Background: Bis(alpha-furancarboxylato)oxovanadium(IV) (BFOV), a new orally active anti-diabetic vanadium complex with organic agent, has been synthesized and characterized. The current study examined the stability in aqueous solution and effects of the complex on carbohydrate and lipid metabolism in non-diabetic and streptozotocin-induced diabetic rats. Methods: Diabetic rats were induced by a single dose injection of streptozotocin (STZ, 50 mg/kg body weight. i.p.). The rats were randomly divided into non-diabetic (control, CON), diabetic (DM) and BFOV (0.2 mmol/kg body weight)-treated, diabetic-BFOV (0.1, 0.2 and 0.4 mmol/kg body weight) groups. All substances were given intragastrically to non-diabetic and STZ-induced diabetic rats for 4 weeks. Blood glucose concentration was monitored during administration and, at the end of experiment glycosylated hemoglobin, serum insulin, lipid concentrations and glycogen content were observed. Results: Administration of BFOV to STZ-diabetic rats dose-dependently reduced blood glucose concentration when compared to diabetic rats (P < 0.01), but it did not influence blood glucose in non-diabetic rats. Serum insulin concentrations were not increased in the BFOV-treated diabetic groups and, in contrast, significantly lowered in the 0.2 mmol/kg body weight BFOV-treated non-diabetic group at the end of experiment. Moreover, BFOV markedly reduced glycosylated hemoglobin concentration and improved dyslipidemia in STZ-diabetic rats, in a dose-dependent manner (P < 0.05, P < 0.01), but had no significant effect on non-diabetic rats. Conclusion: The organic vanadium complex was found to effectively attenuate diabetic alterations in STZ-diabetic rats. (c) 2006 Elsevier B.V All rights reserved.