Numerous studies have been conducted in an attempt to clarify the relationship between bêta-carotene and cancer chemoprevention, assumed to exist on the basis of an inverse association between fruit and vegetable intake, or blood levels of bêta-carotene, and cancer risk, suggested in observational epidemiologic studies.
The chemopreventive action of the carotenoid has been observed in both in vitro and in vivo experimental models of carcinogenesis.
Several cellular and molecular mechanisms have been proposed to explain the anticarcinogenic effect of bêta-carotene, with emphasis on its metabolic conversion to retinoids, its antioxidant action and, more recently, its eventual modulatory action at the gene expression level.
On the other hand, in intervention trials, bêta-carotene was found to be deleterious to smokers.
Some cell mechanisms are indicated here to explain this adverse effect of the carotenoid, causing a probable chronic prooxidant action that potentiates the oxidative state present in the lungs of these individuals during an advanced promotional phase of the carcinogenic process.
In this respect, more basic research is needed, especially using an animal model of pulmonary carcinogenesis that will permit to investigate in a distinct manner the effect of the carotenoid on the initiation, promotion and progression steps of carcinogenesis. (...)
Mots-clés Pascal : Régime alimentaire, Bétacarotène, Anticarcinogène, Antioxydant, Mécanisme action, Epidémiologie, Tumeur maligne, Prévention, Alimentation, Etat nutritionnel, Caroténoïde, Article synthèse
Mots-clés Pascal anglais : Diet, Betacarotene, Anticarcinogen, Antioxidant, Mechanism of action, Epidemiology, Malignant tumor, Prevention, Feeding, Nutritional status, Carotenoid, Review
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0466089
Code Inist : 002A16E. Création : 19/02/1999.