Alleviation of hexavalent chromium induced oxidative stress in Drosophila melanogaster using leaf extracts of Moringa oleifera and Bacopa monnieri

Aim: The present study assessed the potential of Moringa oleifera and Bacopa monnieri leaf extracts in amelioration of Cr (VI) induced oxidative stress in Drosophila melanogaster. Methodology: The 96 hr lethal dose (LD50) of chromium was determined by exposing flies to varied doses (10, 20, 30,40,50,60 mg kg-1) of Cr (VI) through diet. Later, flies were exposed to 0, 30 and 50 mg kg-1 of Cr and treated with leaf extracts to evaluate their alleviating effect on lipid peroxidation, catalase and glutathione-S-transferase. In silico studies analyzed the binding pattern of potential bioactive compounds in leaf extracts to the proposed target proteins. Results: LD50 was 50 mg kg-1 obtained through. The lipid peroxidation increased 2 folds with increase in Cr (VI), however, on treatment concentration with leaf extracts it decreased 1.5 times. While glutathione-s-transferase activity was reduced by 50% in Cr (VI) treated flies, the activity significantly increased by 66% and 76% after treatment with Bacopa and Moringa leaf extracts. Catalase activity showed 50% decrease in the flies treated with Cr (VI), while combined treatment of Cr (VI) and leaf extracts showed a significant increase (1.5 times) in catalase activity suggesting recovery. Molecular docking studies on the active phytochemicals of leaf extracts demonstrated their antioxidant potential on par with taurine (ligand), a known antioxidant. Interpretation: The leaf extracts significantly alleviated the Cr (VI) induced oxidative stress, promising a natural therapy to overcome the harmful effects of Cr (VI) exposure in life forms. Key words: Bacopa monneiri, Chromium toxicity, Drosophila melanogaster, Moringa oleifera, Oxidative stress