Benefits of zinc supplementation on the metabolic, redox and trace elements status in mild diabetic rats

Context: The function of zinc in the diabetes prevention, its management and complications are not clear. Aim: To determine the effect of zinc supplementation on the metabolic, redox and trace element status in mild diabetic Wistar rats. Methods: Thirty-two female Wistar rats equally distributed in four groups were studied: C: Control, CZn: Control-Zn-supplemented, D: Diabetic, DZn: Diabetic-Zn-supplemented. Diabetes was induced by streptozotocin (STZ-100 mg/kg-sc, second postnatal day). In adulthood, the corresponding groups were supplemented with zinc sulfate (ZnSO4x7H2O-100 mg/kg) for 14 days. Results: Zn supplementation in diabetic rats: -alleviated diabetes markers such as HbA1C, HOMA cell-β index, tolerance to glucose and insulin, polydipsia and polyuria; -decreased the Cu/Zn ratio levels in serum and tissues; -in liver and kidney improved excessive accumulation of Cu and increased the Zn concentrations, without causing toxicity; -increased the reduced glutathione (GSH) levels in liver and kidney and decreased the malonyldialdehyde (MDA) levels in liver, without changes in advanced oxidation protein products (AOPP); -evidenced negative correlation between tissue levels of Zn Vs MDA and AOPP. Conclusions: Zn supplementation favored glycemic control in rats with moderate diabetes, contributing to recovery of the metabolic, redox and trace elements status. Regulation of diabetes complications was associated with the antioxidant action of Zn. Nutritional supplementation with zinc may be suggested to prevent complications of diabetes in conditions of deficiency of this micronutrient.