Neuroprotective properties of phytochemicals against paraquat-induced oxidative stress and neurotoxicity in Drosophila melanogaster

Environmental toxicants like paraquat (PQ) induce the increase of oxidative stress, which is likely to lead to various neuropathological symptoms. Although the Drosophila system is applicable for anti-oxidative and neuroprotective drug discovery, this system remains to be more exploited in various aspects. In this study, using Drosophila as a model animal, we have examined the anti-oxidative and neuroprotective properties of plant-derived compounds against oxidative damage and neurotoxicity induced by paraquat, which is a widely used herbicide. In this study, paraquat showed LC50 at 24.7 mM to adult males of Drosophila melanogaster within 24 h. Dietary feeding of curcumin, quercetin, Sanguisorba officinalis, and Zedoariae rhizoma extracts prior to paraquat exposure extended lifespan and enhanced motor activities of flies. These compounds modulated the expression level of several genes associated with anti-oxidative and anti-aging effects such as sod1, sod2, cat, gstD1, and mth genes. Also, same treatments of phytochemicals to flies ameliorated other oxidative stress index factors such as ROS levels and superoxide dismutase. In contrast, no significant effects on catalase activities were observed. Additionally, the dietary feeding of phytochemical substances also reduced acetylcholine esterase activities, which were dramatically increased by paraquat treatment, implying that these phytochemicals also affected neuronal systems. Present study demonstrates that the dietary feeding of phytochemicals prior to paraquat exposure has anti-oxidative and neural protective effects, which leads to the recovery of behaviors and lifespan in fruit flies.

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► Phytochemicals extend lifespan and enhanced motor activities of flies.
► Curcumin, quercetin, and other plant extracts reduce paraquat-induced oxidant stress.
► Tested phytochemicals alter gene expression associated with anti-oxidative stress.