Comparison of α-glucosidase inhibition by Cudrania tricuspidata according to harvesting time.

Cudrania tricuspidata (CT) is a type of add-value beneficial plant. The aim of the present study was to determine the components of CT that inhibit α-glucosidase activity. Roots, leaves and stems of the plants were obtained and several subgroups were created according to harvesting time. Root extracts exhibited a 77% velocity inhibition at a concentration of 300 μg/ml and an inhibitory constant of 41.6 μg/ml. The inhibitory percentage of the positive control at 1 mM was ∼67% of the enzymatic velocity with acarbose. According to the Michaelis-Menten equation, the type of inhibitory mechanism underlying the effects of the stem and root samples according to climate was competitive or non-competitive inhibition, suggesting that the extracts contain additional antidiabetic compounds produced during the growth period. Collectively, the results from our study suggested that stem and root extracts of CT serve as an antidiabetic biomaterial and contain a variety of antidiabetic compounds.