DIETARY-FAT RICE IN MONO OR DI-UNSATURATED FATTY-ACIDS REDUCES LIPID OXIDATION IN HEPATIC TISSUE OF RABBITS

The effect of dietary vegetable oils (olive or sunflower oil) and alph a-tocopheryl acetate on fatty acid composition and lipid oxidation in rabbit liver has been evaluated. Animals receiving diets enriched in o live oil had higher levels of oleic acid in triglycerides and phosphol ipids (p<0.001) than animals receiving a fat source rich in polyunsatu rated fatty acids or diets not enriched with fat (NF). Concentration o f C20:5 (n-3), C22:5 (n-3) and C22:6 (n-3) in phospholipids was lower in animals receiving fat-enriched diets. The supplemental level of die tary alpha-tocopheryl acetate produced higher alpha-tocopherol concent ration in liver (p<0.009). Homogenates of liver from rabbits fed a bas al level of alpha-tocopheryl acetate were significantly more susceptib le to iron-induced lipid oxidation than those from rabbits fed diets s upplemented levels (p<0.002). Rabbits fed the NF diet had higher TBARS after 4 hours of incubation than liver homogenates from rabbits fed f at enriched diets (p<0.001). Differences in susceptibility to oxidatio n due to dietary administration of a fat source rich in (n-6) or (n-9) fatty acid could be related to variations in the concentration of (n- 3) fatty acids in phospholipids. (C) 1997 Elsevier Science Inc.