The Healing Paradox: Exploiting Poisonous Holigarna arnottiana Bark for Green-Synthesized Antioxidant and Anticancer Silver Nanoparticles

This study explores the green synthesis of silver nanoparticles (AgNPs) using methanolic bark extract from Holigarna arnottiana, aiming to develop an eco-friendly and efficient method for nanoparticle production. The synthesis was rapidly achieved within 2 h by optimizing key parameters, including silver nitrate concentration, extract concentration, and pH. The resulting H. arnottiana mediated silver nanoparticles (HAgNPs) were characterized using UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD), confirming their spherical shape, crystalline structure, and an average particle size of approximately 77.27 ± 1.14 nm. Antioxidant activity of the HAgNPs was evaluated through the DPPH free radical scavenging assay, showing significant activity with an IC₅₀ value of 232.33 µg/mL. Their anticancer potential was assessed using the MTT assay on PA-1 human ovarian teratocarcinoma cells, revealing a dose-dependent cytotoxic effect with an IC₅₀ value of 216.03 µg/mL. These bioactivities are attributed to the presence of phytochemicals such as glycosides, terpenoids, and carbohydrates in the bark extract, which play key roles in reducing silver ions and stabilizing the nanoparticles. FTIR analysis further supports the involvement of these compounds in nanoparticle formation and biological activity. Overall, this work highlights the potential of H. arnottiana as a valuable source for the green synthesis of bioactive silver nanoparticles, with promising applications in antioxidant and anticancer therapies. The findings provide a foundation for future research into plant-based nanomaterials for biomedical applications.