title: Prooxidant and antioxidant effects of Trolox on ferric ion-induced oxidation of erythrocyte membrane lipids.
abstract: The prooxidant and antioxidant actions of Trolox were examined in an in vitro system measuring ferric ion-induced oxidation of erythrocyte membrane lipids. Trolox was found to produce a concentration-dependent biphasic effect on the ferric ion-stimulated lipid peroxidation, with the mode of action being similar to those produced by reducing-agent antioxidants, such as ascorbic acid and reduced glutathione, and iron chelator, such as desferrioxamine. Phytic acid, a potent iron chelator, could suppress the prooxidant actions of Trolox and desferrioxamine, but not those of ascorbic acid and reduced glutathione. The ability of Trolox to stimulate ferric ion-catalyzed ascorbate oxidation, as similar to the action produced by ethylenediaminetetraacetic acid, indicates the presence of iron-chelating activity. The ensemble of results suggests the possible involvement of iron chelation in the prooxidant action of Trolox in ferric ion-stimulated lipid peroxidation reactions.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon.
authors.forename: K M
authors.initials: KM
authors.lastname: Ko
authors.forename: P K
authors.initials: PK
authors.lastname: Yick
authors.forename: M K
authors.initials: MK
authors.lastname: Poon
authors.forename: S P
authors.initials: SP
authors.lastname: Ip
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002839:Chromans / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism*; D006801:Humans; D007502:Iron Chelating Agents / Q000378:metabolism; D015227:Lipid Peroxidation; D008563:Membrane Lipids / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002839:Chromans; D005290:Ferric Compounds; D007502:Iron Chelating Agents; D008563:Membrane Lipids; D016877:Oxidants; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid