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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1995-7-6
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pubmed:abstractText |
The inhibition of low density lipoprotein (LDL) oxidation has been postulated as one mechanism by which antioxidants may prevent the development of atherosclerosis. Available data on the ability of beta-carotene to inhibit LDL oxidation are conflicting. We examined the role of in vivo and in vitro supplementation with beta-carotene on metal ion-dependent (cupric ions, Cu2+) and metal ion-independent (2,2'-azobis[2-amidinopropane]dihydrochloride, AAPH) oxidation of LDL as measured by the formation of conjugated dienes (absorbance at 234 nm). Sixteen subjects were supplemented with 50-100 mg of beta-carotene on alternate days for 3 weeks following a week-long loading dose of 100 mg/day. Plasma beta-carotene levels rose 5.5-fold, while LDL beta-carotene levels rose 8.5-fold. Oxidation of LDL by Cu2+ or AAPH was not significantly delayed after in vivo supplementation with beta-carotene compared with baseline. For AAPH, the lag phase (in minutes) was 75 +/- 8 at baseline and 83 +/- 14 after supplementation (P = 0.07). For Cu2+, the lag phase was 172 +/- 41 at baseline and decreased to 130 +/- 24 after supplementation (P < 0.01). Similarly, no protective effect against Cu(2+)-induced oxidation was observed when beta-carotene was added to LDL in vitro. Supplementation of plasma with beta-carotene in vitro prior to LDL isolation also did not enhance LDL's resistance to Cu(2+)- or AAPH-induced oxidation, despite a 5-fold increase in LDL beta-carotene levels over vehicle control.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0021-9150
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
20
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pubmed:volume |
112
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
187-95
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:7772078-Adult,
pubmed-meshheading:7772078-Carotenoids,
pubmed-meshheading:7772078-Female,
pubmed-meshheading:7772078-Humans,
pubmed-meshheading:7772078-Lipid Peroxidation,
pubmed-meshheading:7772078-Lipoproteins, LDL,
pubmed-meshheading:7772078-Male,
pubmed-meshheading:7772078-Middle Aged,
pubmed-meshheading:7772078-Oxidation-Reduction,
pubmed-meshheading:7772078-beta Carotene
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pubmed:year |
1995
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pubmed:articleTitle |
Supplementation with beta-carotene in vivo and in vitro does not inhibit low density lipoprotein oxidation.
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pubmed:affiliation |
Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
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pubmed:publicationType |
Journal Article,
Clinical Trial,
Randomized Controlled Trial,
Research Support, Non-U.S. Gov't
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