Effects of the Autoxidized Oils on Lipid Metabolism and Drug Metabolizing Enzyme System in Rats

Abstract

Corn oil was autoxidized at room temperature by UV irradiation and four samples were obtained in the course of autoxidation.
Peroxide values of the four samples were 202 (SO₂₀₀), 399 (SO₄₀₀), 805 (SO₈₀₀), and 1117 (SO₁₁₀₀) respectively.
Each sample was administered to male Wistar rats and its effects on lipid metabolism and drug metabolizing enzyme system were investigated.
The results obtained were as follows:
(1) In the experiments at a single oral dose (4ml/kg) of autoxidized oils, aniline hydroxylase activity was significantly decreased at SO₄₀₀ administration, but was increased at SO₁₁₀₀. The content of liver triglyceride was decreased at SO₁₁₀₀. The activity of hepatic δ-aminolevulinic acid synthetase was increased both at SO₈₀₀ and at SO₁₁₀₀ administration.
(2) In the repeated oral dose of SO₈₀₀ or SO₁₁₀₀ (4ml/kg/day) for 10days or 7days respectively, aniline hydroxylase activity and the ratio of liver weight to body weight were increased at SO₁₁₀₀ administration. However, the activity of drug metabolizing enzymes, the contents of glycogen, microsomal protein, triglyceride, and cytochromes were not altered at SO₈₀₀ administration.
(3) In the experiments of a single intraperitoneal injection (4ml/kg) of SO₈₀₀, aminopyrine demethylase activity, the contents of microsomal protein and cytochrome P-450 were increased in 2hr after the injection, whereas the content of liver triglyceride was decreased approximately 50% in 6 or 12hr after the injection. On the other hand, the contents of liver triglyceride and serum cholesterol were increased in 24hr after the injection.