BETA-CAROTENE ALTERS VITAMIN-E PROTECTION AGAINST HEME PROTEIN OXIDATION AND LIPID-PEROXIDATION IN CHICKEN LIVER SLICES

This study investigated the interaction between dietary beta-carotene and vitamin E in protecting against heme protein oxidation and lipid peroxidation initiated by incubation of liver slices with ferrous sulfate. Male leghorn chicks were fed a basal diet deficient in beta-carotene and vitamin E for 3 weeks. Beta-carotene (0, 30, and 100 mg/kg) and vitamin E (0, 50 mg/kg) were added to the diet using a 3 X 2 factorial arrangement of treatments. Analysis of variance showed the following significant effects. Vitamin E protected against both heme protein oxidation and lipid peroxidation as measured by thiobarbituric acid reactive substances (P less than or equal to 0.001). Liver slices from vitamin E adequate chicks had less hemichrome and produced fewer thiobarbituric acid reactive substances than liver slices from vitamin E-deficient chicks. Addition of p-carotene to the diets did not protect chicks significantly against either hemichrome formation or the production of thiobarbituric acid reactive substances (P less than or equal to 0.001). Supplementation of the vitamin E-adequate diet with 100 mg beta-carotene/kg diet resulted in substantially lower retention of hepatic vitamin E (P less than or equal to 0.001).