RESUMEN
PURPOSE: Gastrointestinal mucositis is a major problem associated with cancer therapy. To minimize these deleterious effects, simultaneous administration of antioxidant components, such as selenium, can be considered. There is a growing interest in the use of yeasts because they are able to convert inorganic selenium into selenomethionine. In the present study, oral administration of Saccharomyces cerevisiae UFMG A-905 enriched with selenium was evaluated as an alternative in minimizing the side effects of 5FU-induced mucositis in mice. METHODS: Mice body weight, food consumption, faeces consistency and the presence of blood in faeces were assessed daily during experimental mucositis induced by 5-fluorouracil (5FU). Blood was used for intestinal permeability determination, and small intestine for oxidative stress, immunological and histopathological examination. RESULTS: The increased intestinal permeability observed with mucositis induction was partially reverted by S. cerevisiae and selenium-enriched yeast. Both treatments were able to reduce myeloperoxidase activity, but only selenium-enriched yeast reduced eosinophil peroxidase activity. CXCL1/KC levels, histopathological tissue damage and oxidative stress (lipid peroxidation and nitrite production) in the small intestine were reduced by both treatments; however, this reduction was always higher when treatment with selenium-enriched yeast was evaluated. CONCLUSIONS: Results of the present study showed that the oral administration of S. cerevisiae UFMG A-905 protected mice against mucositis induced by 5-FU, and that this effect was potentiated when the yeast was enriched with selenium.