Modulatory Effect of Decalepis hamiltonii on Ethanol-Induced Neurotoxicity in Drosophila melanogaster

Ethanol is known to be an effective inducer of oxidative stress in the brain tissues. Drosophila melanogaster is suitable in vivo model system to study neurotoxic effects of ethanol. The behavioral responses, levels of oxidative markers, and activity of antioxidant enzymes have been investigated in ethanol-exposed Drosophila flies. The results showed that acute ethanol exposure leads to hyperactivity of flies. If alcohol exposure is prolonged then sedation has occurred in the experimental flies. The latter was measured by sensitivity time (ST50) and recovery time (RC50). The levels of ROS and LPO (as cellular markers of oxidative stress) are significantly increased in ethanol-exposed flies while GSH level was declined. Furthermore, higher activities of catalase (CAT) and superoxide dismutase (SOD) were observed in the same group of flies. Ethanol neurotoxicity became more evident when a remarkable decrease of acetylcholine esterase (AChE) activity was seen in ethanol-exposed fruit flies. To battle ethanol neurotoxicity natural antioxidants would be the best choice. According to previously reported studies on the antioxidant capacity of Decalepis hamiltonii (Dh) root extract, its protecting effect in this toxicity model has been investigated. Surprisingly, Dh aqueous extract treatment has increased the time of ST50 and decreased the RC50 values of ethanol-exposed flies. Moreover, we demonstrated that Dh pre-treatment can diminish the ROS and LPO levels. Dh treatment results in augment of GSH level and activity of CAT and SOD enzymes. Antioxidant potential of Dh could restore AChE activity too. This is the first report on protective effects of Dh natural antioxidants in Drosophila melanogaster against oxidative stress induced by ethanol.