Ocimum gratissimum mediated synthesis of AgNPs - An in vitro analysis of anti-inflammatory and antimicrobial effects.

Introduction: Silver nanoparticles (AgNPs) are effective against almost all kinds of pathogenic organisms. The green synthesis of AgNPs utilizing extracts from medicinal plants is being researched to examine the therapeutic advantages of AgNPs because the chemical production of AgNPs is more toxic. In this study, the stem extract of Ocimum Gratissimum (OG) also known as Karunthulasi or wild basil for green synthesis of AgNPs and evaluating their antiinflammatory and antimicrobial effects.

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.