Management of stress exerted by hydrogen peroxide in Drosophila melanogaster using Abhrak bhasma

Abstract

One of the undesirable outcomes of aerobic respiration is development of reactive oxygen species (ROS) and other free radicals. The cellular antioxidant system continuously reduces these into less toxic molecules. A common end product of quenching of ROS is hydrogen peroxide (H2O2), though this too is an oxidant and is further converted into water and molecular oxygen by antioxidant enzymes. We monitored selected indicators of oxidative stress after exposing Drosophila larvae to sub lethal concentration of H2O2. The efficacy of dietary supplementation of abhrak bhasma and ascorbic acid in relieving the oxidative stress, induced by H2O2, was also evaluated in this study. The exposure of Drosophila larvae to H2O2 was found to modulate the activity of SOD and catalase enzymes. The larvae exposed to H2O2 but maintained on a medium free of antioxidant supplement (control) exhibited decrease in total GSH content, GSH:GSSG ratio and capacity to scavenge DPPH free radicals. Overall, supplementing the diet with abhrak bhasma seems to enhance the antioxidant machinery of the Drosophila larvae. The comparable results were also obtained for the larvae maintained in a medium supplemented with a known antioxidant, ascorbic acid.