Neuroprotective effect of α-tocopherolhydroquinone against glutamate-induced cytotoxicity in N18-RE-105 cells

Oxidative stress is the imbalance between the production rate of oxidant and the level of antioxidants, and is associated with neurodegenerative disease. The aim of this study was to better understand the cellular mechanisms of neuronal cell degeneration induced by oxidative stress and the protective roles of bioactive substances. Therefore, we established a screening program to identify therapeutic agents that exhibit a preferential neuroprotective activity in glutamate-treated N18-RE- 105 cells. During the course of our screening program, we isolated an active compound, a-tocopherolhydroquinone (TQH2), from persimmon peel. The protective effect of TQH2 against glutamate-induced oxidative damage in cells was investigated using the MTT and LDH assay. Interestingly, flow cytometric analysis showed that TQH2 pretreatment greatly reduced apoptosis. TQH2 pretreatment was also associated with reduced levels of phosphor-p38, PARP, and cleaved caspase-3. The results of this study suggest that TQH2 is a novel antioxidant with a potential to protect against neuronal diseases.