榅桲子不同提取部位对α-葡萄糖苷酶的抑制活性及其降血糖作用

Inhibitory activity on α-D-glucosidase and the hypoglycemic effect of different extracts from Cydonia oblanga seeds

中文关键词:  α-葡萄糖苷酶  榅桲子  糖耐量

英文关键词:α-glucosidase  Cydonia oblanga seeds  glucose tolerance

中文摘要:

      目的 研究榅桲子不同提取部位对α-葡萄糖苷酶的抑制活性及其正常小鼠糖耐量的影响。方法 以4-硝基酚基α-D-吡喃葡萄糖苷(4-nitrobenzophenone-α-D-glucopyr anoside, PNPG)为底物, 测定榅桲子乙酸乙酯、正丁醇、水部位α-葡萄糖苷酶的抑制活性, 并对筛选出的活性强的部位进行酶动力学研究; 考察各部位对蔗糖负荷小鼠糖耐量的影响。结果 酶活性抑制实验显示, 榅桲子乙酸乙酯部位及水部位对α-葡萄糖苷酶的抑制活性最强(IC50值分别为43.1、5.8), 且乙酸乙酯部位抑制类型属于混合型抑制, 水部位抑制类型属于竞争性抑制。糖耐量实验结果表明, 榅桲子乙酸乙酯、水部位在15、30、60 min明显降低蔗糖负荷的正常小鼠糖耐量, 且其作用比阿卡波糖强。结论 榅桲子乙酸乙酯、水部位中含有抑制α-葡萄糖苷酶活性的成分, 可用于糖尿病治疗。

英文摘要:

      Objective To investigate the inhibitory activity of different extracts from Cydonia oblanga seeds on α-glucosidase and its glucose tolerance in normal mice. Methods 4-nitrobenzophenone-α-D-glucopyr anoside (PNPG) was used as a substrate to measure the inhibition of α-glucosidase activity by ethyl acetate, n-butanol and water extracts of Cydonia oblanga seeds and the enzyme inhibition kinetics was conducted for the screened extracts with strong activity. Effects of each extract on glucose tolerance of mice loaded with sugar were respectively determined. Results Enzyme inhibition kinetics showed that ethyl acetate and water extracts had strong α-glucosidase inhibitory activity (IC50 values were 43.1 and 5.8), the ethyl acetate extract showed a mixed inhibition model and the water extract showed competitive and reversible model. The results of glucose tolerance test showed that ethyl acetate and water extracts in 15, 30, 60 min significantly decreased sugar tolerance in normal mice with sucrose load, and the effects were stronger than acarbose. Conclusion It suggests that the ethyl acetate and water extracts from Cydonia oblanga seeds have an inhibitory activity on α-glucosidase and may be useful in diabetes treatment.