温肾醒脑方对血管性痴呆大鼠认知功能的影响及机制研究

Effect of Wenshen Xingnao Decoction on Cognitive Function in Vascular Dementia Rats and Its Mechanism

目的:研究温肾醒脑方对血管性痴呆(Vascular dementia,VD)大鼠认知功能的改善作用及对Nrf2、Keap1相关信号通路的影响。方法:70只雄性SD大鼠随机分成正常组、假手术组、模型组、脑复康组(0.15 g/kg)、温肾醒脑方给药组(高剂量组5 g/kg、中剂量组2.5 g/kg、低剂量组1.25 g/kg),每组10只动物。采用双侧颈总动脉永久性结扎法建立VD模型。给予温肾醒脑方灌胃治疗后,Morris水迷宫测试治疗后VD大鼠认知功能的改善情况。检测脑组织中SOD、MDA、GSH-Px、NOS,HE染色观察脑海马组织的病理变化情况,RT-PCR大鼠脑组织NQO1、HO-1的mRNA水平和Western Blot检测Keap1、Nrf2、NQO1、HO-1蛋白水平的表达情况以及EMSA检测Nrf2与ARE结合力。结果:与正常组比较,VD模型组大鼠逃避潜伏期明显较长,游泳总距离明显缩短,穿越站台总数明显减少(P<0.01);大脑组织中MDA含量显著增加,SOD、GSH-Px和NOS的含量明显减少(P<0.01);大脑组织结构明显受损伤,细胞形态改变,细胞核固缩,核仁不清晰;同时大脑组织中细胞核Nrf2蛋白表达降低、细胞质中Keap1蛋白表达增加,NQO1、HO-1 mRNA和蛋白表达降低(P<0.01)。与VD模型组比较,脑复康和温肾醒脑方组大鼠的认知行为得到很大的提高,脑组织MDA、SOD、GSH-Px、NOS含量和脑组织病理结构得到很好的改善,Nrf2、Keap1、NQO1、HO-1在mRNA水平或蛋白水平上有一定程度改变,特别是温肾醒脑方组大鼠的改善非常显著。结论:温肾醒脑方可以改善VD大鼠的认知行为,其机制可能与Nrf2-Keap1-NQO1/HO-1抗氧化应激信号通路相关。

Objective:To study the effect of Wenshen Xingnao Decoction on cognitive function and Nrf2,Keap1 signaling pathway in vascular dementia(VD)rats.Methods:Seventy male SD rats were randomly divided into normal group,sham operation group,model group,Naofukang group(0.15 g/kg),Wenshen Xingnao Decoction group(5 g/kg in high dose group,2.5 g/kg in middle dose group,1.25 g/kg in low dose group),10 rats in each group.VD model was established by bilateral common carotid artery ligation.The cognitive function of VD rats was improved by Morris water maze test after intragastric administration of Wenshen Xingnao Decoction.SOD,MDA,GSH-Px and NOS in brain tissues were detected,and the pathological changes of hippocampus were observed by HE staining.The mRNA levels of NQO1 and HO-1 in brain tissues of RT-PCR rats and the expressions of Keap1,Nrf2,NQO1 and HO-1 proteins were detected by Western blot,and the binding of Nrf2 and ARE was detected by EMSA.Results:Compared with the normal group,the escape latency of VD model rats was significantly longer,the total swimming distance was significantly shortened,and the total number of crossing platforms was significantly reduced(P<0.01).At the same time,the expression of Nrf2 protein in nucleus,Keap1 protein in cytoplasm,NQO1,HO-1 mRNA and protein decreased(P<0.01).Compared with VD model group,the cognitive behavior of Naofukang and Wenshen Xingnao Decoction group was greatly improved,the contents of MDA,SOD,GSH-Px,NOS and the pathological structure of brain tissue were well improved,and the levels of Nrf2,Keap1,NQO1 and HO-1 in mRNA or protein were changed to some extent,especially in Wenshen Xingnao Decoction group.The improvement was very significant.Conclusion:Wenshen Xingnao Decoction can improve cognitive behavior of VD rats,and its mechanism may be related to Nrf2-Keap1-NQO1/HO-1 antioxidant stress signaling pathway.