Chemoprevention of azoxymethane-induced rat colon carcinogenesis by dietary capsaicin and rotenone

Citation
Si. Yoshitani et al., Chemoprevention of azoxymethane-induced rat colon carcinogenesis by dietary capsaicin and rotenone, INT J ONCOL, 19(5), 2001, pp. 929-939
Citations number
50
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF ONCOLOGY
ISSN journal
1019-6439 → ACNP
Volume
19
Issue
5
Year of publication
2001
Pages
929 - 939
Database
ISI
SICI code
1019-6439(200111)19:5<929:COARCC>2.0.ZU;2-J
Abstract
The modifying effects of dietary administration of capsaicin, which is the principal pungent capsicum fruit, and rotenone, which is a naturally occurr ing pesticide derived from Derris and Lonchorcarpus species, on azoxymethan e (AOM)-induced colon tumorigenesis were investigated in male F344 rats. Ga vage with capsaicin and rotenone significantly elevated phase II enzymes, g lutathione S-transferase (GST) and quinone reductase (QR), in the liver and colon. In an aberrant crypt foci (ACF) bioassay, feeding of capsaicin and rotenone at a dose of 500 ppm for 4 weeks significantly inhibited ACF forma tion induced by AOM (20 mg/kg body weight, once a week for 2 weeks). In a s ubsequent long-term study designed to confirm the protective effects of bot h compounds on ACF development, one group was treated with AOM alone and fo ur other groups received the carcinogen treatment plus diets containing 500 ppm test compounds for 4 weeks (initiation phase) and for 34 weeks (post-i nitiation phase). Two groups were treated with capsaicin or rotenone alone (500 ppm in diet) and one group was maintained on the basal diet. At the te rmination of the study, dietary exposure of capsaicin during the initiation phase was found to significantly reduce the incidence of colonic adenocarc inoma (60% vs. 24%, 60% reduction, P=0.0407). Rotenone feeding during the p ost-initiation phase also reduced the frequency of colonic adenocarcinoma ( 60% vs. 19%, 68% reduction, P=0.0226). Our results suggest that two natural compounds, capsaicin and rotenone, might be useful for the prevention of h uman colon cancers.