Health issues involving inadequate treatment of diseases like cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized Silver Nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultra-violet (UV), and Fourier Transform Infrared (FTIR) Spectroscopy. Antimicrobial activity was evaluated in selected gram-positive and gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability was evaluated using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and apoptosis studies in selected human cancer cells. Nanoparticles (NPs) were spherical clusters, with sizes between 40-70 nm. The absorption peak at 375 nm, and the carbodiimide bond confirmed the synthesis and stabilization of tested AgNPs. NPs showed good stability of −23.9 ± 1.02 mV. Strong antimicrobial activity (6-18 mm) was seen in all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 µg/ml, with the highest activity seen against gram-negative Escherichia. coli (18 ± 0.5 mm), and the lowest activity was seen against gram-positive Listeria. monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 µg/ml). They were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested, and low apoptotic indices (< 0.2). These findings indicated that these AgNPs showed great potential as effective anticancer and antibacterial modalities.

Keywords: Anticancer Activity; Antibacterial Activity; Biosynthesis; Silver Nanoparticles, Porous Starch, Cowpea