title: Heme-induced biomarkers associated with red meat promotion of colon cancer are not modulated by the intake of nitrite.
abstract: Red and processed meat consumption is associated with the risk of colorectal cancer. Three hypotheses are proposed to explain this association, via heme-induced oxidation of fat, heterocyclic amines, or N-nitroso compounds. Rats have often been used to study these hypotheses, but the lack of enterosalivary cycle of nitrate in rats casts doubt on the relevance of this animal model to predict nitroso- and heme-associated human colon carcinogenesis. The present study was thus designed to clarify whether a nitrite intake that mimics the enterosalivary cycle can modulate heme-induced nitrosation and fat peroxidation. This study shows that, in contrast with the starting hypothesis, drinking water added with nitrite to mimic the salivary nitrite content did not change the effect of hemoglobin on biochemical markers linked to colon carcinogenesis, notably lipid peroxidation and cytotoxic activity in the colon of rat. However, ingested sodium nitrite increased fecal nitroso-compounds level, but their fecal concentration and their nature (iron-nitrosyl) would probably not be associated with an increased risk of cancer. We thus suggest that the rat model could be relevant for study the effect of red meat on colon carcinogenesis, in spite of the lack of nitrite in the saliva of rats.
authors: Department of Biology, Université Djillali Liabes, Sidi Bel Abbes, Algeria.
authors: Fatima Z
authors: FZ
authors: Chenni
authors: Sylviane
authors: S
authors: Taché
authors: Nathalie
authors: N
authors: Naud
authors: Françoise
authors: F
authors: Guéraud
authors: Ditte A
authors: DA
authors: Hobbs
authors: Gunter G C
authors: GG
authors: Kunhle
authors: Fabrice H
authors: FH
authors: Pierre
authors: Denis E
authors: DE
authors: Corpet
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000378:metabolism* / Q000652:urine; D001835:Body Weight; D003110:Colonic Neoplasms / Q000209:etiology*; D004195:Disease Models, Animal; D060766:Drinking Water; D004435:Eating; D005243:Feces / Q000737:chemistry; D006418:Heme / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008460:Meat / Q000009:adverse effects*; D009573:Nitrites / Q000494:pharmacology*; D009603:Nitroso Compounds / Q000378:metabolism; D011916:Rats, Inbred F344; D012463:Saliva / Q000378:metabolism; D012977:Sodium Nitrite / Q000494:pharmacology; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: C501116:1,4-dihydroxynonene mercapturic acid; D015415:Biomarkers; D060766:Drinking Water; D009573:Nitrites; D009603:Nitroso Compounds; D017392:Thiobarbituric Acid Reactive Substances; D006418:Heme; D012977:Sodium Nitrite; D000111:Acetylcysteine