Antioxidant and α-Glucosidase inhibitory activity of formulated ethanol extract of red yeast rice and rice bran

Abstract

This research aimed to study the antioxidant and α-glucosidase inhibitory activity from the formulation of ethanol extract of red yeast rice and rice bran as well as to analyze total phenolic and flavonoid content. Red yeast rice and rice bran were extracted with ethanol through liquid-liquid extraction with n-hexane, dichloromethane, ethyl acetate, and water. Extract with the best antioxidant and α-glucosidase inhibitory activity was then formulated for antioxidant and α-glucosidase inhibition test. The highest antioxidant activity was found in red yeast rice and rice bran with the ratio of 1:1, having total phenolic and flavonoid content of 36.68 mg GAE/g and 11.10 mg QE/g respectively. The highest α-glucosidase inhibitory activity was found in formulation 1:0 of red yeast rice and rice bran, with IC50 value of 20.86 µg/mL. Meanwhile, other formulation of red yeast rice and rice bran (3:1, 1:1, 1:3) had IC50 value of 57.21, 34.52, 42.36μg/mL respectively.