Effects of aqueous extract of turnip leaf (Brassica rapa) in alloxan-induced diabetic rats

Turnip leaf has been used in folk medicine of Iran for the treatment of diabetes. However,so far no scientific study has been done to support its use in traditional medicine. The present study was carried out to evaluate the possible hypoglycemic efficacy of aqueous extract of turnip leaf (AETL) in diabetic rats. Alloxan-induced diabetic rats were orally treated with AETL at doses of 200 and 400 mg/kg body weight (bw) per day for 28 days. In order to evaluate the anti-diabetic activity, fasting blood glucose concentrations were determined on the 1st, 14th and 29th days. Moreover,at the end of the study, plasma concentrations of total cholesterol, triglyceride (TG), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), aspartate amino transfarase (AST), and alanine amino transferase (ALT) were measured by the use of standard kits and auto-analyzer. Both doses of AETL significantly decreased (p<0.001) blood glucose and ALT levels in diabetic rats after 28 days of administration. AETL at both doses decreased (p<0.05) plasma total cholesterol and LDL-c in diabetic rats, but they significantly decreased (p<0.05) HDL-c and increased triglycerideand AST levels in a-dose dependent manner. The results showed that AETL has a dose- dependent decrease in the blood glucose in diabetic rats. However,we should not be unaware of adverse effects of AETL on lipid profiles and liver enzymes activity, especially decrease of HDL and increase of TG and AST.