表没食子儿茶素没食子酸酯对大鼠高脂性脂肪肝的治疗作用研究

目的研究表没食子儿茶素没食子酸酯(EGCG)对大鼠高脂性脂肪肝的治疗作用。方法以脂肪乳剂灌胃的方法建立高脂性脂肪肝大鼠模型,造模成功后将高脂性脂肪肝大鼠随机分为EGCG(10、20和40 mg.kg-1)3个剂量治疗组、非诺贝特治疗组(20 mg.kg-1)以及模型对照组。分别观察EGCG对高脂性脂肪肝大鼠的肝重和肝脏系数、血脂水平、肝功能指标以及抗氧化能力的影响;光镜和电镜观察大鼠肝组织脂质变性程度和超微结构的改变。结果EGCG10、20、40 mg.kg-1治疗6 wk后,高脂性脂肪肝大鼠肝重和肝脏系数、血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白-胆固醇(LDL-C)、游离脂肪酸(FFA)、谷丙转氨酶(ALT)和谷草转氨酶(AST)水平以及肝组织中TC和TG含量明显降低(P<0.05或P<0.01),血清高密度脂蛋白-胆固醇(HDL-C)水平明显升高(P<0.05),肝组织中超氧化物歧化酶(SOD)的活性明显升高(P<0.05或P<0.01),同时肝组织中丙二醛(MDA)水平明显降低(P<0.05或P<0.01),并且具有一定的剂量依赖趋势。光镜和电镜观察结果表明,给予EGCG的大鼠肝组织脂质变性程度和肝细胞超微结构改变明显减轻(P<0.01)。结论EGCG 10、20、40mg.kg-1治疗6 wk后,对高脂性脂肪肝大鼠具有较好的治疗作用,其作用机制可能与降低血脂水平和增强机体的抗氧化能力有关。

Therapeutic effect of epigallocatechin gallate on hyperlipidemic fatty liver in rats

Aim To investigate whether epigallocatechin gallate(EGCG) had therapeutic effect on hyperlipidemic fatty liver and its possible mechanism in rats.Methods Rat model with hyperlipidemic fatty liver was successfully established by feeding fatty milk for 6 weeks.The experimental rats were then treated with EGCG 10~40 mg·kg-1 for 6 weeks.The therapeutic and antioxidation effects of EGCG on hyperlipidemic fatty liver were observed.Histopathological changes of rat liver were observed under light and electron microscopy.Results After treatment with EGCG,the rat serum levels of total cholesterol(TC),triglyceride(TG),low density lipoprotein-cholesterol(LDL-C),free fatty acids(FFA),alanine transaminase(ALT) and aspartate transaminase(AST) were significantly decreased as compared with the fatty liver model group.The hepatic weight and its coefficient,the hepatic tissue contents of TC,TG,and malondialdehyde(MDA) in EGCG-treated groups were also significantly decreased,while the serum high density lipoprotein-cholesterol(HDL-C) and hepatic tissue contents of superoxide dismutase(SOD) were obviously increased.Importantly,the histological evaluation of rat liver demonstrated that EGCG dramatically decreased lipid accumulation.Conclusion EGCG possesses the therapeutic effect on fatty milk-induced rat fatty liver,and the mechanism may be associated with its antioxidation.