茼蒿对2型糖尿病大鼠糖脂代谢及抗氧化作用的影响

EFFECTS OF GARLAND CHRYSANTHEMUM ON GLUCOSE AND LIPID METABOLISMS AND ANTIOXIDANT ABILITY IN TYPE 2 DIABETES RATS

目的探讨茼蒿对2型糖尿病(type2diabetesmellitus,T2DM)大鼠血糖、血脂的影响及机制。方法高脂饮食联合链脲佐菌素(streptozocin,STZ)诱导T2DM大鼠模型,随机分为正常对照组(NC)、模型组(MC)和茼蒿高(HCCL,4.26g/kg)、中(MCCL,2.84g/kg)、低(LCCL,1.42 g/kg)干预组,模型成功后,灌胃4w后处死,观察一般情况,测空腹血糖(fasting blood glucose,FBG)、血清甘油三酯(TG),总胆固醇(TC),低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C),肝组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)活性。RT-PCR、Western bloting法检测肝组织中过氧化物酶体增殖物激活受体γ(peroxisome proliferators-activated receptorγ,PPARγ)mRNA的表达和PPARγ蛋白含量。结果(1)模型组血清TC、TG、LDL-C水平较正常组均显著升高(P<0.01),HDL-C水平显著降低(P<0.01);与模型组相比,茼蒿低、中、高剂量组的TC、TG、LDL-C水平均显著降低,(P<0.05,P<0.01),而HDL-C水平则显著升高(P<0.05,P<0.01),高剂量组显著优于低剂量组。(2)模型组大鼠肝脏中SOD和GSH-Px的活性降低。与模型组相比,茼蒿低、中、高剂量组的SOD、GSH-Px水平均显著升高(P<0.05,P<0.01)。模型组MDA含量明显高于正常对照组,茼蒿低、中、高剂量组肝中MDA含量均显著下降(P<0.05,P<0.01)。(3)模型组PPARγmRNA表达下调,蛋白含量下降,与模型组比茼蒿中、高剂量组表达升高(P<0.05,P<0.01),高剂量组优于低剂量组。结论茼蒿对2型糖尿病具有干预作用,可能是通过增强肝细胞抗氧化能力而改善肝脏脂代谢障碍,同时提高PPARγ活性,增强其蛋白表达而实现的。

Objective To investigate the effect and underlying mechanism of garland chrysanthemum extracts on the level of blood glucose and lipids in type 2 diabetes rats. Methods The rats were randomly divided into 3 groups： control group, model group and treatment group. Type 2 diabetes model was induced by combination of STZ and high-fat diet. The rats of treatment group were administered intragastrically with different doses of garland chrysanthemum extracts （4.26, 2.84 and 1.42g/kg）, After 4 weeks treatment, the rats were sacrificed to detect the concentration of TC, TG, LDL-C and HDL-C in serum. Furthermore, the levels of SOD, GSH-Px and MDA, as well as the gene and protein expression of PPAR＇/in liver tissue were investigated. In addition, the fasting glucose Value was measured. Results （1） Compared to the control, the levels of TC, TG and LDL-C were obviously increased, whereas, the concentration of HDL-C significantly decreased. The levels of TC, TG and LDL-C in the treatment group were conspicuously lower than those in the model gi＇oup. On the contrary, the concentration of HDL-C was the higher than that in the model group. Meanwhile, high dose of garland chrysanthemum extracts showed more obvi0usly effect on the levels of TC, TG, LDL-C and HDL-C than middle and low doses of garland chrysanthemum extracts. （2） The activities of SOD and GSH-Px in model rats were obviously lower than control rats. The levels of SOD and GSH-Px in treatment group were significantly higher than in model group. Additionally, the concentration of MDA in model group was significantly higher than in control group, and the concentration of MDA in treatment group was lower than was in model group. （3） The gene and protein expression of PPARy in model group was conspicuously decreased compared with control group, while the expression in treatment group obviously higher than in model group. The high doses of garland chrysanthemum extracts showed more obviously upregulation on the expression of PPARy than middle and low doses of garland chrysanthemum extracts. Conclusion Our study indicated that Garland chrysanthemum can benefit in the treatment of type 2 diabetes by enhancing the antioxidant ability of the liver, elevating the activity and expression of PPAR γ .