title: In vitro antioxidant activity of 2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC), a vitamin E metabolite.
abstract: 2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) has been identified as a major water-soluble metabolite of vitamin E, which circulates in the blood and is excreted with the urine. The aim of this study was to assess the antioxidant activity of alpha-CEHC using several methods with different prooxidant challenges. In the Oxygen Radical Absorbance Capacity assay, a fluorescent protein acts as a marker for oxidative damage induced by peroxyl radicals. In the Trolox Equivalent Antioxidant Capacity (TEAC) assay, a stable free radical, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS.+) is reduced directly by antioxidants. Scavenging properties vs. reactive nitrogen species were studied measuring the effects on tyrosine nitration after reaction with peroxynitrite. Trolox, alpha-tocopherol, ascorbic acid, and (-)-epicatechin were simultaneously tested in order to compare their antioxidant activities. In all mentioned systems, alpha-CEHC exhibited antioxidant properties similar to those of Trolox. We conclude that alpha-CEHC is a molecule with good antioxidant activity, having the advantage over Trolox of being a naturally occurring compound. These properties might be useful for research or industrial purposes.
authors.affiliation: Institut für Physiologische Chemie I, Heinrich-Heine Universität Düsseldorf, Germany.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Betancor-Fernandez
authors.forename: Helmut
authors.initials: H
authors.lastname: Sies
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Stahl
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Polidori
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000378:metabolism; D002839:Chromans / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D008956:Models, Chemical; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism; D011422:Propionates / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D002839:Chromans; D011422:Propionates; D014810:Vitamin E; D030421:Peroxynitrous Acid; C084852:2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman; D014443:Tyrosine; D009584:Nitrogen; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D010100:Oxygen