title: Dietary chemoprevention of PhIP induced carcinogenesis in male Fischer 344 rats with tomato and broccoli.
abstract: The heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-B]pyridine (PhIP), found in meats cooked at high temperatures, has been implicated in epidemiological and rodent studies for causing breast, prostate, and colorectal cancers. A previous animal study using a xenograft model has shown that whole tomato and broccoli, when eaten in combination, exhibit a marked effect on tumor reduction compared to when eaten alone. Our aim was to determine if PhIP-induced carcinogenesis can be prevented by dietary consumption of whole tomato + broccoli powders. Male Fischer 344 rats (n = 45) were randomized into the following treatment groups: control (AIN93G diet), PhIP (200 ppm in AIN93G diet for the first 20 weeks of the study), or tomato + broccoli + PhIP (mixed in AIN93G diet at 10% each and fed with PhIP for 20 weeks, and then without PhIP for 32 weeks). Study animals were monitored for 52 weeks and were euthanized as necessary based on a set of criteria for health status and tumor burden. Although there appeared to be some hepatic and intestinal toxicity due to the combination of PhIP and tomato + broccoli, these rodents had improved survival and reduced incidence and/or severity of PhIP-induced neoplastic lesions compared to the PhIP-alone treated group. Rats eating tomato + broccoli exhibited a marked decrease in the number and size of cribiform prostatic intraepitheilial neoplasia/carcinoma in situ (cribiform PIN/CIS) lesions and in the incidence of invasive intestinal adenocarcinomas and skin carcinomas. Although the apparent toxic effects of combined PhIP and tomato + broccoli need additional study, the results of this study support the hypothesis that a diet rich in tomato and broccoli can reduce or prevent dietary carcinogen-induced cancers.
authors: Department of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America.
authors: Kirstie
authors: K
authors: Canene-Adams
authors: Karen S
authors: KS
authors: Sfanos
authors: Chung-Tiang
authors: CT
authors: Liang
authors: Srinivasan
authors: S
authors: Yegnasubramanian
authors: William G
authors: WG
authors: Nelson
authors: Cory
authors: C
authors: Brayton
authors: Angelo M
authors: AM
authors: De Marzo
mesh_terms: D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D001937:Brassica; D002273:Carcinogens / Q000633:toxicity*; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced*; D018890:Chemoprevention; D019587:Dietary Supplements; D004195:Disease Models, Animal; D051549:Glutathione S-Transferase pi / Q000378:metabolism; D007093:Imidazoles / Q000633:toxicity*; D007150:Immunohistochemistry; D008055:Lipids / Q000097:blood; D018551:Solanum lycopersicum; D008297:Male; D009369:Neoplasms / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D009929:Organ Size; D051381:Rats
chemical_list: D002273:Carcinogens; D007093:Imidazoles; D008055:Lipids; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine; D051549:Glutathione S-Transferase pi