不同生长期罗汉果提取物对小鼠餐后血糖生成的影响

目的:研究不同生长期罗汉果提取物对小鼠餐后血糖生成的影响,并考察提取物对餐后胰岛素水平及α-葡萄糖苷酶活性的影响.方法:KM种小鼠根据空腹血糖值随机分入浣粉负荷(6g·kg-1)及葡萄糖负荷(2g·kg-1)2种不同糖源组,各糖源负荷组下设空白对照组、糖源对照组、阳性对照组(阿卡波糖0.01g·kg-1)、90 d生长期罗汉果提取物高、中、低剂量组(用药剂量1,0.5,0.25 g·kg-1)、60 d生长期罗汉果提取物高、中、低剂量组(用药剂量1,0.5,0.25 g·kg-1),考察小鼠在连续7d口服不同生长期罗汉果提取物后,进食淀粉及葡萄糖引起的血糖生成情况,以ELISA法测定餐后血清胰岛素水平的变化,并通过体外实验测定不同生长期罗汉果提取物对α-葡萄糖苷酶的抑制作用.结果:90 d和60 d生长期罗汉果提取物均能显著降低动物餐后血糖峰值；所有剂量的90 d生长期罗汉果提取物均显著降低进食淀粉的血糖生成指数(P＜0.05),且0.25 g·kg-1组进食葡萄糖的血糖生成指数也显著降低(P＜0.05)；但60 d生长期罗汉果提取物仅0.5g·kg-1组显著降低进食淀粉的血糖生成指数(P＜0.01),并有降低进食葡萄糖的血糖生成指数的趋势.3个剂量的90 d生长期罗汉果提取物均能极显著地增加餐后胰岛素水平(P ＜0.001),60 d生长期罗汉果提取物对升高餐后胰岛素水平的作用随剂量增加而增加.90 d,60 d生长期罗汉果提取物对α-葡萄糖苷酶活性抑制的IC50分别为11.51g·L-1,2.40 g·L-1.结论:罗汉果提取物有调节机体血糖稳态的作用,增加餐后胰岛素及抑制α-葡萄糖苷酶是其发挥作用的主要途径,不同生长期的罗汉果提取物对血糖影响的作用机制存在差别.

Effect of Siraitiae Fructus Extracts from Different Growth Period Fruit on Postprandial Blood Glucose in Mice

Objective:To study on the effect of Siraitiae Fructus extracts from different growth period fruit on postprandial blood glucose levels in mice,and examine the impact on postprandial insulin and α-glucosidase enzyme activity.Method:Kuenming mice were divided into starch load(6 g · kg-1) and glucose load(2 g · kg-1) group,each group consists of 9 subgroups:normal control,starch load or glucose load control,positive control(acarbose 0.01 g · kg-1),90 days Siraitiae Fructus extracts high,medium and low dose(1,0.5,0.25 g · kg-1),60 days Siraitiae Fructus extracts high,medium and low dose(1,0.5,0.25 g · kg-1).The postprandial blood glucose induced by starch and glucose were observed after 7 days Siraitiae Fructus extracts administration,and the postprandial insulin levels were determined via ELISA method.Moreover,the inhibition effect of Siraitiae Fructus extracts on α-glucosidase activity was determined in vitro.Result:All dosage of 90 days and 60 days Siraitiae Fructus extracts inhibited peak value of postprandial blood glucose;all dosage of 90 days Siraitiae Fructus extracts reduced glycemic index induced by starch(P<0.05),and the glycemic index induced by glucose was reduced at 0.25 g · kg-1(P<0.05);moreover,0.5 g · kg-1of 60 days Siraitiae Fructus extracts significantly reduced glycemic index induced by starch(P<0.01),but all dose of 60 days Siraitiae Fructus extracts only demonstrated a trend to reduce the glycemic index induced by glucose.All dose of 90 days Siraitiae Fructus extracts significantly increased postprandial insulin(P<0.001),and 60 days Siraitiae Fructus extracts increased postprandial insulin dose dependently.The IC50 value of 90 and 60 days Siraitiae Fructus extracts was 11.51 g · L-1 and 2.40 g · L-1,respectively.Conclusion:Mangosteen extract is effectual in the inhibition of the rapid increase of postprandial blood glucose,which are primarily mediated by increasing postprandial insulin levels andα-glucosidase inhibition,there is a difference in hypoglycemic mechanism between Siraitiae Fructus extracts from different growth period fruit.