Green synthesis and characterization of alfalfa (Medicago sativa) leaves extract capped silver nanoparticles (MSL@AgNPs): Antibacterial, antifungal, antioxidant, catalytic, and cytotoxic activities

Background and Aim : Nowadays, nanoparticles are used effectively for targeted drug delivery, diagnosis, treatment of various diseases including heart disease, wound healing and antimicrobial compounds. The aim of this study was to obtain a suitable method for the green synthesis of silver nanoparticles using alfalfa extract and to investigate its antibacterial, antifungal, anticancer, antioxidant and catalytic properties of it.Methods : Using a nontoxic, low-cost and rapid approach in presence of alfalfa (Medicago sativa) leaves extract, green silver nanoparticles were synthesized as MSL@AgNPs and characterized in terms crystalline, morphology and structural with XRD, EDS, FESEM, TEM, FT-IR, DLS and UV-Vis techniques. Antimicrobial activities of AgNPs was assessed using MIC, MBC and MFC on standard strains of Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Candida albicans. The antioxidant activity was calculated by scavenging free radicals of DPPH. The cytotoxic effects were assessed on human fibroblasts using MTT staining method. To assess the catalytic feature, photocatalytic activity for the degradation of the methylene blue (MB) and methyl orange (MO) was applied.Results : FESEM, TEM and XRD analysis results revealed that the product was homogeneous, uniformly, spherical-like morphology regular and small size with face-centered cubic structure. MSL@AgNPs showed strong antimicrobial effects against the tested microorganisms. The antioxidant results revealed that with increasing the concentration of nanoparticles, the percentage of DPPH inhibition increases (۲۵% to ۷۸%). Treatment of human fibroblasts with different concentrations of the nanoparticles for ۲۴ hours showed that the cytotoxicity of synthesized silver nanoparticles was dose-dependent and at concentrations of ۵۰ and ۱۰۰ ?g/ml showed the most cytotoxic effects and the amount of inhibitory concentration (IC۵۰) showed ۱۸.۲۲ ?g/ml. Furthermore, the biosynthesized AgNPs exhibited a highly significant photocatalytic activity for the degradation of MB and MO.Conclusion : For the first time, we synthesized silver nanoparticles in presence of alfalfa leaves extract with strong antimicrobial, anticancer, antioxidant and catalytic features applicable in medicine and pharmacological industry.

کلیدواژه ها:

Silver nanoparticles ، Antibacterial ، Antifungal ، cytotoxic ، antioxidant ، Medicago sativa