D-Ribose-L-Cysteine and L-Dopa Co-Supplementation Attenuates Paraquat-Induced Oxidative Damage and Locomotion Deficit in Drosophila melanogaster

Abstract

D-ribose L-cysteine is a glutathione precursor that acts as an antioxidant. In the present study, we investigated the effect of D-ribose L-cysteine and L-dopa combination against paraquat toxicity in Drosophila melanogaster. Adult wild-type flies were exposed to Paraquat (500 μM), RLC (250 μM), and/or L-dopa (0.1 mM) in their diet for 7 days. The survival rate, locomotion activities, and markers of antioxidants (Catalase, glutathione-S-transferase, superoxide dismutase, thioredoxin reductase, total and non-protein thiol), oxidative stress (hydrogen peroxide, protein carbonyl, malondialdehyde, nitrite/nitrates), and dehydrogenase activity were measured in the flies. The results showed a non-toxic effect of the combination of RLC and L-dopa. In addition, elevated oxidative stress markers due to paraquat treatments were significantly reduced after treatments with RLC and L-dopa. Combination treatment also significantly restored altered antioxidant status, improved survival rate, and impaired locomotion induced by paraquat. This study suggests that RLC could serve as adjunct therapy with L-dopa in managing Parkinson’s disease and toxicity associated with paraquat and related compounds