Abstract

To identify dietary phenolic compounds capable of improving vitamin E status, male Sprague-Dawleyrats were fed for 4 weeks either a basal diet ( control) with 2 g/kg cholesterol and an adequate content of vitamin E or the basal diet fortified with quercetin ( Q), (2)-epicatechin (EC), or (1)-catechin ( C) at concentrations of 2 g/kg. All three catechol derivatives substantially increased concentrations of alpha-tocopherol (alpha-T) in blood plasma and liver. To study potential mechanisms underlying the observed increase of alpha-T, the capacities of the Flavonoids to i) protect alpha-T from oxidation in LDL exposed to peroxyl radicals, ii) reduce alpha-tocopheroxyl radicals (alpha-T-.) in SDS micelles, and iii) inhibit the metabolism of tocopherols in HepG2 cells were determined. All flavonoids protected alpha-T from oxidation in human LDL ex vivo and dose-dependently reduced the concentrations of alpha-T-.. None of the test compounds affected vitamin E metabolism in the hepatocyte cultures. In conclusion, fortification of the diet of Sprague-Dawley rats with Q, EC, or C considerably improved their vitamin E status. The underlying mechanism does not appear to involve vitamin E metabolism but may involve direct quenching of free radicals or reduction of the alpha-T-. by the flavonoids

Published in

Journal of Lipid Research
2006, Volume: 47, number: 12, pages: 2718-2725
Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

SLU Authors

• Frank, Jan

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Lundh, Torbjörn

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

• Kamal-Eldin, Afaf

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science


Publication identifier

DOI: https://doi.org/10.1194/jlr.M600291-JLR200

Permanent link to this page (URI)

https://res.slu.se/id/publ/9776