Oxidative damage plays a key role in alcohol-mediated liver alterations. Selenium, a potent antioxidant, is decreased in alcoholics. This study was conducted to analyse if the supplementation with selenium may alter liver changes in a murine model fed ethanol and/or a 2 % protein-containing diet, following the Lieber-DeCarli design. Adult male Sprague Dawley rats were divided into eight groups which received the Lieber-DeCarli control diet; an isocaloric, 36 % ethanol-containing diet; an isocaloric, 2 % protein-containing diet; and an isocaloric diet containing 2 % protein and 36 % ethanol diet; and other similar four groups to which selenomethionine (1 mg/kg body weight) was added. After sacrifice (5 weeks later), liver fat amount and hepatocyte areas of pericentral and periportal cells were measured, and liver and serum selenium, activity of liver glutathione peroxidase (GPX), and liver malondialdehyde were determined. Ethanol-fed rats showed increased hepatocyte areas and fat accumulation especially when ethanol was added to a 2 % protein diet. Selenium caused a decrease in hepatocyte ballooning and liver fat amount, but an increase in GPX activity, and a marked increase in serum and liver selenium. The present study demonstrates that selenium, added to the diet of rats in the form of seleniomethionine, prevents the appearance of early signs of ethanol-mediated liver injury under the conditions of the Lieber-DeCarli experimental design.

Selenium is a main component of glutathione peroxidase (GPX), a key antioxidant enzyme. Other elements, such as zinc, copper, manganese and iron, are also involved in the pathogenesis of oxidative damage as well as in other important metabolic pathways. The effects of selenium supplementation on the metabolism of these elements have yield controversial results .The aim of this study is to analyse the effects of selenium supplementation on liver, muscle and urinary excretion of zinc, copper, iron and manganese in a situation of oxidative stress, such as protein deficiency. The experimental design included four groups of adult male Sprague-Dawley rats, which received the Lieber-DeCarli control diet, an isocaloric 2 % protein-containing diet and another similar two groups to which selenomethionine (6 mg/l liquid diet) was added. After sacrifice (5 weeks later), muscle, liver and serum selenium were determined, as well as muscle, liver and urinary zinc, copper, manganese and iron and liver GPX activity and liver malondialdehyde. Selenium addition led to decreased liver copper, increased muscle copper, increased copper excretion and increased liver iron, whereas zinc and manganese parameters were essentially unaltered. Muscle, liver and serum selenium were all significantly correlated with liver GPX activity.