蜂胶和杨树胶中黄酮类成分及其抑制α-葡萄糖苷酶活性研究
Flavonoids in propolis and poplar resin and their inhibition of α-glucosidase activity

通过乙醇提取、液液萃取结合柱层析分离得到河南蜂胶和杨树胶中不同极性组分，利用高效液相色谱分析判定分离效果、确定分离成分；采用α-葡萄糖苷酶抑制剂筛选模型评价各分离组分的体外降血糖活性；通过链脲佐菌素诱导的小鼠高血糖模型进行口服糖耐量实验，评价该分离组分体内抑制肠道内α-葡萄糖苷酶的功效。结果显示，蜂胶及其同源杨树胶的50%乙醇洗脱组分体外抑制α-葡萄糖苷酶效果最优，IC50值分别为39.03±2.76和28.28±3.79 μg/mL，并能有效抑制糖尿病小鼠肠内α-葡萄糖苷酶活性，显著降低糖尿病小鼠的餐后血糖水平，有利于血糖水平恢复和保持血糖稳定；高效液相色谱分析结果发现，蜂胶及其同源杨树胶的50%乙醇洗脱组分中皆含有槲皮素、山奈酚、异鼠李素、芹菜素、白杨素和高良姜素等黄酮类化合物。 
Through ethanol extraction and liquid-liquid extraction combined with column chromatography,the different components in Henan propolis and the poplar resin were isolated.The separation effect and the separation components was determined by high performance liquid chromatography(HPLC).The in vitro hypoglycemic activity of each isolated fraction was evaluated by the α-glucosidase inhibitor screening model,at the same time,oral glucose tolerance test (OSTT) was carried out in hyperglycemia mouse model induced by streptozotocin(STZ) to further verify the inhibitory effect of the isolated fraction α-glucosidase efficacy in the intestines.The results showed that the 50% ethanol elution fraction of propolis and its homologous poplar resin extract had the best inhibitory effect on α-glucosidase in vitro,their IC50 are 39.03±2.76 μg/mL and 28.28±3.79 μg/mL.On the other hand,this component could effectively inhibit the intestinal α-glucosidase activity in diabetic mice (P<0.05),conduciving to the recovery of blood glucose and maintain the blood sugar stability.Liquid chromatographic analysis showed that the 50% ethanol component of propolis and its homologous poplar resin both included quercetin,apigenin,kaempferol,chrysin,isorhamnetin and galangin and other flavonoids compound.