Vomifoliol 9-O-α-arabinofuranosyl (1→6)-β-d-glucopyranoside from the leaves of Diospyros Kaki stimulates the glucose uptake in HepG2 and 3T3-L1 cells Original Research Article

A novel α-glucosidase inhibitor, vomifoliol 9-O-α-arabinofuranosyl (1→6)-β-d-glucopyranoside, was isolated for the first time from leaves of Diospyros Kaki and its bioactivity analyzed. This inhibitor exhibited strong anti-α-glucosidase activity with an IC50 value of 170.62 nM and stimulated a dose-dependent increase in the uptake of a fluorescent d-glucose analog, 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG), in HepG2 cells at a rate higher than that of insulin controls. It was also found to be associated with adipocyte differentiation and moderate increases in 2-NBDG uptake by 3T3-L1 cells. These findings suggest that vomifoliol 9-O-α-arabinofuranosyl (1→6)-β-d-glucopyranoside could augment peripheral glucose as an insulin-sensitizing agent against Type 2 diabetes mellitus.