丹酚酸B对非酒精性脂肪性肝炎大鼠肝细胞凋亡的影响

Effect of salvianolic acid B on hepatocyte apoptosis in rats with nonalcoholic steatohepatitis

目的探讨丹酚酸B对非酒精性脂肪性肝炎(NASH)大鼠肝细胞凋亡的影响及对NASH的治疗作用。方法清洁级雄性SD大鼠60只,随机分为对照组、NASH模型组、丹酚酸B治疗组,每组20只。对照组以普通饲料喂养,其余2组以高脂饲料连续喂养12周复制NASH模型。第13周开始治疗组每天以浓度为1 mg/ml的丹酚酸B溶液20 ml/kg灌胃,模型组以20 ml/kg蒸馏水灌胃。治疗12周后,处死大鼠,取血及肝组织,计算肝指数,检测血清ALT、AST、甘油三酯(TG)、总胆固醇(TC),观察肝组织病理学变化,免疫组织化学法检测肝组织细胞色素C(Cyt C)、caspase-3蛋白的表达,逆转录-聚合酶链反应(RT-PCR)检测肝组织p53、Bax、Bcl-2 mRNA的表达。结果模型组大鼠肝指数、ALT、AST、TG、TC较对照组增高,肝组织炎症明显;Cyt C及caspase-3蛋白表达增加(P值均<0.01);Bcl-2 mRNA表达降低,p53、Bax mRNA表达增高(P值均<0.01)。治疗组与模型组相比肝指数、ALT、AST、TG、TC降低,炎症减轻;Cyt C及caspase-3蛋白表达减少(P值均<0.01);Bcl-2 mRNA表达升高(P<0.05),p53 mRNA表达降低(P<0.05),Bax mRNA表达降低(P<0.01)。结论丹酚酸B可通过调节Bcl-2、p53、Bax mRNA表达,降低Cyt C及caspase-3蛋白的表达,抑制肝细胞凋亡,对NASH起治疗作用。

Objective To investigate the effect of salvianolic acid B on hepatocyte apoptosis in rats with nonalcoholic steatohepatitis （NASH）and the efficacy of salvianolic acid B in the treatment of NASH.Methods Sixty clean male SD rats were randomly divided into control group,NASH model group,and salvianolic acid B treatment group,with 20 rats in each group.The control group was fed with normal diet,while the other two groups with high-fat diet for 12 continuous weeks to establish a NASH model.From week 13,rats in the treatment group were gavaged with 1 mg/ml salvianolic acid B （20 ml/kg b.w.daily）;while the model group with distilled water （20 ml/kg b.w dai-ly）.After 12 weeks of treatment,the rats were sacrificed;blood and hepatic tissues were sampled,liver index （liver weight/body weight） calculated,serum levels of alanine aminotransferase （ALT）,aspartate aminotransferase （AST）,triglycerides （TG）,and total cholesterol （TC）measured,and the pathologic changes in hepatic tissues observed.The protein expression of caspase-3 and cytochrome C （CytC）in hepatic tissues was measured by immunohistochemical methods.The mRNA expression of p53,Bax,and Bcl -2 in hepatic tissues was measured by RT-PCR.Results Compared with the normal group,the model group showed higher liver index and serum levels of ALT, AST,TG,and TC and more obvious inflammation of hepatic tissues;the protein expression of CytC and caspase -3 was significantly in-creased （P＆lt;0.01 for both）;the mRNA expression of Bcl-2 was significantly reduced （P＆lt;0.01）,while that of Bax and p53 was signifi-cantly increased （P＆lt;0.01 for both）.Compared with the model group,the treatment group showed alleviated inflammation and reduced liver index and serum levels of ALT,AST,TG,and TC;the protein expression of CytC and caspase-3 was significantly reduced （P＆lt;0.01 for both）;Bcl-2 mRNA expression was significantly increased （P＆lt;0.05 ）,p53 mRNA expression significantly reduced （P＆lt;0.05 ）,and Bax mRNA expression also significantly reduced （P＆lt;0.01 ）.Conclusion Salvianolic acid B can inhibit hepatocyte apoptosis and treat NASH by regulating the mRNA expression of Bcl-2,p53,and Bax and reducing the protein expression of CytC and caspase-3.