Abstract
Effects of supplementation of n-3 and n-6 fatty acids on lipid peroxidation and DNA damage of rat tissues are shown. Rats were fed diet containing 5% safflower oil (S) rich in n-6 fatty acids or fish oil (F) rich in n-3 fatty acids for 6 weeks. Lipid peroxidation of erythrocyte membranes and other tissues as assessed by thiobarbituric acid-reactive substances and phospholipid hydroperoxides of both diet groups were not significantly different, whereas lipid peroidation of erythrocyte membranes of F diet group was higher than that of S diet group when they were oxidized under atmospheric conditions. Lipid peroxidaton and vitamin E content of hepatocyteas after intreperitoneal injection of Fe (III) of F diet group were higher and lower, respectively, than those of S diet group, whereas DNA damage of the cells of F diet group was lower than those of S diet group as assessed by 8-hydroxydeoxyguanine and comet assay. In vitro supercoiled DNA damage induced by various oxidants was inhibited by unoxidized polyunsaturated linoleic acid and low density lipoprotein, supporting that polyunsaturated fatty acids suppressed oxidative damage of DNA. The results indicate that supplementation of n-3 fatty acids reduces oxidative damage of DNA as compared with that of n-6 fatty acids.
