RESUMO
Intestinal glucose uptake is mainly performed by its specific transporters, SGLT1 and GLUTs expressed in the intestinal epithelial cells. By using Caco-2 cells and 2-NBDG, we observed that intestinal glucose uptake was markedly inhibited by pomegranate (Punica granatum L, PG) among 200 screened edible Korean plants. The effects of the PG extract on Na(+)-dependent glucose uptake were further evaluated using brush border membrane vesicles (BBMV) obtained from the mouse small intestine. PG inhibited Na(+)-dependent glucose uptake with the IC(50) value of 424 µg/ml. The SGLT1 protein expression was dose dependently down regulated with PG treatment in Caco-2 cells. We next assessed the antihyperglycemic effect of PG in streptozotocin (STZ)-induced diabetic mice. Administration of PG (800 mg/kg) to STZ mice for four weeks improved postprandial glucose regulation. Furthermore, elevated Na(+)-dependent glucose uptake by BBMV isolated from STZ mice was normalized by PG treratment. These results suggest that PG could play a role in controlling the dietary glucose absorption at the intestinal tract by decreasing SGLT1 expression, and may contribute to blood glucose homeostasis in the diabetic condition.