Protective effects of flavonoids from the leaves of Carya cathayensis Sarg. against H(2)O(2)-induced oxidative damage and apoptosis in vitro

Hydrogen peroxide (H(2)O(2)) can induce apoptosis by releasing reactive oxygen species (ROS) and reactive nitrogen species, which cause mitochondrial damage. The present study aimed to investigate the protective effects of flavonoids from the leaves of Carya cathayensis Sarg. against H(2)O(2)-induced oxidative damage and apoptosis in vitro. The bioactivity of total flavonoids (TFs) and five monomeric flavonoids [cardamonin (Car), pinostrobin chalcone, wogonin, chrysin and pinocembrin] from the leaves of Carya cathayensis Sarg. (LCCS) were tested to prevent oxidative damage to rat aortic endothelial cells (RAECs) induced by H(2)O(2). Oxidated superoxide dismutase, glutathione peroxidase, malondialdehyde, lactate dehydrogenase and ROS were analyzed to evaluate the antioxidant activity. Gene and protein expression patterns were assessed using reverse transcription-quantitative PCR and western blotting, respectively. The results indicated that TFs and Car inhibited H(2)O(2)-induced cytotoxicity and apoptosis of RAECs. Additionally, they regulated the level of oxidase and inhibited the production of ROS. Overall, the TFs extracted from LCCS could potentially be developed as effective candidate drugs to prevent oxidative stress in the future; moreover, they could also provide a direction in investigations for preventing antioxidant activity through the ROS pathway.