摘要
目的:研究大豆异黄酮(soybean isoflavones,SI)和皂甙(soyasaponins,SS)的降糖作用机制.方法: 普通饲料中添加20 g/kg富含SI和SS的大豆胚轴提取物(soybean hypocotyl extracts,SHE),饲喂Wistar正常大鼠和GK/Jcl(Goto-Kakizaki)2型糖尿病大鼠20 w,观察其血糖和葡萄糖耐量变化及对α-葡萄糖苷酶和α-淀粉酶的抑制活性. 结果: 长期食用SHE能显著降低2型糖尿病大鼠血糖水平,明显改善其葡萄糖耐量,同时能改善正常大鼠葡萄糖耐量.在糖尿病相关酶的抑制试验中,B类、E类和DDMP(2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one)皂甙显示很强的α-葡萄糖苷酶抑制活性,其50%抑制浓度(IC50)值为10～40 (mol/L;异黄酮苷元也有很强的α-葡萄糖苷酶抑制作用,其IC50值为20～150 (mol/L,异黄酮葡萄糖苷形式对α-葡萄糖苷酶的抑制活性则较弱.SI和SS还具有较弱的α-淀粉酶抑制作用,浓度为1 g/L时,抑制率为10%～20%.结论: SHE具有降低糖尿病大鼠血糖水平和改善糖耐量的作用,其部分作用机制可能是通过SI和SS对α-葡萄糖苷酶和α-淀粉酶的抑制作用而实现的.
Objective: To study the hypoglycemic effects of soybean isoflavones (SI) and soyasaponins (SS) in diabetes, and their inhibitory activities on alpha-glucosidase (EC 3.2.1.20) and alpha-amylase (EC 3.2.1.1). Methods: GK/Jcl type 2 diabetic rats were given diet containing 20 g/kg of soybean hypocotyl extracts (SHE) for 20 weeks, then the blood glucose and oral glucose tolerance test were observed. SI and SS were isolated by ODS column chromatography and high-performance liquid chromatography (HPLC) from SHE. The inhibitory activities of each component of SI and SS against alpha-glucosidase and alpha-amylase were tested by colorimetric method. Results: SHE decreased blood glucose significantly in type 2 diabetic rats and improved glucose tolerance in both normal and diabetic rats. In alpha-glucosidase inhibitory assay, Group B, Group E and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponins showed potent inhibitory activities with IC50 values of 10-40 靘ol/L. Isoflavone aglycones also showed potent inhibitory activities against alpha-glucosidase with IC50 values of 20-150 mol/L, while isoflavone glycosides showed a little lower potencies. Inhibition of SI and SS on alpha-amylase was low, and their inhibitory activities were about 10%~20% at the concentration of 1g/L. Conclusion: SI and SS may decrease blood glucose and improve oral glucose tolerance in diabetic rats, probably via the inhibitory effects on alpha-glucosidase and alpha-amylase.
出处
《营养学报》
CAS
CSCD
北大核心
2004年第3期207-210,共4页
Acta Nutrimenta Sinica
基金
国家自然科学基金资助项目(No.39960073)
