Green synthesized silver nanoparticles: Catalytic dye degradation, in vitro anticancer activity and in vivo toxicity in rats

In this study, silver nanoparticles were synthesized (AgNPs) using aqueous rhizome extract of Acorus calamus (ACRE) and evaluated their in vitro anticancer activity and in vivo toxicity in a Wistar rat model. The synthesized AgNPs showed good catalytic activity against different organic pollutant dyes. In vitro cytotoxic effects of AgNPs were assessed in Hep2, COLO 205 and SH-SY5Y cells using MTT assay. Further, the apoptotic changes induced by AgNPs in more susceptible Hep2 cells were observed through AO/EB, DCFH-DA, Rhodamine 123, PI/DAPI staining, oxidative stress markers and Western blotting. In vivo toxicity study revealed substantial alterations in the levels of serum biochemical markers including AST, ALT, LDH and inflammatory markers such as TNF-α and IL-6 on day 29 when rats treated with AgNPs as compared to control, however, these levels were restored to normal at the end of washout period on day 89. No remarkable changes were observed in liver oxidative stress enzymes. ICP-OES analysis indicated bio-distribution of silver in spleen (5.67 μg/g) and liver (4.98 μg/g) in rats treated with 10 mg/kg b.w of AgNPs on day 29 and elimination of silver from all organs was observed at the end of washout period on day 89. Histopathological analysis revealed no significant changes in kidney, spleen, lungs, heart, testis and brain with 5 and 10 mg/kg b.w of AgNP. However, 10 mg/kg b.w of AgNPs showed moderate degree of cell swelling and vacuolar degeneration in liver and these alterations were reverted back to normal at the end of washout period. Findings from this study signify green synthesized AgNPs at low concentrations might be useful in many ways with ecofriendly nature.