title: Diphenyl diselenide supplementation delays the development of N-nitroso-N-methylurea-induced mammary tumors.
abstract: The effect of dietary diphenyl diselenide (1 ppm) on N-nitroso-N-methylurea (NMU)-induced mammary carcinogenesis was examined in female Wistar rats. Beginning at 5 weeks of age, the animals were fed with either control or diphenyl-diselenide-supplied diets until the end of the study (210 days). At 50 days of age, mammary tumor was induced by the administration of three doses of NMU (50 mg/kg body wt, intraperitoneally) once a week for 3 weeks. In experimental trials, latency to tumor onset was extended in rats fed with diet supplemented with diphenyl diselenide (P < 0.05). The incidence and frequency of tumors were significantly small in animals supplemented with diphenyl diselenide. However, the multiplicity of tumors was not altered by dietary diphenyl diselenide. Diphenyl diselenide supplementation also restored superoxide dismutase (SOD) activity and vitamin C levels altered in the NMU group (P < 0.05). Our results suggest that diphenyl diselenide can be considered a chemopreventive agent, even when supplemented at a relatively low concentration.
authors: Centro de Ciências da Saúde, Universidade Federal de Santa Maria-UNIPAMPA, Rua Domingos de Almeida, São Miguel, Uruguaiana, RS, Brazil. nvbarbosa@yahoo.com.br
authors: Nilda Berenice
authors: NB
authors: de Vargas Barbosa
authors: Cristina Wayne
authors: CW
authors: Nogueira
authors: Temenouga N
authors: TN
authors: Guecheva
authors: Maria de Lourdes
authors: Mde L
authors: Bellinaso
authors: João Batista Teixeira
authors: JB
authors: Rocha
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents; D001205:Ascorbic Acid / Q000378:metabolism; D001555:Benzene Derivatives / Q000494:pharmacology*; D015415:Biomarkers; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D020552:Comet Assay; D004032:Diet; D005260:Female; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D015674:Mammary Neoplasms, Animal / Q000139:chemically induced* / Q000517:prevention & control*; D008770:Methylnitrosourea / Q000633:toxicity*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D009929:Organ Size / Q000187:drug effects; D016566:Organoselenium Compounds / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D016588:Anticarcinogenic Agents; D001555:Benzene Derivatives; D015415:Biomarkers; D002273:Carcinogens; D009363:Neoplasm Proteins; D016566:Organoselenium Compounds; C061132:diphenyldiselenide; D008770:Methylnitrosourea; D013482:Superoxide Dismutase; D001205:Ascorbic Acid