beta-Carotene metabolites enhance inflammation-induced oxidative DNA damage in lung epithelial cells.

Y.G.J. van Helden, J. Keijer, A.M. Knaapen, S.G. Heil, J.J. Briede, F.J. van Schooten, R.W. Godschalk*

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review


    beta-Carotene (BC) intake has been shown to enhance lung cancer risk in smokers and asbestos-exposed subjects (according to the ATBC and CARET studies), but the mechanism behind this procarcinogenic effect of BC is unclear. Both smoking and asbestos exposure induce an influx of inflammatory neutrophils into the airways, which results in an increased production of reactive oxygen species and formation of promutagenic DNA lesions. Therefore, the aim of our study was to investigate the effects of BC and its metabolites (BCM) on neutrophil-induced genotoxicity. We observed that the BCM vitamin A (Vit A) and retinoic acid (RA) inhibited the H(2)O(2)-utilizing enzyme myeloperoxidase (MPO), which is released by neutrophils, thereby reducing H(2)O(2) conversion. Moreover, BC and BCM were able to increase (.)OH formation from H(2)O(2) in the Fenton reaction (determined by electron spin resonance spectroscopy). Addition of Vit A and RA to lung epithelial cells that were co-incubated with activated neutrophils resulted in a significant increase in the level of oxidized purines assessed by the formamidopyrimidine DNA glycosylase-modified comet assay. These data indicate that BCM can enhance neutrophil-induced genotoxicity by inhibition of MPO in combination with subsequent increased formation of hydroxyl radicals.
    Original languageEnglish
    Pages (from-to)299-304
    JournalFree Radical Biology and Medicine
    Issue number2
    Publication statusPublished - 1 Jan 2009

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