Lycopene bioavailability and metabolism in humans: An accelerator mass spectrometry study

Alastair B. Ross, Le Thuy Vuong, Jon Ruckle, Hans Arno Synal, Tim Schulze-König, Karin Wertz, Robert Rümbeli, Rosa G. Liberman, Paul L. Skipper, Steven R. Tannenbaum, Alexandre Bourgeois, Philippe A. Guy, Marc Enslen, Inge Lise F. Nielsen, Sunil Kochhar, Myriam Richelle, Laurent B. Fay, Gary Williamson

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51 Citations (Scopus)

Abstract

Background: To our knowledge, there is no direct information on lycopene metabolism in humans. Objective: The objective of this study was to quantify the long-term human bioavailability of lycopene in plasma and skin after a single dose of 14C-lycopene and to profile the metabolites formed. Design: We preselected 2 male subjects as lycopene absorbers and gave them an oral dose of 10 mg synthetic lycopene combined with ≈6 μg [6,6′,7,7′- 14C]lycopene (≈30,000 Bq; 92% trans lycopene). The appearance of 14C in plasma, plasma triacylglycerol-rich lipoprotein (TRL) fraction, urine, expired breath carbon dioxide, and skin biopsies was measured over 42 d. The 14C in lycopene-isomer fractions from plasma and TRL fraction was measured to assess the isomerization of lycopene in vivo. Results: We quantified 14C from 14C-lycopene in plasma, the plasma TRL fraction, expired carbon dioxide, urine, and skin. The time to maximum concentration (tmax) of total 14C-lycopene in plasma was 6 h, and the elimination half-life (t1/2) was 5 d, which were different from the tmax and t1/2 of unlabeled lycopene (0.5 and 48 d, respectively). 14C-Lycopene was extensively isomerized after dosing as a 92% all-trans isomer at dosing but changed to 50% trans, 38% 5 cis, 1%9cis, and 11% other cis isomers after 24 h. A similar pattern of isomerization was seen in plasma TRL fractions. Conclusions: Lycopene was extensively isomerized after dosing and rapidly metabolized into polar metabolites excreted into urine with the rapid peak of 14CO 2 after dosing, which implies that β-oxidation was involved in the lycopene metabolism. Lycopene or its metabolites were detected in skin for up to 42 d.

Original languageEnglish
Pages (from-to)1263-1273
Number of pages11
JournalThe American Journal of Clinical Nutrition
Volume93
Issue number6
DOIs
Publication statusPublished - 1 Jun 2011
Externally publishedYes

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