Submitted to: Carotenoid Symposium
Publication Type: Abstract only
Publication Acceptance Date: 10/15/2001
Publication Date: 1/1/2002
Citation: LIU, C., CHING, J., FERREIRA, A., KRINSKY, N.I., RUSSELL, R.M., WANG, X. FORMATION OF EXCENTRIC CLEVAGE PRODUCTS OF LYCOPENE IN THE LUNG OF FERRETS AFTER LYCOPENE SUPPLEMENTATION. INTERNATIONAL CAROTENOID SYMPOSIUM. 2002;141. Interpretive Summary:
Technical Abstract: Recent supporting evidence for a protective role of lycopene against the risk of lung and prostate cancer has been reported in both human epidemiological studies and animal studies. However, the metabolism of lycopene remains poorly understood in vivo. In the present study, ferrets were supplemented with or without lycopene (4.6 mg/kg BW/day) in a tomato oleoresin-corn oil mixture for 9 weeks. Several metabolites of lycopene and three isomers of lycopene were detected using high-performance liquid chromatography (HPLC) in the lungs of ferrets after the lycopene supplementation. The mean concentrations of total lycopene in lung tissue of ferrets were 1.2 +/- 0.30 nmol/g wet weight tissue. Alltrans-lycopene was the predominant isomer (73%) found in the lung tissues of ferrets, whereas 13-cis-lycopene and 9-cis-lycopene was 21% and 6%, respectively. At least three metabolites of lycopene were detected and two of them were identified as apo-10'- and 12'-lycopenal by comparing retention times in HPLC and spectra analysis in the lung tissue of ferrets supplemented with lycopene. The amount of apo-10'-lycopenal and apo-12'-lycopenal in the lung were quantified as 0.03 +/- 0.02 nmol/g and 0.23 +/- 0.11 nmol/g, respectively. We also examined a mRNA encoding the carotene-9', 10'-dioxygenase, catalyzing the excentric cleavage of lycopene and beta-carotene at the 9', 10' double bond, in the lungs of ferrets using RT-PCR method described by Kiefer et al (JBC, 2001). Further, the carotene-9',10'-dioxygenase is expressed in the lungs of ferrets. These data indicate that lycopene can be converted into apo-lycopenals via an excentric cleavage mechanism in the lung of ferret in vivo, and ferret may be a useful model for studying human lycopene metabolism.