0000000000464758
AUTHOR
Pierre Astorg
Induction des cytochromes P450 1A1 et 1A2 et d'autres enzymes du métabolisme des xénobiotiques par des caroténoïdes chez le rat et la souris . Implication du récepteur AH.
National audience
Effects of provitamin A or non-provitamin A carotenoids on liver xenobiotic-metabolizing enzymes in mice
International audience
Modulation of aflatoxin B1 carcinogenicity, genotoxicity and metabolism in rat liver by dietary carotenoids: evidence for a protective effect of CYP1A inducers
The effects of several carotenoids of vitamin A and of 3-methylcholanthrene have been tested on the initiation of hepatocarcinogenesis by aflatoxin B1, using the sequential protocol of Solt and Farber. AFB1-induced DNA single-strand breaks and AFB1-metabolism were also assessed. The P4501A inducer carotenoids (canthaxanthin, astaxanthin, beta-apo-8'-carotenal) and 3-methylcholanthrene reduce the carcinogenicity of AFB1, divert AFB1-metabolism into the less genotoxic aflatoxin M1 and reduce AFB1-induced DNA single-strand breaks: we conclude that these carotenoids exert their protective effect through the deviation of AFB1 metabolism towards detoxification pathways. beta-Carotene decreased AF…
Vitamine A, caroténoïdes et cancer
74 ref. chap. 17; National audience
Dietary carotenoids inhibit aflatoxin B1-induced liver preneoplastic foci and DNA damage in the rat: Role of the modulation of aflatoxin B1 metabolism
To study the effects of carotenoids on the initiation of liver carcinogenesis by aflatoxin B1 (AFB1), male weanling rats were fed beta-carotene, beta-apo-8'-carotenal, canthaxanthin, astaxanthin or lycopene (300 mg/kg diet), or an excess of vitamin A (21000 RE/kg diet), or were injected i.p. with 3-methylcholanthrene (3-MC) (6 x 20 mg/kg body wt) before and during i.p. treatment with AFB1 (2 x 1 mg/kg body wt). The rats were later submitted to 2-acetylaminofluorene treatment and partial hepatectomy, and placental glutathione S-transferase-positive liver foci were detected and quantified. The in vivo effects of carotenoids or of 3-MC on AFB1-induced liver DNA damage were evaluated using diff…
Dietary lycopene decreases the initiation of liver preneoplastic foci by diethylnitrosamine in the rat
To test whether carotenoids can modulate the initiation of liver preneoplasia by diethylnitrosamine (DEN) or by 2-nitropropane (2-NP) in a sequential protocol of hepatocarcinogenesis, male weanling rats were fed for three or four weeks (respectively) diets containing beta-carotene, canthaxanthin, astaxanthin, or lycopene (300 mg/kg diet) or an excess of vitamin A (15,000 retinol equivalents/kg diet) or were treated intraperitoneally with 3-methylcholanthrene. During this period, all rats were injected intraperitoneally with the initiator carcinogen, either 2-NP (6 times at 100 mg/kg body wt) or DEN (once at 100 mg/kg body wt). Three weeks after the termination of carotenoid or vitamin A fee…
Induction of gamma GT- and GST-P positive foci in the liver of rats treated with 2-nitropropane or propane 2-nitronate
International audience
Caroténoïdes et cancérogénèse : influence de caroténoïdes alimentaires sur l'initiation de la cancérogénèse chimique
National audience
Canthaxanthin , astaxanthin and beta-apo-8'- carotenal are strong inducers of liver P450 1A1 and 1A2 in the rat
International audience
Food carotenoids and cancer prevention: an overview of current research
Carotenoids are plant pigments that are present in the human diet as microcomponents of fruit and vegetables. Since 1980, a consistent bulk of the results from both epidemiologic and experimental studies has strongly suggested that β-carotene, a widespread food carotenoid with provitamin A activity, could prevent the onset of cancers, especially lung cancer. Unfortunately, subsequent large-scale intervention studies failed, with one exception, to demonstrate any chemopreventive potency for β-carotene supplementation in humans, revealing a lack of knowledge of the mechanisms involved. In addition to their antioxidant properties, which have long been thought to be the clue to their biological…