Neuroprotective Effects of Deuterium-Depleted Water (DDW) Against H₂O₂-Induced Oxidative Stress in Differentiated...

Oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Induction of endogenous antioxidants to act against oxidative stress-mediated neuronal damage seems to be a reasonable strategy for delaying the progression of such diseases. In this study, we investigated the neuroprotective effect of deuterium-depleted water (DDW) against H₂O₂-induced oxidative stress in differentiated PC12 cells and the possible signaling pathways involved. The differentiated PC12 cell line was pretreated with DDW containing different concentrations (50-100 ppm) of deuterium and then treated with H₂O₂ to induce oxidative stress and neurotoxicity. We assessed cell survival, reactive oxygen species (ROS) generation, TUNEL assay, catalase (CAT), copper and zinc-containing superoxide dismutase (CuZn-SOD) and superoxide dismutase (SOD) activity and performed Western blot analysis to investigate the neuroprotective effect of DDW. The results indicated that DDW could attenuate H₂O₂-induced apoptosis, reduce ROS formation, and increase CAT, CuZn-SOD and SOD activity in H₂O₂-treated PC12 cells. Western blot analysis revealed that DDW treatment significantly increased the expression of p-Akt, Bcl-2 and GSK-3β. However, the protective effect of DDW on cell survival and the DDW-mediated increases in p-Akt, Bcl-2 and GSK-3β were abolished by pretreatment with the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002. In summary, DDW may protect differentiated PC12 cells against H₂O₂-induced oxidative stress through the PI3K/Akt signaling pathway.