Biogenic AgNPs synthesized via endophytic bacteria and its biological applications.

In this present study, the endophytic bacteria were isolated from the drought-tolerant ornamental plant Pennisetum setaceum. The biomass of endophytic bacteria was utilized for the biogenic synthesis of silver nanoparticles (AgNPs). The synthesis of AgNPs was confirmed by UV-Visible and FTIR spectroscopy followed by SEM analysis. The antibacterial studies were performed through MIC, MBC, and biofilm assays. Efficacy of AgNPs against the human breast cancer (MCF-7) cells was also tested, and the IC₅₀ was determined by MTT assay. In our study, we have observed that the synthesized AgNPs exhibited a dose-dependent cytotoxicity (1-100 μg/mL) against MCF-7 cells and morphological alterations of the cells were also visualized and the IC₅₀ was observed at 50 μg/mL. The treatment of synthesized AgNPs altered the expression of apoptotic proteins including Bax, Bcl-2, and inflammatory marker COX-2 in MCF-7 cells. To the best of our knowledge, this is the first report that demonstrates the AgNPs from endophytic bacteria isolated from the plant Pennisetum setaceum can induce apoptosis in human breast cancer MCF-7 cells. Our results suggest that AgNPs used in this study can be utilized to control human pathogens and can also be utilized to induce apoptosis in breast cancer cells.