黄芪多糖保护胰岛β细胞改善大鼠2型糖尿病

Astragalus polysaccharide improves type 2 diabetes mellitus in rats by protecting islet β cells

目的探讨黄芪多糖(APS)对2型糖尿病(T2DM)大鼠胰岛β细胞功能和数量的影响。方法 SD大鼠随机分为正常对照组、T2DM模型组和APS治疗组,每组8只。T2DM模型组大鼠采用高脂饮食联合链脲佐菌素构建T2DM模型,APS治疗组给予APS治疗(每天700mg/kg,APS含量70%)。药物干预8周后处死大鼠,取血测量大鼠的空腹血糖(FBG)、三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)以及空腹胰岛素(FINS)水平,并计算胰岛素分泌指数HOMA-β;取胰腺组织用苏木精-伊红染色观察组织病理学特征,并采用免疫组化法观察并计数胰岛β细胞。结果 (1)与正常对照组比较,T2DM模型组大鼠的FBG、TG和LDL-C升高,HDL-C、FINS和HOMA-β降低(P<0.05);与T2DM模型组比较,APS治疗组大鼠的FBG、TG和LDL-C降低(P<0.05),FINS和HOMA-β升高(P<0.05)。(2)与正常对照组比较,T2DM模型组大鼠的胰岛萎缩,伴有颗粒脱失及空泡变性现象,并且胰岛内β细胞的数量减少(P<0.05);与T2DM模型组比较,APS治疗组大鼠的胰岛体积增大,颗粒脱失和空泡变性现象有所改善,胰岛内β细胞的数量增加(P<0.05)。结论 APS能够改善T2DM大鼠的糖脂代谢,其机制可能是通过保护T2DM大鼠胰岛β细胞,进而促进胰岛素的分泌来实现的。

Objective To explore the effect of AstragaIus polysaceharides （APS） on the function and quantity of islet 13 cells in rats with type 2 diabetes mellitus （T2DM）. Methods SD rats were randomly divided into normal control group, T2DM model group and APS treatment group, with 8 rats in each group. The T2DM rats in the T2DM model group was induced by the combination of high fat diet and streptozotocin, and the rats in the APS treatment group was treated with APS （700 mg kg-1 . d-1, content of APS being 70%）. The rats were sacrificed after 8 weeks of drug intervention, and the serum samples were collected to measure fasting blood glucose （FBG）, triglyceride （TG）, total cholesterol （TC）, high-density lipoprotein cholesterol （HDL-C）, low-density lipoprotein cholesterol （LDL-C） and fasting insulin （FINS）, and to calculate insulin secretion index （HOMA-β value）. Pancreas tissues were extracted and stained with Hematoxylin-Eosin to observe the pancreatic histopathological characteristics, and the quantity of islet β ceils was observed and calculated with immuno-histochemical method. Results （1） Compared with the normal control group, the rats in T2DM model group had significant increases in the FBG, TG and LDL-C, and significant decreases in the HDL-C, FINS and HOMA-β （P〈0.05）; compared with the T2DM model group, the rats in APS treatment group had significant decreases in the FIG, TG and LDL-C （P〈0.05）, and significant increases in the FINS and HOMA-β （P〈0. 05）. （2） Compared with the normal control group, the rats in T2DM model group showed a significant atrophy of the islet accompanied by loss of granular and vacuolar degeneration, and the number of the islet β cells was significantly reduced （P〈0. 05） ; compared with the T2DM model group, the rats in APS treatment group showed a significant increase in the islet volume accompanied by improvement of islet degranulation and vacuolar degeneration, and had a significant increase in the number of islet β cells （P〈0. 05）. Conclusion APS can improve the glucose and lipid metabolisms of the T2DM rats, which may be caused by increasing insulin secretion through the protective effect on pancreatic islet β cells.