title: Differential effects of carotenoids on lipid peroxidation due to membrane interactions: X-ray diffraction analysis.
abstract: The biological benefits of certain carotenoids may be due to their potent antioxidant properties attributed to specific physico-chemical interactions with membranes. To test this hypothesis, we measured the effects of various carotenoids on rates of lipid peroxidation and correlated these findings with their membrane interactions, as determined by small angle X-ray diffraction approaches. The effects of the homochiral carotenoids (astaxanthin, zeaxanthin, lutein, beta-carotene, lycopene) on lipid hydroperoxide (LOOH) generation were evaluated in membranes enriched with polyunsaturated fatty acids. Apolar carotenoids, such as lycopene and beta-carotene, disordered the membrane bilayer and showed a potent pro-oxidant effect (>85% increase in LOOH levels) while astaxanthin preserved membrane structure and exhibited significant antioxidant activity (40% decrease in LOOH levels). These findings indicate distinct effects of carotenoids on lipid peroxidation due to membrane structure changes. These contrasting effects of carotenoids on lipid peroxidation may explain differences in their biological activity.
authors.affiliation: Elucida Research, 100 Cummings Center, Suite 135L, P.O. Box 7100, Beverly, MA 01915-0091, USA. hmcnulty@elucidaresearch.com
authors.forename: Hyesun P
authors.initials: HP
authors.lastname: McNulty
authors.forename: Jungsoo
authors.initials: J
authors.lastname: Byun
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Lockwood
authors.forename: Robert F
authors.initials: RF
authors.lastname: Jacob
authors.forename: R Preston
authors.initials: RP
authors.lastname: Mason
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002338:Carotenoids / Q000737:chemistry / Q000494:pharmacology*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D002784:Cholesterol / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008081:Liposomes; D014975:Lutein / Q000494:pharmacology; D000077276:Lycopene; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D008968:Molecular Conformation; D015394:Molecular Structure; D014961:X-Ray Diffraction; D024341:Xanthophylls / Q000494:pharmacology; D065146:Zeaxanthins; D019207:beta Carotene / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005231:Fatty Acids, Unsaturated; D008081:Liposomes; D008563:Membrane Lipids; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; C005948:astaxanthine; D002784:Cholesterol; D000077276:Lycopene; D014975:Lutein