Beneficial effects of a standardized Hypericum perforatum extract in rats with experimentally induced hyperglycemia

The main aim of this study was to test the therapeutic potential of a standardized Hypericum perforatum extract in treating metabolic disturbances commonly associated with type-2 diabetes mellitus. Daily oral administration of the Hypericum perforatum extract (100, 200, and 300 mg/kg/day) for 14 consecutive days counteracted in a dose-dependent manner the alterations in blood glucose levels and lipid profile as well as liver glycogen content and body weight changes observed in a rat mode of nicotinamide-streptozotocininduced diabetes. In general, effects of the highest dose of the extract in this model were quite similar, but not identical, to those of a 10 mg/kg/day dose of glibenclamide. The effects of single oral doses of the extract in a rat oral glucose tolerance test conducted in fasted animals were also analogous to those of an antidiabetic drug therapeutic use. These observations not only further expand the therapeutic potentials of Hypericum extracts but also indicate that stimulation of insulin release could be involved in their modes of actions. The importance of an extract with diverse, therapeutically interesting pharmacological properties is also briefly discussed.