目的:观察南苜蓿总皂苷(TSMP)对2型糖尿病(T2DM)大鼠血糖、血脂、氧化应激的影响。方法:采用高糖高脂饲料喂养4周加小剂量的链脲佐菌素(30 mg·kg^-1)的方法建立2型糖尿病大鼠模型,将50只模型大鼠随机分为模型组,二甲双胍组(0.2 g·kg^-1),南苜蓿总皂苷高剂量组(2.8 g·kg^-1)、中剂量组(1.4 g·kg^-1)、低剂量组(0.7 g·kg^-1),连续灌胃4周,末次给药后测定空腹血糖(FBG)、总胆固醇(TCH)、三酰甘油(TG)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)、空腹胰岛素(FINS)、糖化血红蛋白(HbA1c)、丙二醛(MDA)、超氧化物岐化酶(SOD),免疫组化法观察胰岛素和胰高血糖素的表达。结果:与模型组比较,南苜蓿总皂苷2.8,1.4 g·kg^-1能显著降低实验性2型糖尿病大鼠给药后7,8周的FBG水平(P〈0.01或P〈0.05);降低TCH、TG、LDL-C的水平(P〈0.01或P〈0.05),升高HDL-C的水平含量(P〈0.05);降低FINS和HbA1c水平(P〈0.01或P〈0.05);降低MDA含量(P〈0.01);升高SOD含量(P〈0.01);增加胰岛素阳性表达,减少胰高血糖素阳性表达。结论:南苜蓿总皂苷对2型糖尿病模型大鼠具有降低血糖,调节血脂,抗氧化,保护胰腺功能的作用。
OBJECTIVE To observe effects of total saponins from Medicago polymorpha(TSMP)on blood glucose,lipid and antioxidant activity,as well as improvement of pancreatic islet cell functions.METHODS Rat models of type 2 diabetes were established by feeding rats with high glucose and fat diets and intraperitoneally injecting STZ30 mg·kg^-1.Rats were divided into five groups:control,model,metformin,TSMP2.8 g·kg^-1,1.4 g·kg^-1 and 0.7 g·kg^-1,and all rats were medicated for four weeks.At the end of medication,blood samples were collected to determine fasted blood glucose(FBG),total cholesterol(TCH),triglyceride(TG),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),fasted serum insulin(FINS),HbA1 c,malondialdehyde(MDA)and superoxide dismutase(SOD).Insulin and glucagon protein expression were detected by immunohistochemistry.RESULTS Compared with model group,TSMP1.4 g·kg^-1 decreased FBG level(P〈0.01 or P〈0.05),contents of TCH,TG and LDL-C(P〈0.01 or P〈0.05),FINS and HbA1 c levels(P〈0.01 or P〈0.05),content of MDA(P〈0.01).TSMP 1.4 g·kg^-1 increased contents of SOD and HDL-C.Insulin immunoreactive cells decreased,but glucagon increased.CONCLUSION TSMP can decrease blood glucose,adjust blood lipids,resist oxidization and protect pancreatic functions.