Tea extract inhibits intestinal absorption of glucose and sodium in rats.

The effect of tea extract on the intestinal absorption of glucose and sodium was studied in rats. Tea extract reduced the mucosal uptake of glucose and its portal plasma concentration, but was without any effect on its serosal transport. The mucosal uptake of sodium was similarly inhibited. The tea extract reduced also the in vitro activity of the Na(+)-K+ ATPase in an intestinal mucosal homogenate. These data are consistent with the hypothesis that an active ingredient in tea reduced sodium extrusion from the enterocytes by inhibiting the Na(+)-K+ pump, thus destroying the gradient needed for the mucosal transport of glucose.