Green Synthesis of Silver Nanoparticles of Vernonia cinerea Leaf Extract and their In vitro Cytotoxicity Activity against Neuroblastoma SHSY-5Y Cell Lines, Antimicrobial and Antioxidant Studies.

Background: Green syntheses of silver nanoparticles using plant extracts have potential anti- cancer, antimicrobial, and antioxidant properties, among other aspects. The aim of the present patent study was to synthesize silver nanoparticles (AgNPs) using Vernonia cinerea plant extract.

Methods: The AgNPs were successfully prepared and characterized using UV-Vis Spectrophotometer, particle size, Zeta potential, Transmission electron microscopy (TEM), Energy-dispersive x-ray analysis (EDAX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectrometry. The in vitro cytotoxicity study was performed using neuroblastoma SHSY-5Y cell lines. Moreover, antimicrobial and antioxidant activity studies were also performed for AgNPs.

Results: The size of AgNPs determined through the dynamic light scattering (DLS) technique was 49.5 nm and the zeta potential was -36.8 mV. The synthesized AgNPs were checked using UV-Visible spectroscopy at ƛmax 439 nm. The color was changed from green to dark brown, indicating the formation of AgNPs. The TEM study revealed that the nanoparticles were spherical in shape. The XRD pattern of AgNPs produced in this experiment was apparently crystalline. The results of FTIR study revealed that the majority of the obtained peaks correspond to the polyphenols, triterpenoids, and alkaloids which were abundant in the corresponding to the V. cinerea leaf extract and support to the formation of AgNPs. The cytotoxicity effect of the V. cinerea plant extract and biosynthesized AgNPs was found to be dosedependent. From the results of antimicrobial studies, it was reported that the gram negative bacteria were found to be more susceptible compared to the gram positive bacteria. Moreover, the results of antioxidant study revealed that the AgNPs showed good antioxidant activity (77.21%) in comparison to the V. cinerea plant extract (56.13%).

Conclusion: Based on the results, it could be concluded that the green synthesized silver nanoparticles showed promising anticancer, antioxidant, and anti-bacterial activities as compared to the plain V. cineria plant extract.