Inhibition of production of reactive oxygen species and gene expression profile by treatment of ethanol extract of Moutan Cortex Radicis in oxidative stressed PC12 cells.

Moutan Cortex Radicis (MCR) is one of the most widely used Oriental medicines. In this study, we assessed the reducing effect of ethanol extract of MCR on hydrogen peroxide-induced reactive oxygen production, the main cause of cell damage or death in PC12 cells. The viability of cells treated with 1 mg/ml of MCR was significantly restored from that of oxidative-stressed PC12 cells. Measurement of intracellular reactive oxygen species (ROS) generation was determined using the H(2)DCFDA assay. MCR at 1-0.01 mg/ml concentration inhibited ROS production in oxidative-stressed cells. To identify candidate genes responsible for the anti-oxidative effects of MCR on PC12 cells, an oligonucleotide microarray analysis was performed. The result of gene expression profiles showed that 10 genes were up-regulated and 7 were down-regulated in MCR plus hydrogen peroxide treated cells compared with hydrogen peroxide treated cells. Among them, heme oxygenase (HO) and cathechol-O-methyltransferase (COMT) are related to regulation of ROS generation and the others are known to regulate cell survival and progression. Subsequently, we performed real-time RT-PCR to quantify the ROS related gene. MCR treatment increased the expression of HO by 370% and COMT by 280% at the concentration of 1 mg/ml. These findings suggest that MCR inhibits the production of ROS and cytotoxicity by oxidative-stressed PC12 cells through over-expression of HO and COMT.