In vitro and in vivo Inhibitory Activity of C-glycoside Flavonoid Extracts from Mung Bean Coat on Pancreatic Lipase and α-glucosidase.

ABSTRACT

Mung bean is a kind of legume commonly eaten by human. In the present study, a HPLC method for analyzing of two C-glycoside flavonoids, isovitexin and vitexin, in Mung bean was developed. Results showed that the flavonoids are mainly existed in Mung bean coat (MBC), while kernel contains very trace. The extraction of C-glycoside flavonoids from MBC was optimized. MBC extracts with isovitexin and vitexin contents of 29.0 ± 0.28% and 35.8 ± 0.19% were obtained with yield of 1.6 ± 0.21%. MBC extracts exhibited inhibitory activities on pancreatic lipase and α-glucosidase with IC50 values of 0.147 mg/ml and 0.226 mg/ml, respectively. The inhibitory kinetics revealed that MBC extracts showed mixed-type inhibition on these enzymes. Fluorescence quenching titration confirmed the binding of MBC extracts with the enzyme proteins. In vivo study revealed that pre-administration with MBC extracts significantly reduced the triglyceride absorption. Furthermore, it also improved postprandial hyperglycemia in rats through the inhibition of α-glucosidase.