桑叶不同提取部位对α-葡萄糖苷酶抑制活性体外研究

α-glucosidase inhibition by different extracts of folium mori in vitro assay

目的建立体外α-葡萄糖苷酶抑制活性评价体系,观察桑叶不同提取物对α-葡萄糖苷酶的抑制作用。方法经大鼠小肠获得α-葡萄糖苷酶,以4-硝基苯基-α-D-吡喃葡萄糖苷(p NPG)为底物,以阿卡波糖(Acarbose)为阳性对照,测定桑叶水提液(WE)、水提上清液(AP-A)、水提沉淀(AP-P)及75%乙醇提取液(EE)对α-葡萄糖苷酶活性抑制作用。结果桑叶不同提取液均有α-葡萄糖苷酶抑制活性,不同提取液的半数抑制浓度(IC50)分别是WE:0.08 g/L;AP-A:0.17 g/L;AP-P:0.42 g/L;EE:0.12 g/L;桑叶提取液α-葡萄糖苷酶抑制活性强弱顺序为:WE>AP-A>EE>AP-P,其中WE IC50小于Acarbose(0.11 g/L)。结论桑叶水提液抑制α-葡萄糖苷酶活性作用最强,为桑叶在该机制发挥降糖作用的主要活性部位,体外α-葡萄糖苷酶活性抑制评价体系可作为该药效成分筛选平台。

Objective To establish α-glucosidase inhibitory activity evaluation in vitro system, and study the activity of α-glucosidase inhibitation of different mulberry extracts. Methods The experiment was car- ried out with 4-nitro phenol-u-D-glucopyranoside （pNPG） as substrate to measure water extract of mul- berry leaves （WE）, water extraction supernatant （AP-A）, precipitation （AP-P） and 75% ethanol extract （EE） for the inhibitory activity of a-glucosidase obtained from small intestine in rats. Results All mul- berry leaves extracts have a-glucosidase inhibitory activity, and the concentrations of IC50 of the extracts are as follows： WE：0.09 g/L;AP-A： 0.18 g/L; AP P： 0.40 g/L; EE： 0.25 g/L; that is, WE〉AP-A〉EE 〉AP-P, where IC50 of WE was less than Acarbose （0.16 g/L）. Conclusion The water extraction of mul- berry leaf has the strongest α-glucosidase inhibition activity which plays the role on the mechanism of hy- poglycemic as principal components. The evaluation system of α-glucosidase inhibition activity in vitro pro- vided a platform for screening the compounds of u-glucosidase inhibition.