?-oryzanol Prevents L02 Cells Oxidative Damage Induced By Hydrogen Peroxide Via Mitochondrial Signaling Pathway

y-Oryzanol, one of the most important bioactive substance in rice bran oil, shows broad spectrum of biological activities, such as lowering risk of cardiovascular disease, anti-cancer, modulation of autonomic nervous system, antioxidant, hypolipidemic, anti-diabetes, and anti-obesity. ?-Oryzanol has a very promising application in the animal farming and functional food industry. However, there is barely research on mechanisms of y-oryzanol against oxidative stress. In this project, L02 Cells line were used as a research model to investigate the protective effect and molecular mechanism of ?-oryzanol against oxidative damage induced by hydrogen peroxide, using the experimental methodologies of celluar biology biochemistry and pharmacology. It would shed light on the theoretic research and scientific application of oxidative stress.Objective:To investigate the protective effect and molecular mechanism of y-oryzanol on L02 cell against oxidative damage induced by hydrogen peroxide.Methods:The model of oxidative damage was set up on L02 cells induced by H2O2. The cell viability was determined by MTT, the contents of malondialdehyde (MDA) and glutathione (GSH), and the activities of superoxide dismutase (SOD) and catalase (CAT were assayed by adding different concentration of y-oryzanol into L02 cells in vitro. The percentage of cell apoptosis was deteced by flow cytometer, and intracellular reactive oxygen species (ROS) level was assayed by DCFH-DA and mitochondrial membrane potential (?m) in L02 cellswas determined by fluorescent probe JC-1. The genes expressions of Bcl-2, Bax, Caspase-9 and Caspase-3 were determined by RT-PCR, and the protein expressions of Bcl-2, Bax, Caspase-9 and Caspase-3 were determined by western blot.Results:1) The cell viability was enhanced significantly, and the levels of ROS and MDA were significantly decreased, whereas the content of GSH and the activities of CAT and SOD were significantly increased by 0.1-0.4mM y-oryzanol pretreatment after H2O2-induced oxidative damage in a dose dependent manner. ?-Oryzanol can effectively attenuate H2O2-induced oxidative damage at the dose of 0.1-0.4mM and maintain the normal physiology of the cells.2) y-oryzanol pretreatment restored mitochondrial function, decreased the expression of pro-apoptotic protein Bax, prevented the decline of anti-apoptotic protein Bcl-2, inhibited caspase-9 and caspase-3 activation, and improved cell survival in a dose dependent manner.Conclusions:?-oryzanol can effectively attenuate H2O2-induced oxidative damage via mitochondrial mediated signal pathwayand maintain the normal physiology of the cells.