Phospholipid fatty acid and lipid peroxidation in liver microsomes from guinea pigs fed oil related to the toxic oil syndrome

Abstract

The potential effects of oil specimens both related and unrelated to cases of Toxic Oil Syndrome (TOS) on the phospholipid fatty acid composition, some antioxidant enzyme activities, and lipid peroxidation in guinea pig liver microsomes were investigated. For 4 weeks, animals were fed diets supplemented with either oil related to cases of TOS or control oil, previously heated or not. In all cases, the fat diet produced the incorporation of ∼7% of linoleic acid exclusively in the phosphatidylethanolamine (PE) of liver microsomes. A pronounced increase in lipid peroxidation products, measured as malondialdehyde (MDA) and 4-hydroxyalkenals, was detected in animals fed nonheated control oil. Heated oil diets produced significant increases in superoxide dismutase and glutathione peroxidase activities with concomitant decreases in the lipid peroxidation status. Heated oils also increased the oleic/stearic acid ratio in the phosphatidylserine plus phosphatidylinositol (PS+PI) fraction. This ratio was also increased in the same fraction from animals fed non heated case oil. The study shows that case oil produces a decrease in the lipid peroxidation products with minimal alterations in phospholipid fatty acid composition of liver microsomes, which is dependent rather on the composition of dietary fat than on toxic effects.