Document Detail


beta-Carotene: an unusual type of lipid antioxidant.
MedLine Citation:
PMID:  6710156     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mechanism of lipid peroxidation and the manner in which antioxidants function is reviewed. beta-Carotene is a purported anticancer agent, which is believed by some to have antioxidant action of a radical-trapping type. However, definitive experimental support for such action has been lacking. New experiments in vitro show that beta-carotene belongs to a previously unknown class of biological antioxidants. Specifically, it exhibits good radical-trapping antioxidant behavior only at partial pressures of oxygen significantly less than 150 torr, the pressure of oxygen in normal air. Such low oxygen partial pressures are found in most tissues under physiological conditions. At higher oxygen pressures, beta-carotene loses its antioxidant activity and shows an autocatalytic, prooxidant effect, particularly at relatively high concentrations. Similar oxygen-pressure-dependent behavior may be shown by other compounds containing many conjugated double bonds.
Authors:
G W Burton; K U Ingold
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Science (New York, N.Y.)     Volume:  224     ISSN:  0036-8075     ISO Abbreviation:  Science     Publication Date:  1984 May 
Date Detail:
Created Date:  1984-05-24     Completed Date:  1984-05-24     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0404511     Medline TA:  Science     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  569-73     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Antioxidants / metabolism*
Carotenoids / metabolism*
Chemical Phenomena
Chemistry
Free Radicals
Humans
Linoleic Acids / metabolism
Lipid Metabolism*
Oxidation-Reduction
Oxygen / metabolism
Partial Pressure
Peroxides / metabolism
Tetrahydronaphthalenes / metabolism
beta Carotene
Chemical
Reg. No./Substance:
0/Antioxidants; 0/Free Radicals; 0/Linoleic Acids; 0/Peroxides; 0/Tetrahydronaphthalenes; 112-63-0/methyl linoleate; 36-88-4/Carotenoids; 7235-40-7/beta Carotene; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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