Study of hypoglycemic, hypocholesterolemic and antioxidant activities of Iranian Mentha spicata leaves aqueous extract in diabetic rats

This study was conducted to evaluate the hypoglycemic, hypocholesterolemic and antioxidant properties of Mentha spicata (Labiateae) leaves aqueous extract (MSLA) in alloxan-induced diabetic rats. In this study, hyperglycemia was induced in male rats by intraperitoneal injection of alloxan monohydrate (150 mg/kg). The aqueous extract of M. spicata was orally administered at a dose of 300 mg/kg body weight to diabetic rats for 21 days and the effects were compared with glibenclamid (2 mg/kg). Fasting blood sugar (FBS), body weight, lipid profile and serum malondialdehyde (MDA) were monitored at 0, 7, 14 and 21 days after induction of diabetes. Total phenol contents (TP) and reducing power (RP) were also evaluated. TP and RP of aqueous extract were 2.763 ± 0.39 mg Gallic acid/gr and 0.026 ± 0.001 IC50 mg/ml, respectively. The LD50 of the extract was found to be ˃ 1500 mg/kg. The administration of M. spicata aqueous extract produced a significant reduction (P˂0.01) in FBS, total cholesterol, triglyceride, low density lipoprotein-cholesterol and MDA (101.83 ± 4.33, 95.66 ± 4.75, 89.83 ± 5.26, 26.20 ± 5.10 mg/dl and 1.53 ± 0.61 µmol/l, respectively) in diabetic rats. These effects were comparable with the effects of standard antidiabetic drug (glibenclamide). The results of the investigation indicated that M. spicata leaf aqueous extract possess hypoglycemic, hypocholesterolemic and antioxidant properties in diabetic rats. Therefore this study suggest a promising use it for treatment of diabetes.