Objective: Iron overload is a serious, potentially fatal disorder characterized by the deposition of excess iron within tissues leading to functional impairment and reduced life expectancy. The present study was designed to evaluate the efficacy of melatonin in protecting rats against iron overload-induced toxicity.Methods: Twenty-four adult male rats were randomly divided into four groups: the control, iron overload group, melatonin group and iron overload+melatonin group. Rats received ferric hydroxide poly maltose at a dose of 50 mg/kg body weight (three doses per week) for four weeks through intra peritoneal injections and received the melatonin subcutaneously (10 mg/kg/day) for four weeks.Results: In iron overloaded rats, the iron status markers: serum, hepatic and renal tissues iron, Total Iron Binding Capacity (TIBC), transferrin and transferrin saturation percentage (TS %) were significantly increased, while a marked decrease in Unsaturated Iron Binding Capacity (UIBC) was demonstrated. The oxidative stress marker malondialdehyde (MDA) was significantly increased while a marked decrease in the catalase (CAT) and glutathione peroxidase (GPx) activities as well as in reduced glutathione (GSH) content accompanied with increased levels of metallothionein (MT) in hepatic and renal tissues were demonstrated. In addition, the liver and kidney functions were disturbed. Co-treatment with melatonin, significantly improved iron overload-induced alterations as indicated by the attenuation of the iron status disturbances, the reduction of the indices of liver and kidney functions and lipid peroxidation product and elevation of antioxidants and MT.Conclusion: The study showed the potential effect of melatonin against iron overload–induced toxicity through its chelating effect on iron, elevation of MT and improvement of antioxidant status.Â
