桑叶水提物对2型糖尿病小鼠花生四烯酸代谢通路的影响

Effects of mulberry leaf water extract on the metabolism of arachidonic acid in type 2 diabetes mellitus mice

本文研究了桑叶水提物(mulberry leaf water extract,MLWE)对2型糖尿病(type 2 diabetes mellitus,T2DM)小鼠花生四烯酸(arachidonic acid,AA)代谢通路的影响,并探讨其对T2DM的防治作用及潜在机制。以链脲佐菌素与高脂高糖(high fat and high sucrose,HFHS)饮食构建T2DM小鼠模型,分为正常对照组(NC)、正常MLWE处理组(NCML)、糖尿病模型组(HFHS)及糖尿病模型MLWE处理组(HSML)。动物福利和实验过程获得徐州医科大学伦理委员会的批准。各组小鼠连续灌胃10周。末次给药后,检测空腹血糖(fasting blood glucose,FBG)及空腹胰岛素(fasting blood insulin,FBI);实时荧光定量PCR(quantitative real time PCR,qPCR)法检测肝脏中AA代谢相关酶的mRNA表达;Western blot法检测肝脏中与AA代谢相关酶的蛋白表达;液质联用法测定血液中AA及相关代谢产物含量。结果显示,NCML组小鼠肝脏中AA相关代谢酶、血液中FBG、胰岛素、AA及代谢产物含量与NC组之间差异无统计学变化;与NC组相比,HFHS组小鼠肝脏中脂肪酸合成酶(fatty acid synthase,Fasn)、磷脂酶A2(phospholipase A2,PLA2)、环氧合酶2(cyclooxygenase-2,COX-2)及脂氧合酶-5(lipoxygenase-5,LOX-5)表达水平、FBG、胰岛素、AA及相关代谢产物水平均显著升高,而肉毒碱棕榈酰基转移酶1A(carnitine palmitoyltransferase 1A,CPT1A)及细胞色素P450酶4A(cytochrome P450 family 4A,CYP4A)表达显著降低。与HFHS组比较,HSML组小鼠肝脏中Fasn、PLA2、COX-2和LOX-5的表达水平,血浆中FBG、胰岛素、AA及相关代谢产物的水平均显著下降,而CPT1A及CYP4A的表达显著增加,提示桑叶水提物可能通过改善T2DM小鼠AA代谢通路异常,发挥其防治糖尿病的作用。

To explore the preventive effects and potential mechanism of mulberry leaf water extract(MLWE)on type 2 diabetes mellitus(T2DM),this study observed the influence of MLWE on the metabolism of arachidonic acid(AA).T2DM mice were induced by high fat and high sucrose(HFHS)diet and intra-peritoneal injection of streptozotocin.The mice were randomly divided into a normal control group treated with drug-free solution(NC group),a normal control group treated with MLWE(NCML group),a diabetes mellitus(DM)group treated with drug-free solution(HFHS group),and a DM group treated with MLWE(HSML group);mice were maintained on this protocol for 10 weeks.Animal experimentation was approved by the Committee on the Ethics of Animal Experiments of Xuzhou Medical University.Mice livers and plasma were collected at the end of experiment.Fasting blood glucose(FBG)and fasting blood insulin(FBI)were detected by kits.The mRNA and protein expression levels of relative metabolic enzymes related to AA in mice livers were respectively detected by quantitative real time PCR(qPCR)andWestern blot.The contents of AA and its relative metabolites in mice plasma were determined by liquid phase chromatography coupled with tandem mass spectrometry.The results showed that there was no significant variation for the relative expression of metabolic enzymes,contents of FBG,FBI,AA,and its relative metabolites between NCML group and NC group.Compared with NC group,the relative expression of fatty acid synthase(Fasn),phospholipase A2(PLA2),cyclooxygenase-2(COX-2),and lipoxygenase-5(LOX-5),and the levels of FBG,FBI,AA,and its relative metabolites in DM group were obviously increased,while that of carnitine palmitoyltransferase 1A(CPT1A)and cytochrome P450 family 4A(CYP4A)were significantly decreased.After intervention with MLWE,those changes could be improved,indicating that MLWE could prevent T2DM by acting on AA metabolism.