Hawthorn evokes a potent anti-hyperglycemic capacity in streptozotocin-induced diabetic rats.

The hypoglycaemic effect of an aqueous extract of hawthorn leaves (Crataegus oxyacantha) was investigated in normal and streptozotocin (STZ) diabetic rats. After a single dose or 9 daily doses, oral administration of the aqueous extract produced a significant and dose-dependent decrease on blood glucose levels in STZ diabetic rats (P < 0.001), but had no effect on blood glucose levels in normal rats. No changes were observed in basal plasma insulin concentrations after treatment in normal or STZ diabetic rats. In addition, the acute toxicity study of the extract was investigated in mice. The results obtained showed that the aqueous extract had a high LD50 value (13.5 g/kg) in mice. We conclude that an aqueous extract of hawthorn leaves exhibits a potent anti-hyperglycemic activity in STZ rats, but not in normal rats, without affecting basal plasma insulin concentrations.