摘要
目的研究蒲公英水提取物降低链脲佐菌素(STZ)致糖尿病大鼠餐后血糖水平的作用及其机制。方法考察蒲公英水提取物400、200、100mg/kg对STZ致糖尿病模型大鼠餐后血糖水平的影响,并采用ELISA法检测各组大鼠血清胰岛素水平;正糖钳实验考察蒲公英水提取物对正常大鼠胰岛素敏感性的影响,检测葡萄糖输注率(GIR);以pNPG为底物,测定蒲公英水提取物400mg/kg体外对α-糖苷酶活性的影响;采用Caco-2细胞单层模拟的小肠上皮模型,评价蒲公英水提取物200、100mg/L对小肠麦芽糖水解和葡萄糖吸收能力的影响。结果蒲公英水提取物400、200、100mg/kg给药7d,可显著降低正常大鼠及STZ致糖尿病大鼠餐后血糖水平,但对血清胰岛素水平、GIR均无影响。蒲公英水提取物对α-糖苷酶活性具有抑制作用,但半数抑制浓度(IC50)高于阳性药阿卡波糖;蒲公英水提取物200mg/L可同时抑制Caco-2细胞单层对麦芽糖的水解和对葡萄糖的转运。结论蒲公英水提取物具有降低餐后血糖的作用,其作用机制与抑制小肠对麦芽糖的水解和对葡萄糖的吸收有关。
Objective To evaluate the hypoglycemic effect of aqueous extract from Taraxaci Herba （AETH） on postprandial blood glucose （PBG） in diabetic rats induced by Streptozotocin （STZ） and to explore the mechanism. Methods The PBG within 120 vain was measured after 7 dig administration of AETH （400, 200, and 100 mg/kg） in normal rats and diabetic model rats induced by STZ, and ELISA was performed to detect the serum insulin of rats in each group. The euglycemic clamp assay was performed to investigate the effect of AETH （400 mg/kg） on the insulin sensitivity in normal rats, and the glucose infusion rate （GIR） was detected： The 50% inhibiting concentration （IC50） against ct-glucosidase was measured in vitro, using pNPG as substrate. Caco-2 cells were preincubated for 72 h with AETH （200 and 100 mg/L）, and then the capacities of Caco-2 monolayer on maltose hydrolysis and glucose absorption were measured. Results The 7 dig administration of AETH decreased the PBG significantly in diabetic rats induced by STZ, but had no effect on serum insulin level and GIR. AETH inhibited ct-glucosidase in vitro, and the IC50 was higher than that of acarbose. AETH （200 mg/L） inhibited the capacities of Caco-2 monolayer on both maltose hydrolysis and glucose absorption. Conclusion AETH has the hypoglycemic effect on PBG in diabetic rats, and the mechanism is related to the inhibition of maltose hydrolysis and glucose absorption in small bowel.
出处
《中草药》
CAS
CSCD
北大核心
2013年第7期863-868,共6页
Chinese Traditional and Herbal Drugs
