Effects of notoginsenoside-Rg1 on the expression of apoptosis factors in brain tissue after ischemia injury

ZHAN He-qin; ZHANG Wen-xi; YAN Fu-lin; LIU Feng-qi; ZHANG Xiao-yi; HAI Guang-fan; LIU Wei; AI Fang; SHAO Huan-xia; SHAO Li-wei

Abstract：Objective To investigate the effects of notoginsenoside-Rg1 on Bcl-2 and Bax protein expression in cerebral cortex , cerebellum and bulbus medullae .Methods Male SD rats were randomly divided into six groups , inclu-ding sham group (Group S), model group (Group M), model+positive control group (Group N), and model+notogin-senoside-Rg1 25, 50 and 100 mg/kg groups (Group RL, Group RM and Group RH).The Middle cerebral artery occlu-sion-reperfusion model was induced by clue -blocked method ( blocking arterial flow for 2 hours, reperfusion for 24 hours).The drugs were administered intraperitoneally twice a day .The rats in Group S and M were given with normal sa-line;the rats in Group N were given with nimodipine (1 mg/kg); while the rats in Group RL, RM and RH were given with notoginsenoside-Rg1 of 25, 50, and 100 mg/kg, respectively.The neurological deficit scores and animal mortality were evaluated 24 hours after drug administration .The immunohistochemistry were used to detect the protein expression of Bcl-2 and Bax in cerebral cortex , cerebellum and medulla oblongata .Results Rats administered with notoginsenoside-Rg1 showed a significant decrease in neurological deficit scores and animal mortality than the Group M , and increased ratio of Bcl-2 and Bax protein in cerebral cortex , cerebellum and medulla oblongata (P<0.05, P<0.01).The Group RM was remarkably different compared with Group RL except the ratio of Bcl -2/Bax protein in cerebral cortex (P<0.05), and there was dose-response relationship between them .In the neurologic deficit symptom scores and animals mortality , The Group RM and Group RL were significantly different compared with Group N (P<0.05, P<0.01).In Bcl-2/Bax of cerebral cortex and medulla oblongata , all groups of notoginsenoside -Rg1 were significant different compared with Group N (P<0.05, P<0.01).In Bcl-2/Bax of cerebellar, only Group RM was significantly different compared with Group N (P<0.05).Conclusion The mechanism of notoginsenoside-Rg1 against brain ischemia injury may be related to the up-regulation of Bcl -2 protein of erebral cortex , cerebellum and bulbus medullae , and down-regulation of Bax protein as well as raise of Bcl -2/Bax of the cerebral cortex and bulbus medullae .