硫辛酸对高脂日粮小鼠脂代谢紊乱及氧化应激的调节作用

为了研究硫辛酸(lipoic acid,LA)对高脂日粮小鼠体内氧化应激、脂类代谢及相关基因表达的影响。采用40只C57BL/6雄性小鼠,随机分为4组:对照组(正常日粮),高脂组(高脂日粮,含20%脂肪),LA组(高脂饲料分别添加0.05%、0.10%LA)。6周后测定小鼠血脂及血浆脂酶水平,全血、消化道及肝脏组织自由基(ROS)水平及肝脏抗氧化酶活性,并采用RT-PCR检测小鼠肝脏Cpt1a及ApoE的表达。结果表明,高脂日粮导致小鼠血脂显著升高、血浆脂蛋白脂酶(LPL)及肝脂酶(HL)活性显著降低(P<0.05);添加0.10%LA可显著降低血脂并提高LPL、HL的活性(P<0.05)。与正常组相比,高脂组血浆和组织中抗氧化相关酶活性显著降低,ROS和丙二醛(MDA)含量显著升高(P<0.05),造成慢性氧化应激;添加LA可显著缓解氧化应激,0.10%LA可使其基本恢复到正常水平。高脂饮食导致小鼠肝脏Cpt1a表达显著下调,ApoE表达显著上调(P<0.05),而添加LA可显著缓解高脂造成的上述基因表达的变化。因此,高脂日粮会导致小鼠体内氧化还原状态失衡,造成脂代谢紊乱,LA可通过清除自由基、调整氧化还原状态,改善小鼠肝脏脂代谢功能。

Effects of Lipoic Acid on Lipid Metabolism Disorder and Oxidative Stress on Mice Feed High-Fat Diet

To explore the effects of lipoic acid(LA) on oxidative stress,the lipid metabolism,and the expression of related gene.C57BL / 6 were randomly divided into four groups,control group,high fat group(HF) and LA group(high fat plus 0.05%LA and 0.1%LA respectively).After 6 weeks,the lipid level,the activity of lipoproteinlipase(LPL) and hepaticlipase(HL) in plasma were determined.Reactive oxygen species(ROS) and the oxidative stress indices of whole blood,gastrointestinal system and liver were also examined.The expressions of ApoE and Cpt1a were analyzed by RT-PCR.Plasma lipid level significantly increased while the activity of LPL and HL significantly declined as induced by high fat diet,and all of them recovered when LA was added.In comparison to control,the ROS and MDA markedly increased while the antioxidant enzymes decreased in HF group,LA group showed the similar trend like control.The expression of Cpt1a decreased and ApoE increased in HF group,while LA group reserved all the changes above.Oxidative stress and lipid metabolism disorder were observed in mice feed high fat diet.LA can improve liver function by altering lipid metabolism through scavenging reactive oxygen species