Inhibition of α-Amylase and α-Glucosidase of Anthocyanin Isolated from Berberis integerrima Bunge Fruits: A Model of Antidiabetic Compounds

Anthocyanins are components of the flavonoid group with different properties, such as antidiabetic properties. This study aimed to isolate anthocyanin from Berberis integerrima Bunge fruits and evaluate α-amylase and α-glucosidase inhibition by this mentioned anthocyanin. The anthocyanin of Berberis integerrima fruit was isolated using column chromatography, and the antidiabetic properties of the anthocyanin were determined by the levels of α-amylase and α-glucosidase inhibition. Km and Vmax were also evaluated using the GraphPad Prism 7. The results of this study showed that the anthocyanin content of the fruit extract was 14.36 ± 0.33 mg/g, and following purification, this amount increased to 34.51 ± 0.42 mg/g. The highest of α-glucosidase inhibition was observed in the purified anthocyanin with IC(50) = 0.71 ± 0.085 mg/ml, compared to acarbose as the baseline with IC(50) = 8.8 ± 0.14 mg/ml, p < 0.0001. Purified anthocyanin of the mentioned fruit with IC(50) = 1.14 ± 0.003 mg/ml had the greatest α-amylase inhibition, which was similar to acarbose as the standard with IC(50) = 1 ± 0.085 mg/ml, p < 0.05. The inhibition of α-glucosidase and α-amylase by purified anthocyanin showed uncompetitive inhibition, and the enzyme inhibition by unpurified anthocyanin showed mixed inhibition. The obtained findings showed that Berberis integerrima fruit can be mentioned as a source of anthocyanin with antidiabetic properties.