蒺藜皂苷对正常和2型糖尿病大鼠餐后血糖水平的影响

目的研究蒺藜皂苷（STT）对正常和2型糖尿病大鼠餐后血糖水平的影响及可能机理。方法正常和2型糖尿病大鼠灌胃蔗糖或葡萄糖,同时灌胃STT,60 min后,尾静脉采血,测定血糖浓度;提取大鼠小肠α-葡萄糖苷酶,体外测定STT对酶活性的抑制作用。结果正常和2型糖尿病大鼠灌胃蔗糖同时灌胃STT 60min后,血糖水平显著低于对照,分别为对照的70.19%（P〈0.001）和68.05%（P〈0.001）,但STT对灌胃葡萄糖后血糖水平的变化无显著性影响;0.1、1、10 mg/mL的STT能够显著抑制α-葡萄糖苷酶的体外活性（P〈0.001）,抑制率分别为20.83%、43.73%和52.62%。结论STT能够显著降低正常和2型糖尿病大鼠餐后血糖水平的升高,其可能机理为对小肠α-葡萄糖苷酶的抑制作用。

Effects of saponins from Tribulus terrestris on postprandial blood glucose levels in normal and type 2 diabetic rats

Objective To study the effects of saponins from Tribulus terrestris（STT）on postprandial blood glucose levels in normal and type 2 diabetic rats and its possible mechanism.Methods STT was co-administered orally with sucrose or glucose to normal and type 2 diabetic rats,at 60 min,blood was collected from tails,postprandial blood glucose levels were measured.Alpha-glucosidase was extracted from small intestine in rats and the inhibitive effect of STT on the enzyme was carried out in vitro.Results STT significantly reduced the 60-min postprandial blood glucose levels which were 70.19%（P〈0.001）and 68.05%%（P〈0.001）of the normal and type 2 diabetic rats respectively,while no significant difference was observed in rats co-administered orally with glucose.Meanwhile,at concentrations of 0.1,1 and 10 mg/mL,STT significantly reduced the activity of α-glucosidase with inhibitory rates of 20.83%,43.73% and 52.62% respectively.Conclusion STT significantly reduce the elevations in postprandial blood glucose levels in normal and type 2 diabetic rats,and the most possible mechanism is the inhibition of the small intestinal α-glucosidase by STT.