GREEN SYNTHESIS AND BIOLOGICAL EVALUATION OF GOLD NANOPARTICLES USING AQUEOUS EXTRACTS OF WITHANIA COAGULANS

Abstract

Background: Green synthesis of gold nanoparticles (AuNPs) using medicinal plants offers an eco-friendly and sustainable alternative to conventional nanoparticle production. Withania coagulans contains bioactive phytochemicals with potential reducing, stabilizing, and therapeutic properties. However, the biological activities and safety profile of W. coagulans-mediated AuNPs require further evaluation. This study investigated the green synthesis, characterization, and biological activities of AuNPs synthesized using aqueous extracts of the leaf, stem, and fruit of W. coagulans. Objective: To synthesize and characterize gold nanoparticles (AuNPs) using aqueous extracts of Withania coagulans. Methodology: The method used was to use plant extracts (leaf, stem and fruit) as a natural reducing and stabilizing agent to chloroauric acid. UV–Vis spectroscopy, SEM, TEM, FTIR, XRD and zeta potential analysis were used to assess the AuNPs. Antibacterial, antifungal, antioxidant, anti-inflammatory, antipyretic, cytotoxic and phytotoxic properties were evaluated using in-vitro and in vivo assays. Results: Ruby red AuNPs were obtained, and their surface plasmon peak was found around 550nm. The spherical particles (20-100 nm) were confirmed by SEM and TEM. The antibacterial and antifungal activity of the AuNPs was more potent than the crude extracts; the antioxidant activity was significant; the toxicity to the cells was low and was dose-dependent; antifungal activity was exhibited; and the phytotoxicity to Lemna minor was measurable. AuNPs prepared with W. coagulans showed a promising bioactivity profile along with an acceptable safety profile in line with the trends of sustainable nanotechnology and indicate potential biomedical relevance. Conclusion: W. coagulans-mediated AuNPs demonstrated promising bioactivity with a favourable safety profile, aligning with sustainable nanotechnology trends and suggesting biomedical relevance.