OBJECTIVE: This study was conducted to investigate the effects of Simvastatin (SIM), a member of statin family, on the cellular antioxidant system, autophagy and apoptosis in NSCs exposed to hydrogen peroxide. BACKGROUND: Reduction in cellular oxidative stress increases the survival of neural stem cells (NSCs) after transplantation into the damaged area of the affected central nervous system. MATERIAL AND METHODS: NSCs derived from bone marrow stromal cells (BMSCs) were exposed to H 2 O 2 (100 μM) for 48 hours after pretreatment with SIM (2 μM). Next, the expressions of the master antioxidant transcription factor, Nrf2/nuclear factor erythroid 2 (NFE2)-related factor 2, autophagy-related proteins (microtubule-associated proteins 1A/1B light chain 3B known as LC3I and LC3II and also p62/ Sequestosome), and apoptosis (Bcl-2/ B-cell lymphoma 2 and Bax/BCL2 associated X protein) were analyzed. RESULTS: SIM caused Nrf2 over-activation (more localizations in the cellular nucleus), reduction in reactive oxygen species (ROS), induction of autophagy (decrease in p62 expression and increase in LC3II/LC3I ratio) and inhibition of apoptosis (decrease in Bax protein and increase in Bcl-2) in NSCs exposed to H 2 O 2-induced oxidative stress, thereby prolonging the cell viability within 48 hours at low concentration (2 μM). CONCLUSION: SIM protects NSCs against H 2 O 2-induced apoptosis in a pleiotropic signaling manner (Fig. 7, Ref. 35).