Background : Rice bran is the outer brown layer of the rice grain and produced when rice is milled. The basic components of rice bran are fiber, lipids, amino acids, vitamins, and minerals. The oil extracted from this bran is called rice bran oil. Although whole rice bran in itself does not have anti-cholesterol properties, its oil offers significant benefits. Ischemic stroke is a major cause of morbidity and mortality worldwide. The cessation or critical reduction of blood flow in brain during acute stroke results in deprivation of the oxygen and glucose supplies, which can produce a local brain ischemia and injury. It is well established that excitotoxicity, a type of neurotoxicity evoked by elevated extracellular glutamate level, is a primary contributor to ischemic neuronal death. The present study aims to investigate the neuroprotective effect of Rice bran oil (RBO) on ischemic brain injury in rats and on excitotoxicity in cultured neurons. Methods and Results : Transient focal ischemic brain damage was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, the infarct and edema volumes of brain tissues were measured using 2,3,5-triphenyltetrazolium chloride (TTC) staining methods. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), inflammatory factors, and anti-apoptotic and pro-apoptotic proteins in brain tissue were detected by Western blot. Primary cortical neuronal cultures were prepared using SD rat fetuses on embryonic days 15. Cortical neurons were treated with N-methyl-D-aspartate (NMDA) (1 mM) for 14 h to produce neuronal cell death. Cell viability was measured by MTT assay. RBO inhibited the formation of infartion and edema in MCAO/reperfusion–induced ischemic brains. The increase of phosphorylated MAPKs, inflammatory factors, and proapoptotic proteins and the decrease of antiapoptotic protein in ischemic brains were significantly inhibited by treatment with RBO. RBO (0.01-1ul/ml) inhibited 1 mM NMDA-induced neuronal cell death in cultured cortical neurons. Conclusion : These results suggest that RBO might be a promising therapeutic for neurodegenerative disease such as stroke.

• Ji Yeon Jang(College of Veterinary Medicine, Chungbuk National University) | 장지연
• Yeon Hee Seong(College of Veterinary Medicine, Chungbuk National University) | 성연희 Corresponding author