参苓白术散对NAFLD大鼠肝组织Nrf2/ARE信号通路的影响

Effects of Shenling Baizhu Powder on Nrf2/ARE Pathway in Liver Tissue of Nonalcoholic Fatty Liver Disease Rats

目的观察参苓白术散对高脂饮食诱导的非酒精性脂肪性肝病(NAFLD)大鼠肝组织核因子E2相关因子2/抗氧化反应元件(Nrf2/ARE)信号通路相关蛋白表达的影响。方法取SD大鼠32只,随机分为正常组,模型组,参苓白术散高、低剂量组(30,10 g·kg-1),每组8只。采用高脂饲料喂养16周,建立NAFLD大鼠模型,给药组大鼠同时灌服参苓白术散浸膏剂进行干预,16周后取血和肝组织样本,全自动生化仪检测血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、血清丙氨酸转氨酶(ALT)和天门冬氨酸转氨酶(AST)含量;油红O染色观察肝组织脂质蓄积程度;Western Blotting法检测肝组织Nrf2/ARE信号通路相关蛋白(Nrf2)、醌氧化还原酶(NQO1)和血红素氧合酶-1(HO-1)蛋白的表达水平。结果模型组大鼠肝组织油红O染色结果表明肝组织脂质蓄积严重,提示高脂饲料诱导的NAFLD大鼠模型建立成功。与正常组比较,模型组大鼠血清TC、TG、LDL-C、AST水平显著升高(P<0.01),HDL-C水平显著降低(P<0.01);肝组织Nrf2、NQO1、HO-1蛋白表达水平显著升高(P<0.01)。与模型组比较,参苓白术散高、低剂量组大鼠肝组织脂质蓄积程度明显改善,两组血清TC、TG、LDL-C含量及AST水平均呈不同程度下降,血清HDL-C及肝组织Nrf2、NQO1、HO-1蛋白表达水平呈不同程度升高(P<0.05,P<0.01),其中参苓白术散高剂量组变化更为显著。结论参苓白术散能够改善高脂饮食诱导的NAFLD大鼠肝脏脂肪代谢紊乱,减轻肝脏脂质蓄积,其作用机制可能与其激活Nrf2/ARE信号通路有关。

Objective To observe the effects of Shenling Baizhu Powder（SBP）on the nuclear factor erythroid- 2- related factor 2（Nrf2）/antioxidant responsive element（ARE） pathway in liver tissues of nonalcoholic fatty liver disease（NAFLD） rats induced by high fat diet. Methods Thirty- two SPF SD rats were randomly divided into 4 groups,normal control group,model group,high- dose SBP group（30 g·kg^（-1）,ig）,and low- dose SBP group（10 g·kg-1,ig）,8 rats in each group. The rats of NAFLD model were established by feeding a high- fat- diet for 16 weeks,and the SBP treatment groups were simuleaneously fed with high and low dose of SBP extract respectively. After treatment for 16 weeks, blood and liver samples of rats were collected. Total cholesterol（TC）, triglyceride（TG）,high- density lipoprotein cholesterol（HDL- C）,low- density lipoprotein cholesterol（LDL- C）,alanine aminotransferase（ALT）and aspartate aminotransferase（AST）levels in blood serum were detected with automatic biochemical analyzer.The liver tissues were observed after oil red O staining. The protein expression levels of Nrf2,quinine oxidoreductase（NQO1）,and heme oxygenase- 1（HO- 1）in liver tissues were detected by Western blot. Results Compared with the normal control group, severe hepatic lipid accumulation was shown in liver tissues of the model group under microscope after oil red O staining, indicating the successful establishment of NAFLD model. Compared with the normal control group, the serum levels of TC, TG, LDL- C and AST were increased significantly（P〈0.01）,HDL- C level was decreased significantly（P0.01）,and the expression levels of Nrf2,NQO1,and HO- 1 of liver tissues were increased significantly（P〈0.01） in the model group. Compared with the model group,the hepatic lipid accumulation of the two SBP groups was relieved significantly, the serum levels of TC, TG, LDL- C and AST were decreased in different degrees, HDL- C level was increased in different degrees, and the expression levels of Nrf2,NQO1, and HO- 1 of liver tissues were increased in different degrees（P〈0.05, P〈0.01）. High- dose SBP group showed better effect than low- dose SBP group. Conclusion SBP can improve lipid metabolism disorder and reduce hepatic lipid accumulation of the NAFLD rats induced by feeding high- fat diet for 16 weeks,and the mechanism may be related to the activation of Nrf2/ARE pathway in hepatocytes.