Puerarin protects PC12 cells against β-amyloid-induced cell injury

beta-Amyloid protein (A beta), a major protein component of brain senile plaques in Alzheimer's disease, is known to be directly responsible for the production of reactive oxygen species (ROS) and induction of apoptosis. In this study, the protective effect of puerarin, an isoflavone purified from the radix of the Chinese herb Pueraria lobata, on A beta-induced rat pheochromocytoma (PC12) cultures was investigated. Although exposure of PC12 cells to 50 mu M A beta(25-35) caused significant viability loss and apoptotic rate increase, pretreatment of the cells with puerarin for 24 h reduced the viability loss and apoptotic rate. Puerarin (1 mu M) significantly inhibited A beta(25-35)-induced apoptosis of PC12 cells. Preincubation of the cell with puerarin also restored the ROS and mitochondrial membrane potential levels that had been altered as a result of A beta(25-35) treatment. Puerarin was also found to increase the Bcl-2/Bax ratio and reduce caspase-3 activation. These results suggest that puerarin could attenuate A beta(25-35)-induced PC12 cell injure and apoptosis and could also promote the survival of PC12 cells. Therefore, puerarin may act as an intracellular ROS scavenger, and its antioxidant properties may protect against A beta(25-35)-induced cell injury. (c) 2008 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.