雷公藤红素对二乙基亚硝胺诱导的大鼠肝纤维化的治疗作用及机制

目的观察雷公藤红素(Celastrol,Cel)对二乙基亚硝胺(DEN)诱导大鼠肝纤维化的治疗作用及机制。方法采用DEN诱导大鼠肝纤维化模型,分为正常对照组、模型组、Cel给药组(2、4、8 mg.kg-1)和秋水仙碱组(Col,0.1 mg.kg-1)。紫外分光光度法检测各组大鼠血清中AST、ALT、肝组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及肝组织中丙二醛(MDA)、羟脯氨酸(HYP)的含量;ELISA检测大鼠血清中透明质酸(HA)、层粘蛋白(LN)、Ⅲ型前胶原(PCIII)、Ⅳ型前胶原(CIV)、TGF-β1的含量;Western blot检测肝脏α-平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原(ColⅠ)和TGF-β1蛋白的表达;HE染色观察肝组织病理形态学变化;Masson染色观察肝组织中胶原沉积变化。结果与模型组比较,Cel能明显降低肝纤维化大鼠血清中升高的TGF-β1、ALT、AST、HA、LN、PCIII含量,降低肝组织中升高的HYP和MDA的含量,明显升高肝组织中SOD和GSH-Px酶活性,减少肝纤维化大鼠肝组织中α-SMA、Col I和TGF-β1的表达,改善其肝脏病理损伤程度,减少肝脏中胶原沉积。结论 Cel对肝纤维化大鼠有很好的治疗作用,其作用机制可能与Cel的抗氧化作用,降低TGF-β1的表达,抑制HSC活化,抑制胶原合成有关。

Therapeutic effects of celastrol on DEN induced liver fibrosis rats and its mechanisms

Aim To investigate the effects of celastrol(Cel) on liver fibrosis in rats induced by diethyl nitrosamines(DEN) and to explore its possible mechanisms.Methods Liver fibrosis was induced in rats by gavage with DEN.The rats were randomly divided into 6 groups,namely normal control group,liver fibrosis model group,Cel(2,4,8 mg·kg-1)treated groups and colchicine(0.1 mg·kg-1) treated group.The activities of ALT,AST,superoxide dismutase(SOD),glutathione peroxidase(GSH-Px) in serum and the levels of malondialdehyde(MDA),hydroxyproline(HYP) in liver tissue were evaluated by spectrophotometry using commercially kits.The levels of hyaluronic acid(HA),laminin(LN),procollagen typeIII(PCIII),typeIV collagen(CIV) and TGF-β1 in serum were determined using rat enzymelinked immunoadsordent assay(ELISA) kit.The protein expressions of α-SMA,Col I and TGF-β1 were measured by Western blot.The samples were stained with HE and Masson for histopathological examination.Results Cel obviously decreased activities of serum AST,ALT,levels of HA,LN and PCIII,and Hyp elevated by DEN,and reduced levels of MDA and TGF-β1 in liver tissue;it also restored activites of SOD and GSH-Px in liver tissue;moreover,Cel could reduce the expression of α-SMA,Col I and TGF-β1 in Western blot assay.Cel significantly reduced the liver damage and the symptoms of liver fibrosis.Conclusions Cel significantly inhibits the progression of hepatic fibrosis induced by DEN,and its inhibitory effect on rat hepatic fibrosis might be associated with its scavenging free radicals,decreasing the level of TGF-β1,and inhibiting collagen synthesis and activation in HSCs.