Hypoglycemic activity of Salvia fruticosa Mill

Salvia fruticosa Mill. has a folk reputation in the eastern Mediterranean region as a hypoglycemic agent. In order to confirm this claim, a 10% infusion of its leaves was tested, at an oral dose of 0.250 g/kg b.w.t., on normoglycemic rabbits and in rabbits made hyperglycemic by alloxan administration. This oral dose caused a statistically significant reduction in blood glucose levels in alloxanhyperglycemic rabbits, but not in normoglycemic animals, only after repeated administrations of the infusion (once a day for 7 consecutive days). Instead, the hypoglycemic effect was evoked by single oral doses of infusion in both normoglycemic and alloxanhyperglycemic rabbits orally loaded with glucose. However, in these animals S. fruticosa infusion did not modify plasma insulin levels. Moreover, the hypoglycemic effect of the drug was not evoked in rabbits which received the glucose load intravenously. These data strongly suggest that S. fruticosa treatment produces hypoglycemia mainly by reducing intestinal absorption of glucose.