Withania somnifera promotes stress resistant activity in Drosophila melanogaster

Stress is a state of mental or emotional strain of an individual.  In recent years nutritional antioxidants study have gain more attention in minimizing the stress like oxidative stress. The stress resistant ability in an organism can be increased by the supplementation of herbal resources. However, few plant extracts are known to have stress resistant ability and increases the tolerance capacity. Plants containing high antioxidant and other bioactive compounds promote tolerance capacity. An antioxidant rich plant has been proved to decreases the   lipid peroxidation. Here, we investigated the potential protective effect of ethanolic extract of Withania somnifera (WS), against Paraquat toxicity on stress tolerance capacity using Drosophila melanogaster. Wild-type fruit flies of Oregon-K strain were fed with standard food media with 1mg/ml and 10 mg/ml of WS.  The oxidative stress was induced by exposing the extract supplemented flies to Paraquat (20 mM).  The stress tolerance capacity of flies was measured by subjecting to desiccation and oxidative stresses. Further, locomotor activity, lipid peroxidation were also studied along with the quantification of triglycerides, glycogen in WS fed flies under stress conditions. Our result reveals that PQ induced WS fed flies showed greater survivability, better locomotor ability when compared to PQ induced flies.WS fed flies increases about 73.55% of resistance ability under oxidative conditions and increased by 59.15% under desiccation than PQ induced flies. WS was more effective in protecting against Paraquat toxicity. The flies fed with high dose of WS (10mg/ml) showed greater improvement of the tolerance ability when subjected to desiccation and oxidative stresses. Further, the data on biochemical analysis reveals that lipid peroxidation activities were found to be significantly low and the triglyceride as well as glycogen quantities were found to be significantly high in WS fed flies compare to –ve control under both desiccation and oxidative stress conditions.  Together, these findings suggest that WS promotes stress resistant ability by modulating metabolism and reducing oxidative damage. Keywords: Drosophila melanogaster, Withania somnifera, Oxidative stress assay, Desiccation Assay, Negative Geotaxis,