玉米须水提物对2型糖尿病大鼠胰岛β细胞功能的影响

Protective effect of aqueous extract of stigma maydis on pancreatic islet β cell in type 2 diabetic rats

目的探讨玉米须水提物对T2DM大鼠胰岛β细胞功能的影响。方法水溶提取法制备玉米须水提物(主要成分为玉米须多糖)。采用高脂高糖饲养加小剂量链脲佐菌素(STZ)诱导T2DM雄性SD大鼠模型,将实验动物分为正常对照组、模型对照组,以及玉米须水提物低、中、高剂量组和二甲双胍组,共6组。给药8周后,测定各组大鼠空腹血糖(FBG)、体重(BW)和空腹胰岛素(FIns),计算HOMA-IR和HOMA-β,免疫组化法分析胰岛中胰岛素表达水平,并作HE染色观察。结果与模型组比较,中、高剂量的玉米须水提物可呈剂量依赖型显著降低糖尿病大鼠FBG、BW和FIns的水平(P<0.05或P<0.01),明显降低大鼠HOMA-IR(P<0.05或P<0.01),显著升高HOMA-β(P<0.05或P<0.01),明显增强胰岛细胞中胰岛素表达(P<0.05或P<0.01)。结论玉米须水提物能改善T2DM大鼠胰岛素低抗和胰岛β细胞功能。

Objective To investigate the protective effect of stigma maydis aqueous extract（SMAE） on pancreatic islet β cell in type 2 diabetic rats. Methods Method of aqueous extract was used for preparing the SMAE （main functions of stigma maydis were from polysaccharide）. Type 2 diabetic male Sprague-Dawley rat mode was induced by high-fat and high-sugar diet and low dose streptozotocin （STZ） βRats were randomly divided into normal control group, model control group, SMAE groups as low, middle and high dose and positive control group（metforrnin ）. After 8 weeks of treatment ,levels of fasting blood glucose（FBG） ,body weight（BW）and fasting insulin （Fins） were assayed. Homeostasis model assessment （HOMA） of insulin resistance and β cell function were calculated. Immunohistocmical stain was adopted to analyze the expression of insulin in islet cells. Moreover, HE staining was used to observe morphology of islets. Results Compared with model control group,SMAE at middle and high dose remarkably lowered FBG, BW and Fins in dose-dependent manner （P〈0. 05 or P〈0. 01）, lowered HOMA-IR（P〈0.05 or P 〈0. 01）, improved the HOMA-β（P〈0. 05 or P〈0. 01）, augmented the expression of insulin in islet cells （P〈0.05 or P〈0. 01）, and repaired the damaged β cell. Conclusions SMAE can partly repair the damaged β cells, and ameliorate the function of islet β cells in type 2 diabetic rats.