Bactericidal and Cytotoxic Potential of Silver Nanoparticles Green Synthesized Using Phytochemically Prospected Arachis hypogea Pods

Arachis hypogea or groundnuts are widely consumed nuts as a source of protein and oil. After removal of nuts, empty pods are fed to cattle as fodder. So far, hardly a few articles have reported the detection or isolation of any compound from groundnut pods. The present research work aimed towards qualitative phytochemical analysis of A. hypogea pods, their use in green synthesis of silver nanoparticles, and characterization using modern techniques and evaluation of their antimicrobial activity and cytotoxicity against the breast cancer cell line MCF7. Spectroscopic and chromatographic methods of phytochemical analysis showed the presence of various flavonoids, terpenoids, and iridoids in groundnut pods. These compounds further brought about the reduction of silver nitrate to silver nanoparticles, which on characterization were found to have a spherical/oval shape with an average particle size of 27 nm. On screening, it was observed that they had significant antimicrobial activity (agar well diffusion method) against Gram-positive bacteria than Gram-negative ones and fungal strains, and cytotoxicity against MCF-7 (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assay). Nomarski interference contrast microscopic imaging on staining of silver nanoparticle-treated MCF7 by rhodamine phalloidin and 4′,6-diamidino-2-phenylindole (DAPI) proved the disrupted integrity of actin filaments and chromatin condensation, respectively, within MCF7 cells.