title: Dietary conjugated linoleic acid reduces lipid peroxidation by increasing oxidative stability in rats.
abstract: The antioxidative effect of conjugated linoleic acid (CLA) was examined by determining lipid peroxidation and antioxidative enzyme activities. Male Sprague-Dawley rats were fed one of the experimental diets-normal diet, vitamin E-deficient control diet, 0.5% CLA vitamin E-deficient diet, or 1.5% CLA vitamin E-deficient diet for 5 wk. Hepatic thiobarbituric acid reactive substances (TBARS) were increased in the vitamin E-deficient control group, but they were was significantly lowered in the CLA groups. Similarly, hepatic glutathione peroxidase activity was increased in the vitamin E-deficient diet and reduced by CLA supplementation. In addition, CLA caused a significant decrease in superoxide dismutase activity while having no effect on catalase activity. Analyses of the fatty acid composition revealed that dietary CLA was incorporated into hepatic microsomal membrane dose-dependently. Compared to the vitamin E-deficient control, CLA resulted in significantly higher saturated and monounsaturated fatty acids (palmitic and oleic acids) while lowering levels of oxidation-susceptible polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acids) in both plasma and hepatic membrane. The concentrations of plasma cholesterol and triacylglycerol (TG) were lower in the 1.5% CLA group than in other groups. These results suggest that dietary CLA has antiatherosclerotic and antioxidant activity by increasing oxidative stability in plasma and hepatic membrane in the vitamin E-deficient rats.
authors.affiliation: Food Function Research Division, Korea Food Research Institute, Seongnam 463-746, Korea.
authors.forename: Hye-Kyeong
authors.initials: HK
authors.lastname: Kim
authors.forename: Sung-Ran
authors.initials: SR
authors.lastname: Kim
authors.forename: Ji-Yoon
authors.initials: JY
authors.lastname: Ahn
authors.forename: Il-Jin
authors.initials: IJ
authors.lastname: Cho
authors.forename: Chil-Suk
authors.initials: CS
authors.lastname: Yoon
authors.forename: Tae-Youl
authors.initials: TY
authors.lastname: Ha
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000097:blood; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D004032:Diet; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D005979:Glutathione Peroxidase / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000378:metabolism / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008055:Lipids / Q000097:blood; D008099:Liver / Q000737:chemistry / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000737:chemistry; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014810:Vitamin E / Q000008:administration & dosage
chemical_list: D000975:Antioxidants; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D044243:Linoleic Acids, Conjugated; D008055:Lipids; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase