Antioxidant and inhibition of α-glucosidase enzyme activity of extract and their fractions of Ashitaba (Angelica keiskei)

Diabetes Mellitus (DM) is a metabolic disorder characterized by hyperglycemic condition. Previous study was suggested that Ashitaba (Angelica keiskei) extract had the antidiabetic effect on diabetic rats. The active compound was identified as 4-hydroxyderricin. This research aimed to determine the antioxidant activity and inhibition potency on α-glucosidase enzymes of ethanol extract of ashoitaba and their fractions. Ashitaba (A. keiskei) herbs were collected from the local farmers and extracted by maceration. Fractination was performed by vaccum liquid chromatography using various solvents, while its mobile phase was hexane-chloroform (6: 4; 5: 5), hexane-ethyl acetate (9.5: 0.5; 9: 1; 8: 2), and ethanol. The result showed that the extract, non polar, semi polar and polar fractions had an inhibition activity on α-glucosidase enzyme with IC₅₀ values of 28.63, 18.45, 42.75 and 64.74 μg/mL, respectively. Based on the kinetics study, the activity of the samples showed a mixed type of inhibition. The antioxidant activity of extract was equal with vitamin E in which IC₅₀ values in sequence were 19.38 ± 0.99 and 19.54 ± 0.46 μg/mL. Meanwhile, IC₅₀ values of non polar, semi polar and polar fractions were 256.01 ± 3.79, 41.93 ± 0.43, and 116.7 ± 3.45 μg/mL, respectively. The semipolar fraction of Ashitaba was found with the strongest antioxidant activity compared to other fractions.