氧化苦参碱通过激活Nrf2/HO-1通路减轻肝硬化大鼠肠道氧化应激损伤

Study of oxymatrine in reducing intestinal oxidative stress injury by activating Nrf2/HO-1 pathway in cirrhosis rats

目的:探讨苦参碱(Oxymatrine,OMT)对肝硬化肠道屏障功能的影响及其可能的机制。方法:SD大鼠随机分为3组:正常大鼠为空白对照组(Control组)、具有肠屏障破坏的肝硬化模型组(Model组)和氧化苦参碱治疗肝硬化大鼠实验组(OMT组)。实验组SD大鼠肌肉注射OMT(6.3 mg·100 g^(-1),1次·d^(-1))4周,模型组使用同等剂量的生理盐水代替。实验中记录大鼠体重变化,并选择回肠末端进行HE染色。并测定肠道抗氧化酶含量,包括超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)、总抗氧化能力(T-AOC)和丙二醛(MDA)。Western blot法检测回肠末端核转录因子红系2相关因子2(Nuclear factor-erythroid 2-related factor 2,Nrf2)和血红素加氧酶-1(Heme oxygenase-1,HO-1)的表达。结果:与模型组SD大鼠相比,实验组大鼠体重增加更多(P<0.05),HE观察到实验组肠道隐窝萎缩减轻,黏膜破坏和炎症浸润减轻。肠道SOD、CAT、GSH、T-AOC、HO-1升高,MDA浓度降低(P<0.05)。此外,Western blot显示实验组肠道组织细胞核内p-Nrf2和Nrf2的表达均增加(P<0.05),细胞质p-Nrf2表达显著增加(P<0.05),Nrf2表达无明显改变。细胞质及细胞核p-Nrf2/Nrf2比值均升高。结论:OMT能够减轻肝硬化大鼠肠道氧化应激损伤,维持肠上皮通路屏障的完整性,其机制可能为通过参与Nrf2/HO-1通路的活化。

Objective:To investigate the effect of OMT on intestinal epithelial barrier function and the underlying mechanism in cirrhotic intestinal barrier.Methods:The rats were randomly divided into three groups:normal rats as blank control group(control group),Model group of cirrhosis with intestinal barrier failure(Model group),and experimental group of rats treated with oxymatrine(OMT group).Rats in the experimental group received intramuscular injection of OMT(6.3 mg·100 g^(-1))for 4 weeks,and the model group received the same dose of normal saline instead.The body weight changes were recorded.Terminal ileum was selection for hematoxylin&eosin staining.The anti-oxidative enzyme,including SOD,CAT,GSH,T-AOC,and MDA were determined.Nrf2,HO-1 were also determined by western blot in terminal ileum.Results:Compared to control group SD rats,body weight in the experimental group increased significantly(P<0.05).H&E pathological examination showed that the degeneration of intestinal crypts,mucosal ulcer and infiltration of inflammatory were relieved.The anti-oxidative enzyme expression in terminal ileum as follows:the expression of SOD,CAT,GSH,HO-1 was elevated(P<0.05).T-AOC raised significantly(P<0.05).However,the MDA concentrates significantly decreased in the experimental group(P<0.05).Western bolt showed that the expression of p-Nrf2 was significantly increased(P<0.05)in the cytoplasm.The expression of p-Nrf2 and Nrf2 were significantly increased in nuclear(P<0.05).There was no significant change in Nrf2 expression.The expression of HO-1 increased in Terminal ileum(P<0.05).Conclusion:OMT maintain Intestinal Epithelial Barrier integrity by remission oxidative stress injuries in cirrhosis rats.The protective effect of OMT on intestinal barrier may activate Nrf2/HO-1 signal pathway and increase the expression of claudin-4.