Avaliação do efeito quimiopreventivo de Brassica oleracea (variedade acephala) e do omeprazol em um modelo experimental de indução do refluxo duodenogastroesofágico

• Ano de defesa: 2009
• Autor(a) principal: Wisnieski, Fernanda [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Esofagite de refluxo; Brassica; Teste do micronúcleo; Esofagite péptica
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9081

Aim: To evaluate, in an experimental model, the applicability of erythrocyte micronucleus assay in diagnosis of esophageal damage caused by gastroesophageal reflux disease (GERD) and to investigate the chemopreventive effect of Brassica oleracea extract and Omeprazole pump inhibitor drug. Methods: Brassica oleracea dose of 500 mg/Kg was determined using in vitro and in vivo toxicity tests. Male Wistar rats underwent esophagojejunostomy model to produce duodeno-gastroesophageal reflux. Eight weeks after surgical procedure, animals were treated with 500 mg/Kg of Brassica oleracea extract or 30 mg/Kg of Omeprazole for four weeks. The animals were weighed once a week. After the last treatment, the esophagus of each animal was removed for histological analysis, as well as, blood and bone marrow samples were obtained for erythrocyte micronucleus test. Results: Body weights of Reflux group were significantly lower than Control group (p < 0.0001). This difference was not observed among treatments. All non-treated animals of Reflux group developed severe esophagitis and one animal developed squamous cell carcinoma type twelve weeks after surgery. Omeprazole-treated animals developed lower incidence of spongiosis (p = 0.028) and lower grade of esophagitis (p = 0.018) compared to non-treated animals. Whereas the animals treated with Brassica oleracea extract showed the same results, no significant difference was observed. Micronucleated erythrocytes and micronucleus frequencies did not differ signicantly among groups and treatments and were not associated with histological alterations. Conclusions: The esophagojejunostomy model allowed the study of GERD progression ultil severe esophagitis. The Omeprazole treatment reduced the inflammatory process in esophageal mucosa and this effect was only indicative in Brassica oleracea treatment. The cell types evaluated by micronucleus assay did not reproduce the esophageal characteristics determined histologically. Considering the importance of this test in investigation of genotoxicity of various substances in vivo, the evaluation of esophageal cells exposed directly to reflux could show the real alterations caused by GERD, as well as the possible effects of Brassica oleracea extract and Omeprazole treatments.