α-Tocopherol Prevents ERK1/2 Activation in PC12 Cells under Conditions of Oxidative Stress and Its Contribution to the Protective Effect

Preincubation with 100 nM and 100 μM α-tocopherol for 18 h prevented long-term activation of extracellular signal-activated kinase (ERK1/2), induced by H2O2 in PC12 cells. α-Tocopherol significantly reduced H2O2-induced death of PC12 cell, but its protective effect was signifi cantly lower in the presence of ERK1/2 inhibitor. These data show that prevention of long-term activation of ERK1/2 by α-tocopherol contributes to the increase in viability of PC12 cells exposed to H2O2. This fact suggests that inhibition of ERK1/2 activity by α-tocopherol reduces neuronal cell death in the brain under conditions of oxidative stress in vivo.