Green synthesis of silver nanoparticles using Swertia chirayita and their antioxidant and anticancer potential

Nanotechnology is widely explored in biomedical fields, especially for cancer therapy and antioxidant applications. Silver nanoparticles (AgNPs) synthesised using plant extracts offer a green and eco-friendly alternative to chemical methods. While AgNPs have been synthesised from many medicinal plants, there are no prior reports on the biosynthesis of AgNPs from the critically endangered Himalayan herb Swertia chirayita, a phytochemical-rich plant containing unique xanthones, iridoids, and secoiridoid glycosides and their application against lung cancer cells. This study reports, for the first time, the biosynthesis of AgNPs using S. chirayita aqueous extract and evaluates their antioxidant and anticancer potential. AgNPs were characterised by UV-Vis, XRD, FESEM, and EDAX. Antioxidant activity was measured by DPPH assay, while cytotoxicity against A549 lung cancer cells was assessed using MTT assay and AO/EtBr staining to observe apoptosis. AgNPs exhibited an IC₅₀ of 40.61 µg/mL, demonstrating strong antioxidant and apoptosis-inducing anticancer effects.