초록
The effect of ${\alpha}$-tocopherol and ${\beta}$-carotene supplementation on reducing the oxidative damag in the liver of rats were studied. Forth-five male Sprague Dawley aged 4 weeks were randomly assigned to 9 groups of five for the 12 weeks of the study. Nine groups, sardine oil, sardine oil＋Vt E, sardine oil＋${\beta}$-carotene, soybean oil, soybean oil＋Vt E, soybean oil＋${\beta}$-carotene, lard, lard＋Vt E, lard＋${\beta}$-carotene group, were prepared. Sardine oil, soybean oil, or lard was used for dietary fat and 200% of ${\alpha}$ -tocopherol or 150% of ${\beta}$-carotene was supplemented to each diet. Each diet supplied 65% of total energy as carbohydrate, 15% as protein, and 20% as lipid. The MDA value and protein carbonyl contents of sardine oil group were significantly different(p<0.05) to those of other fat groups indicating that the most severe lipid oxidation occurred in the group fed diet containing highly polyunsaturated fatty acid. When ${\alpha}$-tocopherol or ${\beta}$ -carotene was supplemented to the sardine oil diet, MDA value(-35%, -15%, respectively) and protein carbonyl content(-44%, -32%, respectively) decreased significantly(p<0.05). Cu, Zn-superoxide dismutase(SOD) and catalase activities of three different sardine oil groups with or without antioxidants were lower than those of soybean oil or lard group. The reducing effect of ${\alpha}$-tocopherol on oxidative damage in sardine oil group supplemented with ${\alpha}$-tocopherol was noticeable(p<0.05). However the adverse effect of ${\beta}$-carotene was observed. SOD and catalase activities of ${\beta}$-carotene supplemented groups were that the lowest among the same fat groups, but the differences were not statistically significant. The possible cause of decreased enzyme activity seemed to be related to the vitamin A(Vt A) toxicity in the liver where retinol converted from dietary ${\beta}$-carotene in the intestinal mucosa was stored.