Biological markers of oxidative stress induced by ethanol and iron overload in rat

Studies on rats treated for 15 months with ethanol (10%, w/v, solution in drinking water) revealed that the stimulation of hepatic cytochrome P-450 monooxygenases activity was accompanied by enhanced microsomal malondialdehyde formation, a lipid peroxidation index and a decreased level of the antioxidant, alpha-tocopherol. The other components of the prooxidant/antioxidant system, diene conjugates and catalase, glutathione peroxidase and superoxide dismutase activities were unaffected. Oxidative stress in blood was shown by a significant decrease in the alpha-tocopherol level whereas lipid peroxidation and antioxidant enzyme activity remained unchanged. The prooxidative effect of ethanol was catalytically promoted by an iron overload (Fe-saccharate, 100 mg Fe3+/kg body wt. intraperitoneally, 2, 5 and 7 day before test) to simulate the effect of alcoholic hemochromatosis. Thus, the level of malondialdehyde and alpha-tocopherol in the serum may be recommended as biological markers of ethanol-provoked oxidative stress, which is especially useful in the evaluation of the combined effect of ethanol and other chemicals that affect the redistribution of active iron complexes.