n-3多不饱和脂肪酸对大鼠非酒精性脂肪肝的改善作用

Improvement effect of n-3 polyunsaturated fatty acid on rat nonalcoholic fatty liver disease

目的探讨n-3多不饱和脂肪酸(n-3PUFA)对高脂诱导的Wister大鼠非酒精性脂肪性肝(NAFLD)的改善作用。方法 Wister雄性大鼠30只,分为正常组、模型组、n-3PUFA组。采用高脂喂养建立NAFLD模型,实验20周后,每组抽出7只大鼠检测血清及肝脏总胆固醇(TG)及三酰甘油(TC);其余3只大鼠肝脏苏木精-伊红(HE)染色;应用实时定量PCR(Real timeqPCR)及Western blot检测肝脏组织单核细胞趋化蛋白-1(MCP-1)、诱导型一氧化氮合酶(iNOS)、肿瘤坏死因子-α(TNF-α)mRNA及蛋白水平。结果模型组大鼠血清及肝脏TG、TC水平明显高于对照组(P<0.01),加入n-3PUFA后血清及肝脏的TG、TC水平明显下降(P<0.05)。HE染色能明显观察到模型组大鼠肝细胞脂肪变性,而n-3PUFA有明显改善效果。模型组大鼠炎症分子MCP-1、iNOS、TNF-α基因表达水平明显高于对照组(P<0.05),而n-3PUFA组与模型组比较,MCP-1、iNOS、TNF-α炎症分子的表达水平明显下降(P<0.05)。结论高脂喂养能引起大鼠肝脏严重的脂肪变性及炎性反应,而n-3PUFA起明显的改善作用。

Objective To investigate the improvement effect of n-3 polyunsaturated fatty acid （n-3 PUFA） on rat nonalco- holic fatty liver disease（NAFLD） induced by high fat diet. Methods Thirty Wister male rats were divided into the control group, model group and n-3 PUFA group. The high fat feeding was adopted to establish NAFLD model. After 20 weeks of experiment, 7 cases were extracted from each group for detecting serum and liver total cholesterol （TC） and triacylglyceride（TG） ;other 3 cases were performed the liver HE staining, the levels of MCP-1, iNOS, TNF-α mRNA protein were detected by using the Real time quan- titative PCR（qPCR） and Western blot. Results The TC and TG levels in serum and livers of the model group were significantly higher than those in the control group（P〈0.01） ,but which were evidently decreased after adding n-3 PUFA（P〈0.05）. The HE staining clearly observed the rat hepatic cells fatty degeneration in the model group, while polyunsaturated fatty acid had obvious improvement effect on it. The inflammatory molecule MCP-1 ,iNOS, TNF-α gene expression levels in the model group were signifi- cantly higher than those in the control group（P〈0.05）, while the expression levels of MCP-1,iNOS and TNF-α in the n-3PUFA group were significantly decreased compared with the model group. Conclusion High fat feeding can cause the severe fatty degener- ation in rat liver, but polyunsaturated fatty acid can play obvious improvement effect.