柴胡疏肝散对NAFLD大鼠肝脏脂质代谢及AMPK/SIRT1通路的影响

 目的: 观察柴胡疏肝散对高脂饮食建立的非酒精性脂肪性肝病(NAFLD)大鼠肝组织脂质代谢和腺苷酸活化蛋白激酶(AMPK)/sirtuin 1(SIRT1)通路相关蛋白的影响。方法: 选用SPF级SD大鼠24只,随机分为正常(NC)组、高脂(HFD)组和柴胡疏肝散(CSP)组,每组8只。采用高脂饲料喂养大鼠16周建立NAFLD大鼠模型,用药组大鼠同时灌服柴胡疏肝散浸膏剂(9.6 g·kg^-1·d^-1)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和肝匀浆总胆固醇(TC)、甘油三酯(TG)以及血清丙氨酸转氨酶(ALT)和天门冬氨酸转氨酶(AST)含量;HE染色观察肝组织病理损伤变化;油红O染色观察肝组织脂质蓄积程度,透射电镜观察肝细胞内超微结构变化;Western blot法检测肝组织AMPK、磷酸化AMPK(pAMPK)、SIRT1和解偶联蛋白2(UCP2)的蛋白水平。结果: 大鼠肝组织HE染色、油红O染色和电镜结果证实肝细胞脂质蓄积严重,提示NAFLD大鼠模型建立成功。与NC组比较,HFD组血清和肝组织匀浆TC、TG含量显著升高(P < 0.01),血清AST含量显著升高(P < 0.01),肝组织pAMPK和SIRT1蛋白水平显著降低(P < 0.01),UCP2蛋白水平显著升高(P < 0.01);与HFD组比较,CSP组大鼠肝组织脂质蓄积程度明显改善,血清和肝匀浆TC和TG含量呈下降趋势,其中肝匀浆TC和TG含量下降显著(P < 0.05),血清AST含量显著降低(P < 0.05),肝组织pAMPK和SIRT1蛋白水平显著升高(P<0.05),UCP2蛋白水平显著下调(P < 0.01),但各组大鼠总AMPK蛋白水平差异无统计学显著性。结论: 柴胡疏肝散能够改善16周高脂饮食诱导的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AMPK/SIRT1通路有关。

Effects of Chaihu Shugan powder on hepatic lipid metabolism and AMPK/SIRT1 pathway in rats with non-alcoholic fatty liver disease

AIM: To investigate the effects of Chaihu Shugan powder (CSP) on lipid metabolism and the proteins involved in adenosine 5'-monophosphate-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) pathway in the liver tissues of the rats with non-alcoholic fatty liver disease (NAFLD). METHODS: Sprague-Dawley rats were randomly divided into normal control (NC) group, with HFD (HFD) group and CSP group. The NAFLD models were established by feeding with HFD for 16 weeks in the rats. The rats in CSP group were intragastrically administered with CSP extracts (9.6 g·kg^-1·d^-1), and blood and liver samples were collected 16 weeks later. Serum and liver levels of total cholesterol (TC) and triglyceride (TG), and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using an automatic biochemical analyzer. The histological changes of liver tissues were observed with HE staining, while the lipid deposition was observed with Oil Red O staining. The ultrastructural changes of the liver tissues were observed under transmission electron microscope. Moreover, the protein levels of AMPK, phosphorylated AMPK (pAMPK), SIRT1 and uncoupling protein 2 (UCP2) in the liver were detected by Western blot. RESULTS: The results of HE staining, Oil Red O staining and electron microscopy demonstrated that NAFLD rat model was successfully established. Compared with NC group, the serum and liver levels of TC and TG, and serum level of AST in model group were markedly elevated (P < 0.01). Moreover, the protein levels of pAMPK and SIRT1 in HFD group were markedly reduced (P < 0.01), whereas UCP2 level was elevated (P < 0.01). Furthermore, liver levels of TC and TG, and serum level of AST in GSP group were markedly reduced as compared with HFD group (P < 0.05). The protein levels of pAMPK and SIRT1 were elevated (P < 0.05), whereas the UCP2 level was reduced as compared with HFD group (P < 0.01). The protein level of AMPK between the 3 groups had no significant difference.CONCLUSION: CSP attenuates hepatic lipid disorder and hepatic lipid deposition in NAFLD rats induced by feeding with HFD for 16 weeks, which is associated with the activation of AMPK/SIRT1 pathway.