Oxidative stress plays an important role in many
neurodegenerative disorders. In this study, the effect of
baicalein, a natural
flavonoid isolated from the root of Scutellaria baicalensis G., on
hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells were investigated. Exposure of PC12 cells to 0.15 mM H2O2 for 20 min induced a significant decrease in cell viability accompanied by increased oxidative stress,
mitochondrial dysfunction, downregulation of Bcl-2, upregulation of Bax, and cell apoptosis. Pretreatment of PC12 cells with
baicalein inhibited H2O2-induced cell viability loss, intracellular
reactive oxygen species generation, and lipid peroxidation in a dose-dependent manner. Meanwhile,
baicalein potentially inhibited H2O2-induced cell apoptosis characterized with the
DNA fragment. And the mitochondrial pathway involving the
mitochondrial dysfunction associated with cell apoptosis including membrane potential loss, the release of
cytochrome c, the downregulation of Bcl-2, upregulation of Bax induced by H2O2 were also abrogated in the presence of
baicalein. Taken together, these results suggest that
baicalein can block H2O2-induced apoptosis by prevention of oxidative stress as well as regulation of Bcl-2 family members and suppression of
mitochondria dysfunction, which might be beneficial for the treatment of oxidative stress in aging and age-associated
neurodegenerative diseases.