Biogenic synthesis of silver nanoparticles using Paenibacillus sp. in-vitro and their antibacterial, anticancer activity assessment against human colon tumour cell line

Abstract

Aim: To evaluate the antibacterial and anticancer activities of silver nanoparticles (AgNPs) synthesized from aqueous extract of Paenibacillus sp. strain NS-36. Methodology: The green synthesized AgNPs were characterized by UV-Vis. spectroscopy, Fourier Transform Infrared Spectroscopy, Atomic Force Microscopy, X-Ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and Transmission Electron Microscopy. Antibacterial activity was assessed against pathogenic bacteria by using agar well diffusion method and the anticancer activity was evaluated against Human Colon Tumour-116 cell line using 96 well plate cell proliferation assay. Results: The synthesized AgNPs showed UV-Vis absorbance peak at 416 nm. The characterization analyses revealed the shape as spherical and size ranging from 17.49 to 52.85 nm and the presence of different functional groups and elements that involved in the stabilization and capping. The antibacterial activity revealed that AgNPs have good inhibitory action on pathogens, whereas the results of anticancerous assessment indicated that AgNPs have a dose-dependent activity on the Human Colon Tumour-116 cancer cells and the IC50 value was found to be 81.45ug mr'. Interpretation: The AgNPs exhibited considerable antibacterial activity against bacterial pathogens by rupturing and damaging the cell membrane. The AgNPs release silver ions into the cell once they attached to the cell membrane and disrupt the bacterial DNA replication. The AgNPs are toxic to tumour cells and induce intracellular reactive oxygen species which damage cells. Along with ROS, the rounding and shrinkage of tumour cells caused by AgNPs reduced the % viability of cancer cells.