In Vitro Potential and Characterization of Bio Inspired Viola odorata Mediated Silver Nanoparticles

Abstract

Nanotechnology is one of the most promising technologies of the 21st century and has gained a dynamic interest in the field of life sciences. Although conventional chemical approaches have been employed to synthesize nanoparticles, however, they have some adverse effects. To minimize the shortcomings of chemical and physical synthesis of nanoparticles, we cynosure on green synthesis of silver nanoparticles (AgNPs). AgNPs were synthesized from aqueous leaf extract of Viola odorata commonly known as Gul-ebanafsha. Several techniques including Ultra Violet Visible Spectroscopy (UV-VIS), Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Crystallography (XRD), Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM) were used for the characterization of biosynthesized NPs. UV-VIS spectroscopy showed highest peak at 430nm, which confirmed formation of AgNPs. XRD pattern confirmed crystalline structure of NPs with average size of 11nm. FTIR showed capping of NPs with phytochemicals present in leaf extract of Viola odorata, which acts as reducing and stabilizing agent in NPs formation. Particle size distribution and zeta potential were analyzed by DLS. SEM revealed irregular shape in morphology. Furthermore, different biological activities have been done and the highest antioxidant activity recorded as 73.5%, 70.04%, and 78.3% at 200μg/ml for 2,2-diphenyl 1-picrylhydrazyl (DPPH), total reducing potential (TRP), and total antioxidant capacity (TAC), respectively. Highest hemolysis activity (6.9%) and brine shrimp cytotoxicity (60%) of AgNPs were observed at 200μg/ml. Cytotoxicity of AgNPs against liver cancer cell line (HepG2) was analyzed through Suforhodamine B assay and the results showed cell viability reduced to 35%, whereas for positive control (DOX), cell viability was recorded 40%. Green synthesized AgNPs also showed broad spectrum antibacterial and antifungal activity against various pathogenic strains. Zone of inhibition for gram negative strains (Escherichia coli, Pseudomonas aeruginosa, and Klebseilla pneumonia) was higher in comparison with gram positive strains (Staphylococcus epidermidis and Bacillus subtilis). This may be due to change in composition of cell wall. Our result suggested that AgNPs synthesized in this study are more compatible and have high anticancer activity and can be used for cancer therapy, drug delivery agent and other clinical products however further study is required to investigate and evaluate the effects of AgNPs in animal models.