牛蒡子苷元对四氯化碳致大鼠肝纤维化的治疗作用

摘要

目的：研究牛蒡子苷元（ATG）对四氯化碳（CCl4）诱导的大鼠肝纤维化的防治作用及可能的作用机制。方法成年Sprague-Dawley大鼠随机分为溶剂对照组、ATG 3.0 mg·kg-1、CCl4模型组、CCl4+ATG 1.0和3.0 mg·kg-1组和CCl4+秋水仙碱（COL）0.1 mg·kg-1阳性对照组，采用sc的方法复制大鼠CCl4肝纤维化模型，造模8周。从第5周开始，ig给予ATG和COL，连续治疗4周。测定各组大鼠血清中谷丙转氨酶（GPT）、谷草转氨酶（GOT）的活性以及白蛋白（ALB）、总胆红素（TBIL）的水平，肝组织中羟脯氨酸（HYP）的含量；HE和Masson染色观察肝组织病理改变，并采用组织免疫荧光法检测活化的肝星状细胞增殖，Western蛋白质印迹法检测细胞周期相关蛋白的表达。结果与CCl4模型组比较，ATG 1.0和3.0 mg·kg-1可显著升高纤维化大鼠血清中ALB含量（P<0.05），降低血清中GPT，AST和TBIL水平（P<0.05），从而降低肝损伤的程度；ATG 1.0和3.0 mg·kg-1还能显著降低纤维化大鼠肝组织中HYP的含量（P<0.05），减少肝内纤维组织的形成。同时，ATG 1.0和3.0 mg·kg-1还能抑制纤维化大鼠肝组织中活化的HSC增殖，显著降低细胞周期相关调控蛋白细胞周期蛋白D1（cyclin D1）、细胞周期蛋白依赖性蛋白激酶（CDK）2和4及增殖细胞核抗原的表达（P<0.05），同时上调细胞周期阻抑物蛋白p27kip1的表达水平（P<0.05）。结论 ATG对CCl4诱导的大鼠肝损伤和肝纤维化具有显著的治疗作用，其作用机制可能与抑制活化的HSC增殖相关。%OBJECTIVE To investigate the effect of arctigenin(ATG) on liver fibrosis in rats induced by carbon tetrachloride(CCl4)and to explore its underlying mechanism. METHODS Sprague-Dawley rats were randomly divided into six groups:vehicle,ATG 3.0 mg · kg-1 group,CCl4 model group,CCl4+ATG 1.0 and 3.0 mg·kg-1 groups,and CCl4+colchicine(COL)0.1 mg·kg-1(toxicity)group. Liver fibrosis was induced by subcutaneous injection of CCl4 in rats for 8 weeks. ATG and colchicine were administrated ig once a day starting from the fifth week after the CCl4 treatment for 4 weeks subsequent. At the end of the study,glutamic pyruvic transaminase (GPT),glutamic oxaloacetic transaminase(GOT),albumin(ALB),and total bilirubin (TBIL) as well as the contents of hydroxyproline (HYP) in liver tissues were measured. Histopathological changes were observed in the liver tissues using hematoxyline-eosin(HE)and Masson’s trichrome staining. The proliferation of hepatic stellate cells (HSC) and expression of cell cycle-related proteins were assayed by indirect immunofluores⁃cence staining and Western blotting,respectively. RESULTS Compared with CCl4 model group,ATG 1.0 and 3.0 mg · kg-1 improved the liver function by decreasing serum contents of GPT,GOT and TBIL (P<0.05),and increasing serum content of albumin(P<0.05). Histological results indicated that ATG 1.0 and 3.0 mg · kg-1 alleviated liver damage and reduced the formation of fibrous septa. Moreover, ATG 1.0 and 3.0 mg · kg-1 significantly decreased liver HYP when compared with CCl4 model group(P<0.05). In addition,CCl4-induced proliferation of activated HSC was inhibited by ATG 1.0 and 3.0 mg·kg-1, and this was accompanied by down-regulation of cyclin D1,cyclin-dependent kinase(CDK)2,CDK4, and proliferating cell nuclear antigen (PCNA)(P<0.05),and up-regulation of p27kip1 in activated HSC (P<0.05). CONCLUSION ATG can alleviate hepatic injury and fibrosis induced by CCl4,which is probably associated with suppression of the proliferation of activated HSC.