Pharmacological intervention of cyclooxygenase-2 pathway: impact on control of parasite burden and oxidative stress in erythrocytes evaluated by chemiluminescence during T. cruzi infection

• Autor: V L H Tatakihara
• C L Borges; A D Malvezi; V K Graça-de-Souza; S F Yamada-Ogatta; Luiz Vicente Rizzo; R Cecchini; P Pinge-Filho; Meeting of the Brazilian Society for Immunology (31. 2006 Búzios)
• Assuntos: IMUNOLOGIA
• É parte de: Abstracts São Paulo, SP: Brazilian Society for Immunology, 2006
• Notas: Disponível em CD-ROM
  
• Descrição: Introduction and Objectives: Eicosanoids are potent biologically active arachidonic acidderived lipid mediators that are intimately involved in inflammation and cancer. Cyclooxygenase (COX), the key enzyme in prostaglandin (PG) biosynthesis, controls one of the major pathways of arachidonic acid metabolism and is the main target for non-steroidal anti-inflammatory drugs (NSAIDs). COX exists in two distinct isoforms, COX-1 and COX-2, the latter being primarily involved in inflammation and cell proliferation. For this reason, in recent years, selective COX-2 inhibitors, that achieve the same anti-inflammatory efficacy as traditional NSAIDs but minimize the risk of unwanted side effects, have been developed. We investigated the effects of inhibition of COX-2 on control of parasite burden and erythrocyte oxidative stressing during Trypanosoma cruzi infection in C56BL/6. Methods and Results: We assessed oxidative stress in erythrocytes from mice infected treated or not with celecoxib (50mg/Kg/mice) by measuring oxyhaemoglobin and haemoglobin derivatives (i.e., methaemoglobin and hemichrome), oxygen uptake and induction time (T ind) following treatment with t-butyl hydroperoxide (t-BHT). The involvement of COX-2 in oxidative stress in erythrocytes was also investigated using a specific and sensitive chemiluminescence (CL) method for measurement of membrane lipid peroxide. We found that COX-2 inhibition decreased the erythrocyte oxidative
  stress an acute infection of mice with T. cruzi. Treatment with celecoxib significantly increased blood, macrophage and cardiac parasitism. Conclusion: Taken together, these data suggest that COX-2 play an essential role in controlling parasite burdens, as well as, in the regulation of oxidative stress during acute phase of experimental infection with T. cruzi.
  
• Editor: São Paulo
  
• Data de criação/publicação: 2006
  
• Formato: res. IP.015.
  
• Idioma: Inglês