Contribution of Dietary Fats and Iron Ov e rload in Modulation of He patic Lipid Pe roxidation in Rats

Abstract

The effect of dietary lipids on hepatic lipid peroxidation and antioxidant status was studied in growing male albino rats (Sprague Dawley) during acute and chronic induction of hepatic iron overload. Three types of dietary fats were administrated (palm oil, butter fat and cotton seed oil) ad-libitum for 7 weeks. Acute iron overload was induced by subcutaneous injection of iron dextran at 50 mg/kg body weight on day 1, 3 and 5 before sacrificing. Chronic iron overload was produced by dietary supplementation with carbonyl iron (2.5 mg/g diet). Rats were fed the different experimental diets The biochemical and histological results revealed that rats with chronic iron overload showed reduced food intake and weight gain associated with marked increase in relative weight of organs and hepatic iron deposits especially in groups fed on butter fat. Hepatic malondialdehyde concentrations were significantly increased in iron-loaded liver as compared to_ controls and such increase was more apparent in the _ chronic iron loaded, cotton seed oil-fed groups. Thus, iron overload and cotton seed oil seem to have a synergistic effect on lipid peroxidation. Assessment of some antioxidant defence systems in the iron loaded rats disclosed a reduction in -erythrocyte Cu/Zn­ superoxide dismutase activity, plasma levels of a-tochopherol, selenium and manganese, with an increment of liver catalase and erythrocyte glucose-6-phosphate dehydrogenase activities. These changes were modulated by the type of ingested dietary fat. Our results showed also that experimental iron overload causes marked