title: Influence of a fat-rich diet, folic acid supplementation and a human-relevant concentration of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine on the induction of preneoplastic lesions in the rat colon.
abstract: In the present study, the effect of three controversially discussed risk factors for colorectal cancer, a fat-rich diet (16% raw fat content), dietary folic acid supplementation (50 mg folic acid/kg lab chow) and a human-relevant concentration (0.1 ppm) of the heterocyclic aromatic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), either alone or in combination, on the induction of aberrant crypt foci (ACF) in the colon of male Fischer 344 rats was analyzed. The mean number of ACF per rat in the case of the four groups fed a fat-rich diet tended to be higher than that of the four groups being fed a standard diet. However, the increase in the mean number of ACF per rat only reached statistical significance in the case of the rats receiving a fat-rich lab chow supplemented with 50 mg/kg folic acid. Moreover, a concentration of 0.1 ppm PhIP per se, either in the standard or in the fat-rich lab chow, did not lead to an increase in the mean number of ACF per rat. In conclusion, the present study provides additional evidence for a colon cancer promoting effect of folic acid supplementation when rodents are fed the compound in supraphysiological concentrations.
authors.affiliation: Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Nicken
authors.forename: Nicole
authors.initials: N
authors.lastname: Brauer
authors.forename: Alfonso
authors.initials: A
authors.lastname: Lampen
authors.forename: Pablo
authors.initials: P
authors.lastname: Steinberg
mesh_terms: D058739:Aberrant Crypt Foci / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000139:chemically induced* / Q000473:pathology; D059305:Diet, High-Fat; D019587:Dietary Supplements; D005492:Folic Acid / Q000009:adverse effects*; D006801:Humans; D007093:Imidazoles / Q000633:toxicity*; D008297:Male; D011230:Precancerous Conditions / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D012307:Risk Factors
chemical_list: D007093:Imidazoles; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine; D005492:Folic Acid