基于Nrf2/HO-1信号通路探讨益气活血方对脑缺血损伤大鼠氧化应激反应的影响

目的:以氧化应激损伤为切入点探讨益气活血方对脑缺血损伤大鼠的保护作用。方法:将SD大鼠随机分为模型组,假手术组,尼莫地平组(20 mg·kg~(-1)),益气活血方高、中、低剂量组(2. 916,1. 458,0. 729 g·kg~(-1)),连续灌胃14 d后,采用结扎双侧颈总动脉法建立急性脑缺血损伤模型,透射电镜观察突触超微结构,生化法检测脑匀浆中总超氧化物歧化酶(T-SOD),丙二醛(MDA),乳酸脱氢酶(LDH),谷胱甘肽过氧化物酶(GSH-Px),腺嘌呤核苷三磷酸(ATP)酶的水平,蛋白免疫印迹法(Western blot)和实时荧光定量聚合酶链式反应(Real-time PCR)测定大鼠缺血区脑皮层血红素氧化酶-1(HO-1),核因子E2相关因子2(Nrf2)蛋白和m RNA表达。结果:透射电镜观察结果显示益气活血方对脑缺血损伤程度有明显改善作用。与假手术组比较,模型组大鼠脑匀浆MDA水平显著上升,T-SOD,GSH-Px水平显著降低(P 0. 01),LDH,Na+-K~+-ATP酶,Ca~(2+)-Mg~(2+)-ATP酶及ATP酶的活性均明显降低(P 0. 05,P 0. 01),脑组织中HO-1,Nrf2蛋白含量以及HO-1,Nrf2 m RNA表达显著降低(P 0. 01)。与模型组比较,益气活血方中、高剂量组可明显降低脑组织中MDA含量,升高T-SOD,GSH-Px的水平(P 0. 05,P 0. 01);益气活血方高剂量组可显著增加LDH,Na+-K+-ATP酶,Ca~(2+)-Mg~(2+)-ATP酶和总ATP酶活性(P 0. 05,P 0. 01),益气活血方中、高剂量组大鼠脑组织中HO-1,Nrf2蛋白含量明显升高(P 0. 05,P 0. 01),益气活血方高剂量组HO-1,Nrf2 m RNA表达明显升高(P 0. 05,P 0. 01)。结论:益气活血方可能通过Nrf2/HO-1信号通路抑制氧化应激水平实现对脑缺血损伤的保护作用。

Effect of Yiqi Huoxue Recipe on Oxidative Stress Response in Rats with Cerebral Ischemia Injury Based on Nrf2/HO-1 Signaling Pathway

Objective:To investigate the protective effect of Yiqi Huoxue recipe on rats with cerebral ischemia injury by using oxidative stress injury as an entry point. Method:SD rats were randomly divided into model group, sham operation group, nimodipine group (20 mg·kg^-1), Yiqi Huoxue recipe high, medium and low dose group (2.916,1.458,0.729 g·kg^-1). After 14 days of stomach, acute cerebral ischemic injury model was established by ligation of bilateral common carotid arteries. Ultrasound of synapse was observed by transmission electron microscopy. Total superoxide dismutase (T-SOD) and dialdehyde (MDA), lactate dehydrogenase (LDH), glutathione peroxidase (GSH-Px), horizontal adenine nucleoside triphosphate (ATP) levels were detected by biochemical method. Western blot and Real-time PCR was used to determine the expression of heme oxygenase-1(HO-1) and nuclear factor E₂-related factor 2 (Nrf2) protein and mRNA in the ischemic cortex of rats. Result:Transmission electron microscopy showed that Yiqi Huoxue recipe had a significant improvement on the degree of cerebral ischemic injury. Compared with sham operation group, MDA levels in the brain homogenate of model group increased significantly, T-SOD and GSH-Px levels were significantly decreased (P<0.01). The activity of LDH, Na⁺-K⁺-ATP ase, Ca²⁺-Mg²⁺-ATP ase and ATP was significantly decreased (P<0.05,P<0.01). The levels of HO-1 and Nrf2 protein and the expression of HO-1 and Nrf2 mRNA in brain tissue were significantly decreased (P<0.01). Compared with model group, the medium and high dose group of Yiqi Huoxue recipe significantly decreased MDA content in brain tissue and increased the levels of T-SOD and GSH-Px(P<0.05,P<0.01). Yiqi Huoxue recipe high dose group can significantly increase LDH, Na⁺-K⁺-ATP ase, Ca²⁺-Mg²⁺-ATP ase and total ATP activity(P<0.05,P<0.01). The contents of HO-1 and Nrf2 protein in the brain of rats with middle and high-dose Yiqihuoxue recipe group were significantly increased(P<0.05,P<0.01). The expressions of HO-1 and Nrf2 mRNA in high-dose Yiqi Huoxue recipe group were significantly increased(P<0.05,P<0.01). Conclusion:Yiqi Huoxue recipe may protect against cerebral ischemic injury by inhibiting oxidative stress through Nrf2/HO-1 signaling pathway.