which shows the efficacy of AgNPs. The time-kill assay shows that the optical density of E. coli and S. aureus was reduced to 0.1 after 5 hours of incubation, which shows the potential of green synthesized AgNPs.
CONCLUSION: OG-mediated AgNPs have both antiinflammatory and antimicrobial effects. Anti-inflammatory effects are better when compared to standard drugs. Antimicrobial effects are better for Gram-negative bacteria.
METHODS: Antimicrobial activity was determined with disc diffusion and broth microdilution assays against eight skin colonising microorganisms including Staphylococcus aureus, Staphylococcus epidermidis, Salmonella enterica, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia followed by further fractionation of the pods ethyl acetate fraction by column chromatography along with preparative thin-layer chromatography. Quantification of bacterial death mechanism was elucidated by the measurement of hole size in cell wall that has been induced by extract constituents via field-emission scanning electron microscopy (FESEM).
RESULTS: Four fractions showed significant antimicrobial activity against the six microorganisms tested (p
METHODS: Time-kill analysis of one MRSA reference strain (ATCC 43300) and three clinical isolates (WM3, BM1 and KJ7) for both compounds was first performed to provide the bacteriostatic/bactericidal profile. Then, MRSA ATCC 43300 strain treated with both compounds was interrogated by NGS.
RESULTS: Both stigmasterol and lupeol possessed bacteriostatic properties against all MRSA tested; however, lupeol exhibited both bacteriostatic and bactericidal properties within the same minimum inhibitory concentration and minimum bactericidal concentration values against BM1 (12.5mg/mL). Transcriptome profiling of MRSA ATCC 43300 revealed significant modulation of gene expression with multiple desirable targets by both compounds, which caused a reduction in the translation processes leading to inhibition of protein synthesis and prevention of bacterial growth.
CONCLUSIONS: This study highlights the potential of both stigmasterol and lupeol as new promising anti-MRSA agents.