LDL susceptibility to copper-induced oxidation after administration of a single dose of free or esterified beta-cryptoxanthin.
BACKGROUND
The oxidative modification of LDL is believed to be an initial step in atherosclerosis. Thus, antioxidative substances such as carotenoids may have a role in the prevention of coronary heart disease. We examined the susceptibility of LDL to Cu2+ oxidation in young adults before and after a single dose of beta-cryptoxanthin.


METHODS
1.3 mg of beta-cryptoxanthin was administered to 12 apparently healthy young volunteers. Six of the volunteers received esters, the other six free beta-cryptoxanthin. The plasma concentration of beta-cryptoxanthin and the susceptibility of LDL to copper-induced oxidation ex vivo in terms of the duration of lag time were measured before and 12 h after beta-cryptoxanthin ingestion.


RESULTS
A single dose of beta-cryptoxanthin significantly increased the mean plasma beta-cryptoxanthin concentration and the mean cholesterol adjusted beta-cryptoxanthin concentration by 117 and 133%, respectively. No effect on the length of lag time was assessed. However, in LDL isolated from plasma 12 h after beta-cryptoxanthin administration the lengths of lag time correlated significantly with the plasma beta-cryptoxanthin concentration and with the cholesterol adjusted beta-cryptoxanthin levels. The lag time did not differ significantly between volunteers who received esters and those who received the same dosage as free beta-cryptoxanthin. At both measuring points, smokers, male volunteers and women using oral contraceptives tended to exhibit lower beta-cryptoxanthin concentrations and lower cholesterol adjusted beta-cryptoxanthin concentrations as well as increased LDL oxidizability compared to nonsmokers and women not using oral contraceptives.


CONCLUSIONS
A single dose of beta-cryptoxanthin does not enhance the duration of LDL lag time ex vivo in healthy young subjects.
Wolters
Maike
M
Institute of Food Science, University of Hannover, Hannover, Germany. maike.wolters@lw.uni-hannover.de
Hahn
Andreas
A
D000328:Adult; D001161:Arteriosclerosis / Q000209:etiology / Q000378:metabolism; D003271:Contraceptive Agents, Female / Q000009:adverse effects / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D065366:Cryptoxanthins; D004951:Esterification; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism; D013997:Time Factors; D024341:Xanthophylls; D019207:beta Carotene / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood* / Q000494:pharmacology
D003271:Contraceptive Agents, Female; D065366:Cryptoxanthins; D008077:Lipoproteins, LDL; D024341:Xanthophylls; D019207:beta Carotene; D003300:Copper