Biological Activities of Selenium Nanoparticles Synthesized from Camellia sinensis (L) Kuntze Leaves

Selenium in the form of selenoproteins is formed through a unique translocation recoding pathway and plays a vital role in human metabolism. Selenium nanoparticles (SeNPs) when synthesized using green synthesis from plant extract offer more advantages than physical and chemical methods. Previous studies have synthesized selenium nanoparticles from green tea and white tea; here, we report the synthesis of selenium nanoparticles from Camillia sinensis (L) Kuntze leaves (black tea) by green synthesis. Moreover, we have tested the antimicrobial and antioxidant activity of the plant extract, SeNPs, and combination of plant extract and SeNPs which have not been previously studied. The antimicrobial efficacy of SeNPs was tested against Klebsiella pneumonia, Candida albicans, and Staphylococcus aureus. They showed inhibitory effects against these organisms individually and in combination with Camellia sinensis leaf extract. The antioxidant properties of SeNPs were checked using FRAP and DPPH assays, where high radical scavenging activity was exhibited by SeNPs and in combination with the plant extract. Furthermore, synthesized SeNPs were examined for cytotoxicity tolerance against Vero cells and their IC₅₀ values determine that plant-mediated SeNPs showed high cytotoxicity at minimal concentrations. If explored further, the reducing, capping, and stabilizing capabilities of SeNPs may demonstrate other inhibitory effects and could be explored for understanding the role of selenium in cellular metabolism.