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Both Lycopene and β‐carotene metabolism are altered in βC‐15, 15′‐monooxygenase (CMOI) knock‐out mice
Author(s) -
King Jennifer Lyn,
Lindshield Brian,
Wyss Adrian,
Goralczyk Regina,
Erdman John W.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a549-d
Subject(s) - medicine , endocrinology , chemistry , metabolism , cholesterol , carotenoid , lipid metabolism , monooxygenase , vitamin , steatosis , biology , biochemistry , cytochrome p450
βC‐15,15′‐monooxygenase (CMOI) is generally recognized to cleave β‐carotene (BC) and is thought to have minor impact on the cleavage and metabolism of lycopene (LY). We investigated lipid, carotenoid, and vitamin A (VA) levels in wild‐type and CMOI knock‐out mice. For 60 days, C57BL/6x129/SvJ (WT) and B6;129S6‐Bcmo1tm1Dnp (KO) mice ~91 days of age, were fed a high‐fat, marginal vitamin A, cholesterol‐containing diet supplemented with 150 ppm of BC, LY, or placebo (PL) beadlets. Hepatic VA was 6‐fold greater in the BC WT group than BC KO with diet and genotype interaction (DGI) being highly significant. BC feeding had no effect on serum VA. Total hepatic and serum BC was 13‐fold greater in the KO group than in the WT mice fed BC and the DGI was significant. Hepatic LY was 5 fold less in the KO group with the DGI being significant. LY had no effect on hepatic or serum VA. There was no effect of BC or LY diet on hepatic weight, lipids, cholesterol, aortic lipids or cholesterol. Serum total cholesterol increased 15% in LY fed WT mice and decreased 15% in LY fed KO mice and the DGI was significant. These results suggest that CMOI KO mice did not exhibit a compensatory mechanism for converting BC to VA. Surprisingly, the KO group had a much lower hepatic concentration of LY, leading us to hypothesize that in CMOI KO mice there is induction of a second carotenoid cleavage enzyme that results in enhanced metabolism of lycopene. This change in the metabolism of LY may have produced minor biological changes in serum cholesterol levels. (Supported in part by DSM Nutritional Products)