Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region

Abstract

The effect of an aqueous extract of Origanum vulgare (OV) leaves on blood glucose levels was investigated in normal and streptozotocin (STZ) diabetic rats. In normal rats, the blood glucose levels were slightly decreased 6 h after a single oral administration ( P<0.05) as well as 15 days after once daily repeated oral administration of aqueous OV extract ( P<0.05) (20 mg/kg). After a single dose or 15 daily doses, oral administration of the aqueous extract (20 mg/kg) produced a significant decrease on blood glucose levels in STZ diabetic rats ( P<0.001). In STZ rats, the blood glucose levels were normalised from the fourth day after daily repeated oral administration of aqueous OV extract (20 mg/kg) ( P<0.001). However, this effect was less pronounced 2 weeks after daily repeated oral administration of OV extract. In addition, no changes were observed in basal plasma insulin concentrations after treatment in either normal or STZ diabetic rats indicating that the aqueous OV extract acted without changing insulin secretion. We conclude that an aqueous extract of OV exhibits an anti-hyperglycaemic activity in STZ rats without affecting basal plasma insulin concentrations.