Thermal Co-reduction engineered silver nanoparticles induce oxidative cell damage in human colon cancer cells through inhibition of reduced glutathione and induction of mitochondria-involved apoptosis

Abstract

Silver nanoparticles (AgNPs) are being commercialized in a number of consumer products including food and cosmetics where there is a direct exposure of AgNPs to human body. An extensive toxicological evaluation is necessary to understand the mechanism for its safe use, since the toxicity effect varies greatly with the synthesis protocol followed. In this study, we report the detailed toxicological analysis of AgNPs fabricated by thermal co-reduction approach. Our study was analysed in human colon cancer cell line (HCT 116) and the IC₅₀ was calculated as 28.11 μg/ml. It was also observed that AgNP induces oxidative stress on HCT116 by increased levels of lipid peroxidation and reduced levels of glutathione. Mitochondrial membrane depolarization was also analysed and Western blot analysis confirms the increased level of Bcl and Caspase-3 which indicates the mitochondrial -mediated apoptosis. Additionally, flow cytometric analysis suggests cell cycle arrest in G2/M phase. Thus, our study can be a basis for further research to design safe AgNPs in various consumer products. Additionally, similar research can be conducted for different size and shape of AgNP or nano-silver can be engineered using different approaches.

Keywords: Colon cancer cell line; Mechanism of action; Silver nanoparticle; Thermal co-reduction; Toxicity.