title: Lack of effect of oral supplementation with antioxidants on cholesterol oxidation product concentration of human plasma, as revealed by an improved gas chromatography method.
abstract: A gas chromatographic method was successfully applied to determine cholesterol oxidation products (COPs) in human plasma. The linearity, precision, recovery and sensitivity of the method were determined. Oral supplementation with a combination of vitamin E (800 IU), C (1 g) and beta-carotene (24 mg), given for 21 days to 21 patients, did not significantly decrease plasma COP content. No correlations (n = 26) were found between initial plasma COP content and the following parameters: age, body mass index, plasma content of alpha-tocopherol, cholesterol, high-density lipoprotein cholesterol and triglycerides, and fat, natural antioxidant and oxidized lipid intake. Differences in plasma COP content between type 2 diabetic (n = 6) and nondiabetic (n = 20) patients were not statistically significant. The results from this study lead us to hypothesize that the nonenzymatic oxidation of cholesterol in plasma is negligible compared to COPs originating from the diet. This article also includes a comprehensive review of the drawbacks of the analytical methods of COP determination in plasma and serum.
authors.affiliation: Nutrition and Food Science Unit--CeRTA, Faculty of Pharmacy, University of Barcelona, Av. Joan XXIII s/n, 08028, Barcelona, Spain. fguardiola@ub.edu
authors.forename: Francesc
authors.initials: F
authors.lastname: Guardiola
authors.forename: Alba
authors.initials: A
authors.lastname: Tres
authors.forename: Rafael
authors.initials: R
authors.lastname: Codony
authors.forename: Paul B
authors.initials: PB
authors.lastname: Addis
authors.forename: Scott D
authors.initials: SD
authors.lastname: Bergmann
authors.forename: James H
authors.initials: JH
authors.lastname: Zavoral
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood*; D002849:Chromatography, Gas / Q000379:methods*; D003920:Diabetes Mellitus / Q000097:blood; D019587:Dietary Supplements; D006801:Humans; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction / Q000187:drug effects; D012680:Sensitivity and Specificity
chemical_list: D000975:Antioxidants; D002784:Cholesterol