Astaxanthin and peridinin inhibit oxidative damage in Fe(2+)-loaded liposomes: scavenging oxyradicals or changing membrane permeability?
Astaxanthin and peridinin, two typical carotenoids of marine microalgae, and lycopene were incorporated in phosphatidylcholine multilamellar liposomes and tested as inhibitors of lipid oxidation. Contrarily to peridinin results, astaxanthin strongly reduced lipid damage when the lipoperoxidation promoters-H(2)O(2), tert-butyl hydroperoxide (t-ButOOH) or ascorbate-and Fe(2+):EDTA were added simultaneously to the liposomes. In order to check if the antioxidant activity of carotenoids was also related to their effect on membrane permeability, the peroxidation processes were initiated by adding the promoters to Fe(2+)-loaded liposomes (encapsulated in the inner aqueous solution). Despite that the rigidifying effect of carotenoids in membranes was not directly measured here, peridinin probably has decreased membrane permeability to initiators (t-ButOOH > ascorbate > H(2)O(2)) since its incorporation limited oxidative damage on iron-liposomes. On the other hand, the antioxidant activity of astaxanthin in iron-containing vesicles might be derived from its known rigidifying effect and the inherent scavenging ability.
Barros
M P
MP
Department of Botany, Stockholm University, SE-10691 Stockholm, Sweden. mpbarros@botan.su.se
Pinto
E
E
Colepicolo
P
P
Pedersén
M
M
D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002338:Carotenoids / Q000008:administration & dosage / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002839:Chromans / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000008:administration & dosage / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008081:Liposomes; D008954:Models, Biological; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D024341:Xanthophylls; D019207:beta Carotene / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
D000975:Antioxidants; D002839:Chromans; D016166:Free Radical Scavengers; D008081:Liposomes; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D024341:Xanthophylls; D019207:beta Carotene; C016040:peridinin; D002338:Carotenoids; C005948:astaxanthine; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid