AIM To explore the protective effects and mechanisms of dihydromyricetin (DHM) against non-alcoholic fatty liver disease (NAFLD) in ApoE-/-mice.METHODS The 40 male healthy six week-old ApoE-/mice were randomly divided into model group,DHM (50,100 mg/kg) group and Bicyclol group.Ten male C57 mice were used as the control group.The control and model groups were administrated with 0.5％ CMC-Na solution and the other three groups were given DHM [50,100 mg/(kg-d),i.g.] and Bicyclol [140 mg/(kg · d),i.g.].All mice were fed with high fat diet (0.3％ cholesterol,20％ fat) for 12 weeks.At the end of the experiment,the blood was collected from the orbit and the serum was separated for blood lipid detection.AST and ALT expression levels were detected by automatic biochemical analyzer.HE staining and oil red O monitored the liver injury and lipid accumulation.The oxidase enzymes were measured by the commercial kits.The hepatocyte apoptosis was determined by TUNEL assay,and the Bcl-2,Caspase-3 expression levels were detected by immunohistochemistry.The AMPK and phosphorylation of AMPK expression levels were determined by Western blot.RESULTS After the treatment,liver lipid accumulation and liver injury,TUNEL postive cells sharply increased compared with the control group.Meanwhile,the Caspase-3 expression level was significantly upregulated and the Bcl-2 was markedly downregulated in the model group.DHM [50,100 mg/(kg · d)] remarkably reduced AST and ALT levels,liver lipid accumulation and TUNEL positive cells and modulated oxidase enzymes expression level compared with the model group.Moreover,DHM obviously increased Bcl-2 expression and decreased Caspase-3 expression in liver tissue,and inhibited AMPK phosphorylation.CONCLUSION DHM reduces the lipid accumulation and protects liver injury from high fat diet induced NAFLD mice,the protective mechanism of DHM may be related to inhibiting AMPK phosphorylation and inhibiting hepatocyte apoptosis.%目的 本研究探讨二氢杨梅素对高脂诱导的非酒精性脂肪肝小鼠的保护作用及作用机制.方法 取健康雄性ApoE-/-小鼠40只,随机分为4组,即模型组,二氢杨梅素低、高剂量组,双环醇组,每组10只;另取10只C57小鼠作为对照组.对照组与模型组予以0.5％羧甲基纤维素钠溶液灌胃0.2 mL/10 g,二氢杨梅素分别以50、100 mg/(kg·d)混悬液灌胃,双环醇组以140 mg/(kg·d)混悬液灌胃.高脂饲料(0.3％胆固醇,20％脂肪)持续饲养12周后,测量各组小鼠的体质量,眼眶取血,分离血清.生化仪检测血脂四项、AST、ALT水平.HE染色观察肝脏病理学改变,油红0染色观察肝细胞内脂质沉积状况;试剂盒检测氧化酶的表达;TUNEL实验检测肝脏细胞凋亡情况,应用免疫组化检测肝脏Bcl-2和Caspase-3的表达.Western评价肝脏腺苷酸活化蛋白激酶(AMPK)磷酸化水平.结果 连续灌胃12周后,与对照组相比,模型组小鼠表现出肝脏脂肪变性并伴肝脏氧化损伤;同时TUNEL阳性细胞数增多,肝脏中Caspase-3表达升高且Bcl-2含有量减少;肝组织内AMPK磷酸化水平显著升高.与模型组比较,二氢杨梅素高、低剂量组和双环醇组可改善AST和ALT水平,减轻各治疗组小鼠肝脏脂肪变性,调控氧化酶的表达,降低TUNEL阳性细胞数,提高肝脏中Bcl-2和减少Caspase-3的表达,降低肝组织内AMPK磷酸化水平.结论 二氢杨梅素能够降低肝脏脂质沉积,保护肝损伤从而改善高脂饲料诱导的ApoE-/-小鼠非酒精性脂肪肝,其机制可能与其通过下调AMPK磷酸化水平进而抑制肝细胞凋亡有关.
展开▼
