Saccharomyces boulardii reverte a resposta inflamatória e funcional presente na mucosite intestinal induzida por 5-fluorouracil em camundongos

Abstract

Intestinal mucositis is a frequent side-effect associated to 5-fluorouracil (5-FU) clinical use and results in inflammatory events. It is characterized by epithelial ulcerations in the mucosa and clinical manifestations of abdominal pain, nauseas and diarrhea. Saccharomyces boulardii is a probiotic yeast which has been shown to protect the gastrointestinal microflora from disequilibrium and from associated gastrointestinal disorders. Aim: To evaluate the effect of treatment with Saccharomyces boulardii in inflammatory response and alterations in the gastrintestinal motility in the course of intestinal mucositis experimental induced by 5-FU. Methods: Swiss male mice (25-30g) were treated with 5-FU (450mg/Kg, ip) or saline (control). Other groups received 3 or 6 days during SB (800mg/Kg, gavage) until the day of sacrifice, every day. A group pretreated received the SB for 3 days before and 3 days after administration of 5-FU (SB 6D) and another group received SB only 3 days after administration of 5-FU (SB 3D). At day 3 after 5-FU, the animals were sacrificed, samples of jejunum and ileum were collected to assess the injury epithelial morphometry, histological scores, the activity of MPO, nitrite levels and the concentration of GSH. For evaluation of cytokine samples of jejunum and ileum were removed and the ELISA was determined concentrations of IL-1β and CXCL1. In the technique of gastric emptying, the animals received the same treatment described above. Later, they were left to fast for 18 hours from d6 to d7. At d7, were administered 0.3 ml of glucose solution (5%) containing phenol red (VF) to 0.75 mg / ml in each animal. After 20 min, the animals were sacrificed and underwent a laparotomy. The small intestine was exposed and divided into 3 equal parts: proximal, medial and distal. With the aid of a beaker containing a solution of NaOH (100ml, 0.1 N) the volume of the stomach and small intestine segments were determined. The sample absorbance was read in a wavelength of 540 nm. Results: Treatment with 5-FU was able to induce intestinal injury with a significant impairment of epithelial barrier function in the presence of the following changes: severe shortening of the villus, crypts of partial necrosis, vacuolization of cells, infiltration and mono polymorphonuclear free radical production with consumption of GSH, increased levels of nitrite, increased concentration of IL-1β and CXCL1 and changes in gastrointestinal motility. Treatment with SB significantly reduced intestinal damage, with recovery of villous height, crypt depth recovery, decreased neutrophil infiltration and nitrite levels, increased levels of glutathione and reduced concentrations of IL-1β and CXCL1. However, treatment with SB was able to reverse the delayed gastric emptying and gastrointestinal transit. Conclusion: 5-FU induces intestinal mucositis in mice involving IL-1β and CXCL1, which is associated with delayed gastric emptying and gastrointestinal transit in. Treatment with SB, both 3D and 6D, were able to reverse the inflammatory changes, and revert the changes in gastrointestinal motility associated with mucositis by 5 - FU in mice.