In Vitro Antioxidant, Antipathogenicity and Cytotoxicity Effect of Silver Nanoparticles Fabricated by Onion (Allium cepa L.) Peel Extract

In this study, we emphasize a rapid and cost-effective biogenic approach for the synthesis of silver nanoparticles (AgNPs) using an aqueous extract of onion (Allium cepa L.) peel (brown skin) acting as a reducing and capping agent. The synthesized AgNPs were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. The morphology of synthesized AgNPs was a spherical shape, cubic structure with an average particle size range of 33-50 nm. The AgNPs have higher antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTs) when compared with ascorbic acid (vitamin C). The synthesized AgNPs have strong antipathogenic activity towards foodborne illness-causing bacterial pathogens of Gram-positive (Bacillus sp., Staphylococcus aureus, and Corynebacterium sp.) and Gram-negative (Escherichia coli, Salmonella sp., and Vibrio cholerae) organisms. Furthermore, the AgNPs have the potential anti-proliferative action on A549 lung cancer cell lines, suggesting a novel chemotherapeutic agent against human lung cancer.