桑叶总黄酮对糖尿病大鼠小肠双糖酶的抑制作用

目的 观察桑叶总黄酮对糖尿病大鼠的降糖作用及其对大鼠双糖酶活性的影响。方法 糖尿病大鼠灌胃给桑叶总黄酮，观察给药前后血糖变化；剥离小肠刷状缘膜，匀浆后加桑叶总黄酮测定对双糖酶活性的抑制率；大鼠小肠注入麦芽糖，30、60、120分钟后取门静脉、外周静脉血，测门－外周静脉血糖差。结果 桑叶总黄酮使糖尿病大鼠血糖降低；对蔗糖酶、麦芽糖酶、乳糖酶活性抑制率依次达68.0%、47．1％、27．8％；使注入麦芽糖后门－外周静脉血糖浓度差降低。结论 桑叶总黄酮通过抑制大鼠小肠双糖酶活性有显著的降血糖作用。

Inhibitory effect of total flavonoids from mulberry tree leaf on small intestine disaccharidases in diabetic rats

Objective To observe the hypoglycemic effect of total flavonoids from mulberry tree leaf (MTF) on diabetic rats and the effect of MTF on disaccharidases from rats. Methods Diabetic rats were treated with MTF, and then the change of blood glucose of these rats was observed; the brush border membrane from the small intestine of rats was stripped and homogenized, which was incubated with MTF and disaccharides, and the inhibitory rate of MTF on disaccharidases was determined. Blood samples from portal and peripheral veins were separately collected at 30, 60, 120 min after maltose solution was infused into small intestine in vivo, then the difference of blood glucose concentration between portal and peripheral veins was determined. Results MTF exerted a hypoglycemic effect on diabetic rats by inhibition of disaccharidases, the inhibitory rate of sucrase, maltase and lactase was 68.0%, 47.1%, 27.8% respectively, the difference of blood glucose concentration between portal and peripheral veins was also reduced. Conclusion The hypoglycemic effect of MTF on diabetic rats is probably via the inhibitory effect on small intestine disaccharidases in rats.