Browsing by Author "Mota-Filipe, Helder"
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- Anti-inflammatory effect of erythropoietin in the TNBS-induced colitisPublication . Mateus, Vanessa; Rocha, João; Alves, Paula; Mota-Filipe, Helder; Sepodes, Bruno; Pinto, Rui Manuel AmaroErythropoietin is a potent stimulator of erythroid progenitor cells, which is able to inhibit NF-kB activation, due to its pleiotropic properties, thus promoting an anti-inflammatory effect. As inflammatory bowel disease is a chronic disease with reduced quality of life, and the current pharmacotherapy only induces or maintains the patient in remission, there is a crucial need of new pharmacological approaches. The main objective of this study was to evaluate the effect of erythropoietin in the TNBS-induced colitis model in mice with a normal intestinal flora. Mice with TNBS-induced colitis were treated with a daily dose of erythropoietin at 500 IU/kg bw/day and 1000 IU/Kg bw/day IP during 4 days. As to clinical symptoms/signs, erythropoietin attenuated the decreased body-weight and reduced diarrhoea and oedema of the anus registered in the non-treated mice group in a dose-dependent manner. The anti-inflammatory properties of erythropoietin in the TNBS-induced colitis were confirmed by suppression of pro-inflammatory mediators, such as TNF-α, IL-1β and MPO, as well as a significant increase in the anti-inflammatory cytokine, IL-10, was promoted. These treated mice also presented a reduction in haemoglobin faecal and ALP, suggesting a beneficial effect of erythropoietin in the haemorrhagic focus and destruction of the enterocyte associated with the colon injury induced by TNBS, respectively. The histopathological score was reduced after treatment with erythropoietin, decreasing the severity and extension of the colitis. Furthermore, renal and hepatic biomarkers, as well as haematocrit concentration, remained stabilized after treatment. In conclusion, erythropoietin reduces the inflammatory response associated with TNBS-induced colitis in mice.
- Development of TNBS-induced colitis: animal model to test new pharmacological approachesPublication . Mateus, Vanessa; Faísca, Pedro; Mota-Filipe, Helder; Sepodes, Bruno; Pinto, RuiIBD is a gastro-intestinal disorder marked with chronic inflammation of intestinal epithelium, damaging mucosal tissue and manifests into several intestinal and extra-intestinal symptoms. Currently used medical therapy is able to induce and maintain the patient in remission, however no modifies or reverses the underlying pathogenic mechanism. The research of other medical approaches is crucial to the treatment of IBD and, for this, it´s important to use animal models to mimic the characteristics of disease in real life. The aim of the study is to develop an animal model of TNBS-induced colitis to test new pharmacological approaches. TNBS was instilled intracolonic single dose as described by Morris et al. It was administered 2,5% TNBS in 50% ethanol through a catheter carefully inserted into the colon. Mice were kept in a Tredelenburg position to avoid reflux. On day 4 and 7, the animals were sacrificed by cervical dislocation. The induction was confirmed based on clinical symptoms/signs, ALP determination and histopathological analysis. At day 4, TNBS group presented a decreased body weight and an alteration of intestinal motility characterized by diarrhea, severe edema of the anus and moderate morbidity, while in the two control groups weren’t identified any alteration on the clinical symptoms/signs with an increase of the body weight. TNBS group presented the highest concentrations of ALP comparing with control groups. The histopathology analysis revealed severe necrosis of the mucosa with widespread necrosis of the intestinal glands. Severe hemorrhagic and purulent exsudates were observed in the submucosa, muscular and serosa. TNBS group presented clinical symptoms/signs and histopathological features compatible with a correct induction of UC. The peak of manifestations became maximal at day 4 after induction. This study allows concluding that it’s possible to develop a TNBS induced colitis 4 days after instillation.
- Hemin reduces inflammation associated with TNBS-induced colitisPublication . Mateus, Vanessa; Rocha, João; Mota-Filipe, Helder; Sepodes, Bruno; Pinto, RuiPurpose - Hemin is a heme-oxygenase inducer, which can confer anti-inflammatory, cytoprotective, and antiapoptotic effects. These properties are beneficial therapeutical effects to inflammatory bowel disease (IBD). IBD is a worldwide health problem characterized by chronic inflammation of intestinal epithelium, which promotes intestinal and extraintestinal symptomatology. Current treatment only induces and maintains the patient in remission and results in many side effects. The research of other pharmacologic approaches is crucial to the treatment of IBD. The aim of this study is to evaluate the effect of hemin in the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model. Materials and methods - Male CD-1 mice with TNBS-induced colitis were treated with a daily dose of hemin 5 mg/kg body weight/day and 10 mg/kg body weight/day intraperitoneal, during 4 days. The evaluated parameters were fecal hemoglobin, alkaline phosphatase (ALP), myeloperoxidase, tumor necrosis factor-α, interleukin (IL)-1β, IL-10, histopathologic analysis, urea, creatinine, and alanine aminotransferase. Results - The hemin-treated mice presented a decrease in fecal hemoglobin, ALP, and proinflammatory cytokine concentrations compared to the TNBS group. Histopathology analysis confirmed the decrease in lesion extension produced by hemin. Conclusion - These findings suggest that hemin treatment reduces hemorrhagic focus, intestinal damage, tissue inflammation, and lesion extension associated with experimental colitis.