Abstract
Some previous studies reported that probiotics might decrease the severity of chemotherapy-induced mucositis. This study assessed the potential protective effect of Lactobacillus plantarum ATCC 8014 on 5-fluorouracil (5-FU) induced intestinal mucositis in the Wistar rats. The Crl:WI rats were divided into two groups of six animals (F, L) and one group of 5 animals (M). Group L received for 9 days 3.32x109 CFU/ml of Lactobacillus plantarum orally. In the 7th day of the experiment 400 mg of 5-FU was administered intraperitoneally in groups L and F. Group M received only the vehicles. All animals were sacrificed in the 9th day. Eleven histological characteristics of mucositis were quantified from 0 (normal) to 3 (severe) for duodenum, jejunum and colon. Semiquantitative grades measured Toll-like receptor 4 (TLR4) immunopositive cells. The independent groups were analyzed using the Kruskal-Wallis test, Mann-Whitney U test, with a Bonferroni correction for alpha (P≤0.016). In the group F, treated with 5-FU, the most affected areas were the jejunum and the duodenum. The medium score of histological lesions was 27 for jejunum (minimum 25, maximum 32) and 21 for duodenum (minimum 18, maximum 29). Graded microscopic mucosal changes of the jejunum were significantly lower in group L compared with group F (U=0, P=0.009, Mann-Whitney test). The histological changes depicted on the duodenal and colonic mucosa were less severe in group L than in group F, but without reaching the statistical significance (duodenum: U=6, P=0.172, Mann-Whitney test; colon: U=12, P=0.916, Mann-Whitney test). Although the TLR4 immunoexpression was more intense in group L, no significant statistical difference was revealed at duodenum, jejunum or colonic mucosa. Significantly fewer microscopic changes were depicted in L group on the jejunum, suggesting a potential beneficial effect of Lactobacillus plantarum at this level in 5-FU induced mucositis.