title: Vitamin D is a membrane antioxidant. Ability to inhibit iron-dependent lipid peroxidation in liposomes compared to cholesterol, ergosterol and tamoxifen and relevance to anticancer action.
abstract: Vitamin D is a membrane antioxidant: thus Vitamin D3 (cholecalciferol) and its active metabolite 1,25-dihydroxycholecalciferol and also Vitamin D2 (ergocalciferol) and 7-dehydrocholesterol (pro-Vitamin D3) all inhibited iron-dependent liposomal lipid peroxidation. Cholecalciferol, 1,25-dihydroxycholecalciferol and ergocalciferol were all of similar effectiveness as inhibitors of lipid peroxidation but were less effective than 7-dehydrocholesterol; this was a better inhibitor of lipid peroxidation than cholesterol, though not ergosterol. The structural basis for the antioxidant ability of these Vitamin D compounds is considered in terms of their molecular relationship to cholesterol and ergosterol. Furthermore, the antioxidant ability of Vitamin D is compared to that of the anticancer drug tamoxifen and its 4-hydroxy metabolite (structural mimics of cholesterol) and discussed in relation to the anticancer action of this vitamin.
authors.affiliation: Pharmacology Group, King's College, University of London, UK.
authors.forename: H
authors.initials: H
authors.lastname: Wiseman
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D001923:Brain Chemistry; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002784:Cholesterol / Q000494:pharmacology; D004875:Ergosterol / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008081:Liposomes / Q000378:metabolism*; D013629:Tamoxifen / Q000494:pharmacology; D014807:Vitamin D / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D008081:Liposomes; D013629:Tamoxifen; D014807:Vitamin D; D002784:Cholesterol; D007501:Iron; D004875:Ergosterol