南瓜多糖对糖尿病小鼠降血糖作用的实验研究

Study of the Hypoglycemic Effect of the Pumpkin Polysaccharide on Experiment Diabetic Mice

探讨南瓜多糖(Pumpkin Polysaccharide,PP)对实验性高血糖模型小鼠血糖的影响,并研究其降血糖作用的可能机制。采用四氧嘧啶诱发实验性糖尿病动物模型,腹腔注射PP 0.2 g/kg,观察其给药不同时间的血糖、肝糖原、血清胰岛素等指标。结果:PP组灌服腹腔注射7 h后血糖即明显降低,与模型组比较差异极显著(P<0.001)。在注射四氧嘧啶2 h后,模型组和PP组小鼠的血清胰岛素水平均显著下降,但PP组小鼠的肝糖原值保持在正常水平。7 h后,PP组小鼠的血清胰岛素水平与模型组比较显著增加(P<0.01),肝糖原值仍保持在正常水平。同时,PP能降低糖尿病小鼠口服糖负荷后血糖的峰值,并加快已升高的血糖水平回落的速度。PP可对抗四氧嘧啶引起的血糖升高,改善糖耐量,增加肝糖元合成,作用机制可能与其改善胰岛β细胞的功能或增加组织对糖的转化利用有关。

In this study, the effects of the pumpkin polysaccharide（PP） on experimental diabetic mice were carefully investigated and its hypoglycemic mechanism was elucidated through evaluating the effect of 0.2 g/kg PP at various times on serum glucose, glycogen, and insulin in mice with alloxan induced diabetic hyperglycemia. Compared with that of the diabetic model group, 0. 2 g/kg given by PP ip could significantly reduce serum glucose in mice at 7 hours （P〈 0. 001）. Also, it was observed that PP could significantly increase serum insulin level in mice after ip for 7 hours, and kept liver glycogen on normal level at 2 h and 7 h. When PP was given after glucose （2.5 g/kg） could reduced the peak value of blood glucose and speeded up restoration of the increased serum glucose level. The results presented here concluded that PP can significantly inhibit the alloxan induced rise of serum glucose, improve glucose tolerance and increase hepatic glucogen synthesis. The potential mechanism may be is reducing serum glucose is associated with its rehabilitating injured β--cells in the islet or increasing tissue transformation and glucose utilization.