Antidiabetic activity of fruits and vegetables commonly consumed in Korea: Inhibitory potential against α-glucosidase and insulin-like action in vitro

Abstract

The α-glucosidase inhibition and insulin-like activity of 50 fruits and vegetables commonly consumed in Korea were analyzed using whole juice (WJ) samples and ethanol extracts (EE). Among the WJ samples, lotus root (30.4%) exhibited the highest α-glucosidase inhibitory activity, followed by Japanese apricot, sesame leaf, bracken, and spinach. Among the EE, 17 EE including potato (73.9%) were confirmed to have α-glucosidase inhibitory activity. The insulin-like activity of 22 types of fruits and vegetables with confirmed α-glucosidase inhibitory activity was tested by Oil Red O staining. WJ samples of lotus root and Japanese apricot and EE of cucumber, Japanese apricot, leek, spinach, and water dropwart induced 3T3-L1 cell differentiation into adipocytes in the absence of insulin. There was no significant difference in the adipocyte differentiation rate between these samples and those in which differentiation was induced by insulin. When 22 samples were mixed with insulin, 5 WJ samples and 12 EE showed enhanced 3T3-L1 differentiation. Our data demonstrate that certain fruits and vegetables commonly consumed in Korea have α-glucosidase inhibitory activity and insulin-like action. These fruits and vegetables could be used for blood glucose regulation in diabetic patients.