Oxidative changes associated with beta-carotene and alpha-tocopherol enrichment of human low-density lipoproteins.
J Am Coll Nutr
; 17(2): 171-9, 1998 Apr.
Article
em En
| MEDLINE
| ID: mdl-9550461
ABSTRACT
OBJECTIVE:
To determine what effects enrichment of human low-density lipoprotein (LDL) with combinations of alpha-tocopherol and beta-carotene would exert on LDL oxidation and attempt to define the nature of the effects.METHODS:
Human plasma was pooled and alpha-tocopherol and beta-carotene was added in a four-by-four design resulting in the enrichment of LDL with alpha-tocopherol and beta-carotene in varying concentrations. Enriched and control LDL was oxidized in Cu2+ mediated oxidation system and resistance of LDL to oxidation was determined by lag time, thiobarbituric acid reactive substances (TBARS) activity, and rate of oxidation.RESULTS:
Increasing LDL alpha-tocopherol concentration had a linear relationship with lag time and a negative correlation with rate of oxidation. LDL beta-carotene concentration was linearly correlated with the rate of LDL oxidation and beta-carotene loss, and exponentially related to TBARS concentration.CONCLUSIONS:
These results support earlier findings for the protective effect of a-tocopherol against LDL oxidation, and suggest that beta-carotene participates as a prooxidant in the oxidative degradation of LDL under these conditions. Since high levels of alpha-tocopherol did not mitigate the prooxidative effect of beta-carotene, these result indicate that increased LDL beta-carotene may cancel the protective qualities of alpha-tocopherol.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina E
/
Beta Caroteno
/
Lipoproteínas LDL
/
Antioxidantes
Tipo de estudo:
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Humans
Idioma:
En
Revista:
J Am Coll Nutr
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos