金荞麦根茎乙醇提取物抗氧化和对α-葡萄糖苷酶、α-淀粉酶的抑制作用

Study the in vitro antioxidant and α-glucosidase,α-amylase inhibitory activities of extracts of Fagopyri dibotryis rhizoma

目的:研究金荞麦根茎乙醇提取物不同极性部位的体外抗氧化活性和α-葡萄糖苷酶、α-淀粉酶的抑制活性。方法:采用系统溶剂法梯度萃取金荞麦乙醇提取液,以获取不同极性部位的金荞麦提取物;采用DPPH、羟自由基和ABTS自由基清除实验对金荞麦根茎乙醇提取物不同极性部位的抗氧化活性进行研究,并以α-葡萄糖苷酶和α-淀粉酶为药物靶点,4-硝基苯-α-D-吡喃葡萄糖苷和淀粉为底物,阿卡波糖为阳性对照,筛选对α-葡萄糖苷酶和α-淀粉酶具有抑制作用的金荞麦根茎乙醇提取物部位。结果:在0~0.2mg/ml浓度范围内,金荞麦根茎乙醇提取物的乙酸乙酯萃取部位对DPPH、羟自由基和ABTS自由基具有很强的清除作用,但略低于维生素C的清除作用。在25mg/ml相同浓度下,金荞麦根茎乙醇提取物中正丁醇萃取部位、乙酸乙酯萃取部位和氯仿萃取部位对α-葡萄糖苷酶的IC50值均低于阳性对照阿卡波糖的IC50值,且抑制率均大于阿卡波糖的抑制率,乙酸乙酯萃取部位对α-淀粉酶的抑制率大于阿卡波糖的抑制率。在25mg/ml相同浓度下,金荞麦根茎乙醇提取物的5个不同萃取部位中,乙酸乙酯萃取部位对α-葡萄糖苷酶和α-淀粉酶的抑制作用最强(抑制率分别为为87.32%、84.57%)。在0~50mg/ml浓度范围内,金荞麦根茎乙醇提取物的不同萃取部位对α-葡萄糖苷酶和α-淀粉酶的抑制作用均呈剂量依赖关系。结论:金荞麦根茎乙醇提取物的乙酸乙酯萃取部位具有很好的抗氧化作用和α-葡萄糖苷酶、α-淀粉酶的抑制作用。

Objective：To study in vitro antioxidant activity and α-glucosidase, α-amylase inhibitions of the extracts of Fagopyri Dibotryis Rhizoma. Methods ： Antioxidant and free radical scavenging activities of the extracts of F. Dibotryis Rhizoma were determined by DPPH, hydroxyl free radical and ABTS free radical-scavenging assay. By establishing α-glucosidase and amylase screen inhibitory model, the activity of extracts of F. Dibotryis Rhizoma was screened. The relationship of inhibitory ratio and the extract concentration was also studied. Results：At the con- centration range of 0 ~ 0. 2mg/ml, among five extracts of F. Dibotryis Rhizoma, ethyl acetate extract showed significant DPPH radical scaven- ging activitity, hydroxyl free radical scavenging activity and ABTS free radical scavenging activity. At the concentration of 25mg/ml, butyl al- cohol extract, ethyl acetate extract and chloroform extract showed strong inhibitory activity on α-glucosidase, which was higher than that of Acarbose. However, at the concentration of 25mg/ml, among five extracts of F. Dibotryis Rhizoma, ethyl acetate extract showed strong inhibi- tory activity on or-amylase, higher than that of Acarbose. With the concentrations of five extracts increased, the inhibitory ratios also in- creased. Conclusion ：The ethyl acetate extract has significant antioxidant effect and shows the highest inhibitory activity on α-glucosidase and α-amylase among five extracts of F. Dibotryis Rhizoma.