羊栖菜提取物的体外抗氧化活性及降低小鼠餐后血糖作用

为了研究羊栖菜不同溶剂萃取物的抗氧化及降低餐后血糖活性,用石油醚、二氯甲烷、乙酸乙酯、正丁醇依次萃取羊栖菜乙醇提取物得到各萃取物,测其总多酚、黄酮含量;运用DPPH·、ABTS·、FRAP三种方法评价抗氧化活性,对-硝基苯基-α-D吡喃葡萄糖苷(PNPG)法及DNS法测定其对α-葡萄糖苷酶、α-淀粉酶抑制率,小鼠糖耐量实验评价其降低餐后血糖作用。结果表明乙酸乙酯萃取物的总多酚和黄酮含量最高,分别是34.47 mg/g和5.77 mg/g,其抗氧化活性仅在DPPH·试验中略低于正丁醇萃取物,当浓度为1.6 mg/mL时,乙酸乙酯萃取物的抗氧化活性分别是90.17%(DPPH·)、0.35 mmol/mg(ABTS·)和0.72 mmol/mg(FRAP);在α-葡萄糖苷酶抑制实验中,石油醚、二氯甲烷、乙酸乙酯萃取物的IC50值分别是0.54、0.29、0.27 mg/mL;前三种萃取物均能明显降低餐后血糖。本研究表明乙酸乙酯萃取物具有作为膳食补充剂或糖尿病治疗药物的潜力,为羊栖菜的深度开发利用提供了理论依据。

In vitro Antioxidant Activity and Reduction of Postprandial Blood Glucose by the Extracts from Sargassum fusiforme

To study the antioxidant and lower postprandial blood glucose activities by different solvents extracts from Sargassum fusiform,the ethanol extract of Sargassum fusiforme was fractionated by different organic solvents(Petroleum ether,dichloromethane,ethyl acetate,butyl alcohol,PE,DCM,EAC,NBA).The contents of phenols and flavonoids were measured,then the DPPH·,ABTS·,and FRAP methods were used to evaluate the antioxidant activity,the p-nitrophenyl-α-D glucopyranoside(PNPG)and DNS methods were used to determine the inhibition rate ofα-glucosidase andα-amylase.Finally,glucose tolerance was measured to evaluate the effect on the postprandial blood glucose.Result showed that EAC extract exhibited the highest total phenols and flavonoids contents,which were 34.47 mg/g and 5.77 mg/g,respectively,and its antioxidant activity was only slightly lower than that of NBA extract in DPPH test,when the concentration was 1.6 mg/mL,the antioxidant activities of EAC extract were 90.17%(DPPH·),0.35 mmol/mg(ABTS·)and 0.72 mmol/mg(FRAP);in theα-glucosidase inhibition experiment,the IC50 of PE,DCM,EAC extracts were 0.54,0.29,and 0.27 mg/mL,respectively.The first three extracts can significantly reduce postprandial blood glucose.This study shows that EAC extract has the potential to be used as a dietary supplement or anti-diabetic medicine,providing a theoretical basis for the development and utilization of Sargassum fusiforme.