Alternation of hepatic antioxidant enzyme activities and lipid profile in streptozotocin-induced diabetic rats by supplementation of dandelion water extract

Background: Dandelion water extract (DWE), an herbal medication, may have an effect on the activity and mRNA expression of hepatic antioxidant enzymes and lipid profile in streptozotocin (STZ)-induced diabetic rats. Methods: Male Sprague-Dawley rats were divided into nondiabetic (control), diabetic, and diabetic-DWE-supplemented groups. Diabetes was induced by injecting streptozotocin (55 mg/kg BW, i.p.) in a citrate buffer. The extract was supplemented in 2.4 g of a DWE/kg diet. Results: The DWE supplement significantly decreased the serum glucose concentration in the diabetic rats. The hepatic superoxide dismutase and catalase activities significantly increased and the GSH-Px activity decreased in the diabetic rats, compared with the control group. When the DWE supplement was given to the diabetic rats, the antioxidant enzyme activity reverted to near-control values. However, there was no difference in the mRNA expression concentrations of these enzymes between the groups. With regard to the hepatic lipid peroxidation product, the malondialdehyde (MDA) content was significantly higher in the diabetic group than in the nondiabetic group. However, the DWE supplement lowered the hepatic MDA concentration in the diabetic-induced rats. The DWE supplement also lowered the total cholesterol and triglyceride concentrations in the serum and hepatic tissue, while increasing the serum HDL-cholesterol in the diabetic rats. Conclusions: A DWE supplement can improve the lipid metabolism and is beneficial in preventing diabetic complications from lipid peroxidation and free radicals in diabetic rats. (C) 2002 Elsevier Science B.V. All rights reserved.