Assessment of antibacterial, antioxidant and cytotoxic potential of green synthesis of silver nanoparticles by extracts of Allium akaka S.G. Gmelin

Applications of nanotechnology in different areas of research have expanded over the last years. Silver nanoparticles (Ag-NPs) have beneficial effects as antioxidants, antibacterial, and anticancer [۱-۲]. Valak is a native vegetable of Iran that includes several species of melanocrommyum subgenus belong to the Allium genus. Their fresh leaves are consumed as vegetable. Their fresh and onions are used in pilaf. The aims of the present work were to study the possible green synthesis of Ag-NPs using Allium akaka S.G. Gmelin aqueous leaves extract as a reducing agent; to characterize them, to investigate the antibacterial, antioxidant potency and cytotoxic potential of these biosynthesized Ag-NPs. The obtained nanoparticles were characterized using UV-Vis, FT-IR, XRD, and TEM. The antioxidant potential was evaluated by ۲,۲-- diphenyl-۱-picrylhydrazyl (DPPH۰) free radical scavenging assay. Disc diffusion method was used to evaluate the antibacterial activity of Ag-NPs against Escherichia coli and Staphylococcus aureus. Cytotoxic activity of biosynthesized Ag-NPs was tested against human cervical carcinoma cell line (HeLa). Results of characterization showed that Ag-NPs were regular spherical in shape, with average diameter of ۴۰ nm. The green synthesized Ag-NPs exhibited good antioxidant and antibacterial potential. Cytotoxicity test revealed that green synthesized Ag-NPs had inhibitory activity against cancer cell line (HeLa) which was concentration dependent. Accordingly, the treatment of (HeLa) cancer cell line cells according to over ۲۴ hours revealed that the cytotoxicity of the aqueous extract and synthesized nanoparticles are dose-dependent, with the IC۵۰ value was equal to ۵۲.۳۲ and ۵۱.۷۶ μg/ml respectively. In fact, Plant crude extract contains novel secondary metabolites such as phenolic acid, flavonoids, alkaloids and terpenoids in which these compounds are mainly responsible for the reduction of ionic into metallic nanoparticles formation. Ag-NPs were successfully synthesized from Allium akaka S.G. Gmelin leaves extract, which acts as reducing, capping, and stabilizing agents in the process. The synthesis procedure was simple, low cost, and eco-friendly. Finally, green synthesis of silver nanoparticles proved to be an ideal potential candidate for the medical application where antibacterial and anticancer activity is essential.

کلیدواژه ها:

Allium akaka S.G. Gmelin ، Silver nanoparticles ، HeLa cancer cell line ، Escherichia coli ، Antioxidant activity.