Effects of an ethanolic extract of Berberis vulgaris fruits on hyperglycemia and related gene expression in streptozotocin-induced diabetic rats

Abstract

Finding a treatment for diabetes that does not have side effects has remained elusive. Among natural agents, much attention has been focused on phenolic compounds. For both their medicinal and nutritional value, barberry plants are of particular interest. Berberis vulgaris is known for its medicinal benefits in Iranian traditional medicine. In this study, we investigated the biological activities of B.vulgaris in a rodent model of experimentally induced diabetes. The fasting blood glucose (FBG), insulin, malondialdehyde (MDA), and total antioxidant levels were measured in experimental groups of rats, including normoglycemic control, diabetic control, and diabetics treated with B.vulgaris, and the gene expression of the stress proteins HSF-1, HSP27, and HSP70 as well as the enzymes glucokinase (GK) and glucose 6-phosphatase (G6P) were assayed by real-time PCR. The application of the alcoholic extract of B.vulgaris (25 and 100 mg/kg body mass) significantly increased the total antioxidant levels, decreased MDA and FBG levels, and also increased mRNA level of GK compared with the diabetic control group (P ≤0.05). Our results also showed a reduction in HSP70 gene expression and a significant decrease in G6P gene expression in a dose-dependent manner (P ≤ 0.05). The effect of alcoholic extract of barberry at a higher dose (100 mg/kg) was similar to glibenclamide. B.vulgaris extract is beneficial in ameliorating oxidative stress and may be useful in the treatment of diabetes. The therapeutic potential of B.vulgaris may be through the modification of the gene expression of key enzymes or stress proteins and requires further investigation.