中药复方益糖康对2型糖尿病大鼠肝脏AMPK/SREBP-1C/FAS的影响

Effect of Yitangkang(益糖康)on Hepatic AMPK/SREBP-1C/FAS in Type 2 Diabetic Rats

目的 通过观察中药复方益糖康对2型糖尿病大鼠血脂水平、肝脏形态学变化及肝脏中单磷酸腺苷活化的蛋白激酶(AMP-activated protein kinase, AMPK)/固醇调节元件结合蛋白1C(sterol regulatory element binding protein 1C,SREBP-1C)/脂肪酸合成酶(fatty acid synthetase, FAS) mRNA与蛋白表达的影响,探究益糖康对2型糖尿病大鼠脂代谢的干预作用及机制。方法 SPF级Wistar大鼠32只,随机选取8只为正常对照组予正常饲料喂养,其余大鼠予高脂饲料喂养。4周后,高脂喂养的大鼠予链脲佐菌素(streptozocin, STZ)腹腔注射造模,并随机分为模型组、益糖康组与二甲双胍组(n=8),正常对照组大鼠腹腔注射等量缓冲溶液。益糖康组与二甲双胍组分别予相应药物日1次灌胃治疗,正常对照组与模型组大鼠同期给予等体积生理盐水灌胃。给药6周后,检测大鼠血清总胆固醇(total cholesterol, TC)、甘油三酯(triglyceride, TG)、高密度脂蛋白胆固醇(high-density lipoproteincholesterol, HDL-C)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol, LDL-C)水平以及空腹血糖(fasting blood glucose, FBG)和空腹胰岛素(fasting insulin, FINS)水平,HE与油红O染色观测大鼠肝脏形态学变化与脂质沉积情况,RT-qPCR与Western blot分别检测AMPK/SREBP-1C/FAS mRNA与蛋白的表达情况。结果 与正常对照组相比,模型组大鼠肝脏可见脂肪空泡与炎性细胞浸润,油红着色脂滴沉积,血清FBG、FINS、TC、TG与LDL-C水平显著升高,HDL-C水平显著下降(P<0.01);肝脏AMPK mRNA与蛋白表达显著降低,SREBP-1C、FAS mRNA与蛋白表达显著升高(P<0.05,P<0.01);与模型组相比,益糖康、二甲双胍组肝脏脂肪空泡与炎性细胞浸润减轻,油红着色脂滴减少,血清FBG、FINS、TC、TG与LDL-C水平显著降低,HDL-C水平显著升高(P<0.05,P<0.01);肝脏AMPK mRNA与蛋白表达显著升高,SREBP-1C、FAS mRNA与蛋白表达显著降低(P<0.05,P<0.01)。结论 中药复方益糖康可能通过调控脂代谢相关通路AMPK/SREBP-1C/FAS,上调AMPK,下调SREBP-1C/FAS mRNA与蛋白表达改善2型糖尿病大鼠脂代谢紊乱。

Objective To investigate the intervention effect and mechanism of Yitangkang(益糖康)on lipid metabolism in type 2 diabetic rats by observing the effects of Yitangkang on lipid level,liver morphological changes and expressions of AMP-activated protein kinase(AMPK)/sterol regulatory element binding protein 1c(SREPP-1c)/fatty acid synthetase(FAS)mRNA and protein in liver.s Methods A total of 32 SPF Wistar rats were selected,and 8 rats were selected as the normal control group and fed with normal diet,while the other rats were fed with high-fat diet.Four weeks later,high-fat fed rats were intraperitone-ally injected with streptozotocin(STZ)and randomly divided into model group,Yitangkang group and metformin group(n=8),while the rats of the normal control group were intraperitoneally injected with the same amount of buffer solution.Yitangkang group and metformin group were given the corresponding drug once a day by gavage,while the normal control group and the model group were given the same volume of normal saline by gavage at the same time.After 6 weeks of administration,the levels of blood lipid,fasting blood glucose and insulin were detected.The morphological changes and lipid deposition of the liver were ob-served by HE and oil red O staining.The mRNA and protein expressions of AMPK/SREBP-1C/FAS were detected by RT-qPCR and Western Blot,respectively.s Results Compared with those of the normal control group,fat vacuoles,inflammatory cell in-filtration,oil red colored lipid droplets deposition,serum levels of fasting blood glucose(FBG),fasting insulin(FINS),total cho-lesterol(TC),triglyceride(TG)and low-density lipoprotein cholesterol(LDL-C)were significantly increased,and the serum levels of high-density lipoproteincholesterol(HDL-C)were significantly decreased in the model group(P<0.01).The mRNA and protein expressions of AMPK in liver were significantly decreased,while the mRNA and protein expressions of SREBP-1C and FAS were significantly increased(P<0.05,P<0.01).Compared with those of the model group,the liver fat vacuoles and inflammatory cell infiltration in Yitangkang and metformin groups were alleviated,the oil red colored lipid droplets were de-creased,the serum levels of FBG,FINS,TC,TG and LDL-C were significantly decreased,and the serum levels of HDL-C were significantly increased(P<0.05,P<0.01).The mRNA and protein expressions of AMPK in liver were significantly increased,while the mRNA and protein expressions of SREBP-1C and FAS were significantly decreased(P<0.05,P<0.01).Conclusion Yitangkang may improve the lipid metabolism disorder in type 2 diabetic rats by regulating AMPK/SREBP-1C/FAS,up-regu-lating AMPK and down-regulating SREBP-1C/FAS mRNA and protein expression.