Increase of antioxidative potential by tert-butylhydroquinone protects against cell death associated with 6-hydroxydopamine-induced oxidative stress in neuroblastoma SH-SY5Y cells

Abstract

Recent findings suggest that oxidative stress caused by dopamine could be closely involved in the pathogenesis of Parkinson's disease (PD). tert-Butylhydroquinone (tBHQ) is known as a strong inducer of phase II detoxification enzymes which have antioxidative functions. In this study, we investigated the neuroprotective effect of tBHQ against 6-hydroxydopamine (6-OHDA)-induced cell death using human neuroblastoma SH-SY5Y cells. The pretreatment of SH-SY5Y cells with tBHQ significantly reduced 6-OHDA-induced generation of reactive oxygen species (ROS), the phosphorylation of c-Jun N-terminal kinase (JNK), and subsequent cell death. We also observed that tBHQ increased the intracellular glutathione levels and induced the expression of NAD(P)H:quinone oxidoreductase (NQO1) mRNA. In addition, tBHQ dose-dependently activated the antioxidant responsive element (ARE), which plays a key role in the transcriptional activation of phase II detoxification enzymes including NQO1. These results indicate that an increase of intracellular antioxidative potential in SH-SY5Y cells by tBHQ treatment protects cells from 6-OHDA-induced oxidative stress.