Dietary Selenium Reduces the Formation of Aberrant Crypts in Rats Administered 3,2′-Dimethyl-4-aminobiphenyl

• Published in: Toxicology and applied pharmacology Vol. 157; no. 1; pp. 36 - 42
• Main Authors: Feng, Yi, Finley, John W., Davis, Cindy D., Becker, William K., Fretland, Adrian J., Hein, David W.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.05.1999; Elsevier
• Subjects: 3,2′-dimethyl-4-aminobiphenyl; aberrant crypt foci; Aminobiphenyl Compounds - toxicity; Animal tumors. Experimental tumors; Animals; anions; aromatic amines; Biological and medical sciences; carcinogenesis; carcinogens; Carcinogens - toxicity; colon; colorectal cancer; Colorectal Neoplasms - chemically induced; Colorectal Neoplasms - prevention & control; Diet; Dose-Response Relationship, Drug; enzyme activity; erythrocytes; Experimental digestive system and abdominal tumors; glutathione peroxidase; humans; inhibition; kidneys; lesions; liver; Male; Medical sciences; mineral content; neoplasms; nutrient availability; nutrient intake; Precancerous Conditions - chemically induced; Precancerous Conditions - prevention & control; Rats; Rats, Inbred F344; rectum; selenate; selenite; selenium; Selenium - pharmacology; selenomethionine; Tumors; aberrant crypt foci; colorectal cancer; selenium; aromatic amines; 3,2′-dimethyl-4-aminobiphenyl; Premalignant lesion; Rat; Rodentia; Oral administration; Supplemented diet; Malignant tumor; Anticarcinogen; Colonic disease; Prevention; Carcinogen; Vertebrata; Mammalia; Amine; Animal; Digestive diseases; Intestinal disease; Aromatic compound; Colon; Selenium; Restricted diet
• ISSN: 0041-008X; 1096-0333
• DOI: 10.1006/taap.1999.8623

Human epidemiologic studies suggest that low selenium status is associated with increased cancer risk and that selenium supplementation is associated with reduction in the incidence of several cancers, including colorectal cancer. Aromatic and heterocyclic amine carcinogens are thought to be important in the etiology of human colorectal cancer, but no information is available on the effects of selenium on aromatic amine-induced colon cancer. In order to investigate this effect, aberrant crypt foci (ACF), the putative preneoplastic lesions of colon cancer in humans and rodents, were used as a biomarker to test the hypothesis that selenium supplementation can reduce aromatic amine-induced colon carcinogenesis. Male weanling F344 inbred rats were fed a basal torula yeast selenium-deficient diet supplemented with 0, 0.1, or 2.0 mg selenium/kg diet as selenite, selenate, or selenomethionine (SeMet). Animals were fed the diets for 4 weeks and then administered 1 sc injection/week for 2 weeks of 3,2′-dimethyl-4-aminobiphenyl (DMABP; 100 mg/kg) or vehicle (peanut oil). At 12 weeks, the rats were euthanized and the colon and rectum were removed, opened longitudinally, and fixed in 70% ethanol. Glutathione peroxidase activities in erythrocytes and liver cytosol and selenium concentrations in the colon/rectum and kidney increased significantly (p< 0.05) and in a dose-dependent manner with each of the three selenium diets. No ACF were identified in vehicle-treated rats. In DMABP-treated rats, ACF frequencies decreased significantly (p< 0.05) in groups supplemented with 0.1 or 2.0 mg selenium/kg diet as selenite and selenate but not SeMet. There were no significant differences in ACF and aberrant crypts between rats fed 0.1 vs 2.0 mg selenium/kg diet. These results suggest that dietary selenium, depending on chemical form, can reduce aromatic amine-induced colon carcinogenesis.