Background and purpose: Diabetes mellitus is a common metabolic disease, currently affecting more than 280 million people worldwide. Centaurea cyanus known as cornflower has antioxidant properties and is used in traditional medicine in lowering blood sugar. This study aimed at determining the biochemical and histopathological changes in serum and the kidneys of diabetic rats treated with hydroalcoholic extract of Centaurea cyanus.

Materials and methods: In this study, 60 male Wistar rats were divided into five groups (n= 12 per group). Diabetes was induced by alloxan. The diabetic rats were treated for 8 weeks with hydro alcoholic extract of C. cyanus at two concentrations (400 and 800 mg/kg). Finally, the animals were anesthetized and the serum levels of glucose, creatinine and urea and kidney tissue catalase level were measured. The kidney tissue slides were histopathologically examined.

Results: Histopathological examination showed that similar to the control group, there were no significant changes in histolological features of the group receiving 800 mg/kg extract of the C. cyanus. In the group treated with 400 mg/kg of the extract there were mild tubular changes. Biochemical examination showed higher levels of creatinine in the group receiving the extract at 800 mg/kg. The level of urea in the group receiving the extract at 400 mg/kg, was significantly higher compared to that of the control group. (P<0.05).

Conclusion: Consumption of Centaurea cyanus extract at 800 mg/kg could prevent kidney tissue injuries in diabetic rats, but further investigations are required before its use in treatment of patients with diabetes.