Improvement of superoxide dismutase and catalase in streptozotocin–nicotinamide-induced type 2-diabetes in mice by berberine and glibenclamide

Abstract

Context: Diabetes mellitus (DM) type 2 is a chronic disease characterized by hyperglycemia and insulin resistance. Oxidative stress participates in development and progression of DM, in which changes of superoxide dismutase (SOD) and catalase (CAT) were noted in DM mice. Berberine has been widely used as an alternative medicine and proved to be effective for the treatment of DM and dyslipidemia.Objective: Impacts of berberine on transcriptional regulation of SOD and CAT and their enzyme activities, including the level of malondialdehyde (MDA) formation, were examined in the DM type 2-induced mice to clarify its antioxidation potential, compared with a common hypoglycemic drug, glibenclamide.Materials and methods: Noninsulin-dependent diabetes was induced in mice by a single intraperitoneal streptozotocin–nicotinamide injection. Diabetic mice were treated daily with glibenclamide (10 mg/kg/d) and/or berberine (100 mg/kg/d) for 2 weeks. The fasting blood glucose and the MDA levels in the mouse liver, brain and kidneys were monitored using Glucometer® (Accu-Check® Advantage II Performa kits, Roche Diagnostics, Germany) and thiobarbituric acid substance assay, respectively. The expression of SOD and CAT mRNA were determined in the mouse liver and the activities of SOD and CAT enzymes were determined in mouse liver, brain and kidneys, respectively.Results: Berberine exhibited similar hypoglycemic potential as glibenclamide to lower area under the curve of the fasting blood glucose. In DM type 2 mice, berberine increased the hepatic CuZn-SOD mRNA expression and the kidney SOD and CAT activities to normal levels. Moreover, DM-induced lipid peroxidation by increasing of MDA levels in both the liver and brain and lipid peroxidation status was restored by berberine.Conclusion: Berberine possessed hypoglycemic properties and strong potential to improve the oxidant–antioxidant balance, though the combination treatment of berberine and glibenclamide did not show additional benefit over the treatment with berberine alone.