瑶药葫芦钻中α-葡萄糖苷酶抑制活性部位的筛选

Screening of the α-Glucosidase Inhibitory Active Part from Yao Medicine Pothos chinensis

目的:从瑶药葫芦钻中筛选出具有α-葡萄糖苷酶抑制活性的有效部位。方法:将葫芦钻水提物依次用石油醚、乙酸乙酯、正丁醇萃取得到不同极性部位,分别测定各部位对α-葡萄糖苷酶的抑制活性,并对筛选出的活性强且得率相对较高的部位进行酶抑制动力学研究;考察各部位对葡萄糖、蔗糖和淀粉负荷小鼠血糖值的影响(以阿卡波糖片为阳性对照)。结果:体外酶活性抑制试验显示,葫芦钻乙酸乙酯部位[得率为0.40%、酶活性抑制率为(72.90±2.85)%]具有较强的α-葡萄糖苷酶抑制活性,且呈现出剂量依赖的快速非竞争性可逆抑制类型。体内耐糖量实验结果表明,阿卡波糖片和葫芦钻各部位对葡萄糖负荷小鼠的血糖值均没有影响(P>0.05),而阿卡波糖片和葫芦钻乙酸乙酯部位能降低蔗糖负荷小鼠30、60 min的血糖值以及淀粉负荷小鼠30、60、120min的血糖值(P<0.05或P<0.01)。结论:乙酸乙酯部位是瑶药葫芦钻中α-葡萄糖苷酶抑制活性的有效部位。

OBJECTIVE： To screen the α-glucosidase inhibitory active part from Pothos chinensis. METHODS： The aqueous extractions of P chinensis were extracted by petroleum, ethyl acetate, n-butyl alcohol in turn to obtain different polarparts. Effect of each part on α-glucosidase inhibitory activity was determined, and enzyme inhibition kinetics was conducted for the screened parts with strong activity and relatively high yield rate; effects of each part on blood glucose level of mice loaded with glucose, sucrose and starch were respectively determined （using Acacoside tablet as positive control）. RESULTS： Enzyme inhibition kinetics in vitro showed the ethyl acetate part [yield rate was 0.40 %, enzyme activity inhibition rate was （72.9±2.85）% ] had strong α-glucosidase inhibitory activity and showed a dose-dependent, fast, non-competitive and reversible model. Results of in vivo glucose tol- erance indicated that Acacoside tablet and each part of P chinensis had no effects on blood glucose level of glucose-loaded mice （P〉0.05） ; while Acacoside tablet and ethyl acetate part in P chinensis could reduce 30, 60 min blood glucose level of sucrose-loaded mice and 30, 60, 120 min blood glucose level of starch-loaded mice （P〈0.05 or P〈0.01）. CONCLUSIONS： Ethyl acetate part is the α-glucosidase inhibitory active part from Yao medicine P. chinensis.