Search results for "CARCINOGENESE"
showing 10 items of 15 documents
Garlic and Cancer
2007
Special Issue; International audience; This review summarizes current knowledge on the anticarcinogenic properties of garlic. Collectively epidemiologic studies – mostly casecontrol studies – provide strong evidence that garlic consumption reduces the risk of cancer especially, the risk of gastric and colon cancer. Furthermore many experimental studies demonstrate that organosulfur compounds (OSCs) and garlic extracts can prevent or slow down the carcinogenic process induced by a variety of chemical carcinogens in animals. Garlic and OSCs have been shown to be active during all the stages of carcinogenesis. Several mechanisms have been proposed to explain the cancer-preventive effects of ga…
Comparison of the chemopreventive efficacies of garlic powders with different alliin contents against aflatoxin B1 carcinogenicity in rats
2004
Garlic (Allium sativum) is well known for its beneficial effects on health and particularly for its chemopreventive potential against cancer. The present study was designed to compare the chemopreventive efficacies of several garlic powders with various levels of alliin, a precursor of active sulfur compounds. For this purpose we used the medium-term hepatocarcinogenesis protocol (resistant hepatocyte model), which allows the detection of preneoplasic foci expressing the placental form of glutathione S-transferase (GST-P) as an end-point. Rats were fed diets containing three garlic powders (5% of the diet) with various alliin contents for 3 weeks. Garlic powders were obtained from bulbs gro…
In vivo antigenotoxic effects of dietary allyl sulfides in the rat
1997
The effects of dietary administration of diallyl sulfide (DAS), diallyl disulfide (DADS) and allyl mercaptan (AM) on the genotoxicity of different chemicals were studied in two experimental systems: (i) measurement of hepatic DNA single-strand breaks induced in rats by aflatoxin B1 (AFB1), N-nitrosodimethylamine (NDMA) or methylnitrosourea (MNU); (ii) mutagenicity of AFB1 or NDMA on Salmonella typhimurium TA100 using hepatic S9 from rats fed allyl sulfides as the activation system. All compounds strongly reduced hepatic DNA breaks induced by AFB1 and NDMA but did not modify the genotoxicity of MNU. In the Ames test, the mutagenicity of NDMA was strongly inhibited by hepatic S9 from rats fed…
Modulation of aflatoxin B1 carcinogenicity, genotoxicity and metabolism in rat liver by dietary carotenoids: evidence for a protective effect of CYP1…
1997
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…
Dietary carotenoids inhibit aflatoxin B1-induced liver preneoplastic foci and DNA damage in the rat: Role of the modulation of aflatoxin B1 metabolism
1998
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…
Microconstituants végétaux présumés protecteurs
1996
201 ref. chap. 24; National audience
Canthaxanthin , astaxanthin and beta-apo-8'- carotenal are strong inducers of liver P450 1A1 and 1A2 in the rat
1995
International audience
Effects of provitamin A or non-provitamin A carotenoids on liver xenobiotic-metabolizing enzymes in mice
1997
International audience
Vitamine A, caroténoïdes et cancer
1996
74 ref. chap. 17; National audience
Caroténoïdes et cancérogénèse : influence de caroténoïdes alimentaires sur l'initiation de la cancérogénèse chimique
1993
National audience