淫羊藿苷介导AMPK/PGC-1α/GLUT4通路对高脂诱导的大鼠非酒精性脂肪肝损伤和脂代谢的调节作用

Regulatory effects of icariin-mediated AMPK/PGC-1α/GLUT4 pathway on injury and lipid metabolism of high-fat-induced nonalcoholic fatty liver disease

目的探究淫羊藿苷(ICA)介导AMPK/PGC-1α/GLUT4通路对高脂诱导的大鼠非酒精性脂肪肝(NAFLD)损伤和脂代谢的调节作用。方法50只SD大鼠随机分为对照组(Control组),模型组(NAFLD组),淫羊藿苷低、中、高剂量组(20 mg/kg、40 mg/kg、80 mg/kg ICA),10只每组。Control组大鼠常规饮食喂养,剩余4组采用高脂饲料喂养方式建立NAFLD模型,12周后进行给药治疗。采用全自动生化分析仪分析血清中总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白(HDL)及低密度脂蛋白(LDL)含量;HE染色观察肝脏组织形态;ELISA法检测肝脏乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)含量;Western blot检测Bcl-2和Bax蛋白的表达;免疫组化检测肝脏肿瘤坏死因子-α(TNF-α)、白介素6(IL-6)阳性表达。结果相比较于Control组,NAFLD组大鼠血清TC、TG及LDL含量均升高,而HDL含量降低(P<0.05);肝脏组织SOD含量及Bcl-2、AMPKα1、PGC-1α、GLUT4及CPT-1蛋白相对表达量均降低,而MDA、LDH含量,Bax、ACC蛋白相对表达量及TNF-α及IL-6阳性细胞数占比均升高(P<0.05)。相比较于NAFLD组,ICA各给药组大鼠血清TC、TG及LDL含量均降低,而HDL含量升高(P<0.05);肝脏组织SOD含量及Bcl-2、AMPKα1、PGC-1α、GLUT4及CPT-1蛋白相对表达量均升高,而MDA、LDH含量,Bax、ACC蛋白相对表达量及TNF-α及IL-6阳性细胞数占比均降低(P<0.05),且均呈剂量依赖性。结论ICA对高脂诱导的大鼠非酒精性脂肪肝损伤具有明显的改善作用,其可能通过介导AMPK/PGC-1α/GLUT4通路调节脂代谢,发挥对肝脏的保护作用。

Objective To explore the regulatory effects of icariin(ICA)-mediated AMPK/PGC-1α/GLUT4 pathway on injury and lipid metabolism of high-fat-induced nonalcoholic fatty liver disease(NAFLD).Methods 50 SD rats were randomly divided into control group(Control group),model group(NAFLD group)and low-,medium-and high-dose icariin groups(20,40,80 mg/kg ICA),with 10 rats in each group.Control group was fed a regular diet,and the remaining four groups were fed with high-fat diet to establish NAFLD models,and given drugs after 12w.Levels of serum total cholesterol(TC),triglyceride(TG),high density lipoprotein(HDL)and low density lipoprotein(LDL)were analyzed by automatic biochemical analyzer.Liver tissue morphology was observed by HE staining.Levels of lactate dehydrogenase(LDH),malondialdehyde(MDA)and superoxide dismutase(SOD)in liver were detected by ELISA,and the protein expression was detected by Western blot,and immunohistochemistry was used to detect the positive expression levels of liver tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).Results Compared with control group,levels of serum TC,TG and LDL in NAFLD group were increased while the level of HDL decreased(P<0.05).The SOD level and protein relative expression levels of Bcl-2,AMPKα1,PGC-1α,GLUT4 and CPT-1 in liver tissues decreased while the levels of MDA and LDH,protein relative expression levels of Bax and ACC and positive cells quantities of TNF-αand IL-6 were increased(P<0.05).Compared with NAFLD group,the serum levels of TC,TG and LDL of ICA rats in drug administration groups decreased while the HDL level was increased(P<0.05).The SOD level and protein relative expression levels of Bcl-2,AMPKα1,PGC-1α,GLUT4 and CPT-1 increased while the levels of MDA and LDH,protein relative expression levels of Bax and ACC and positive cells quantities of TNF-αand IL-6 decreased(P<0.05),and they showed dose-dependence.Conclusion ICA can significantly improve the non-alcoholic fatty liver injury induced by high fat,and it can regulate the lipid metabolism by mediating the AMPK/PGC-1α/GLUT4 pathway,and play a protective role in the liver.