Avaliação do estresse oxidativo, dano genotóxico e apoptose em células mononucleares de pacientes portadores de malária causada pelo Plasmodium vivax

• Autor(a) principal: Pepato, Marco Andrey
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/1575
• topic: Malária; Estresse oxidativo; Dano no DNA; CNPQ::CIENCIAS DA SAUDE::MEDICINA; Malaria; Oxidative stress; DNA damage

Malaria is one of the major infectious disesses that plague mankind and is considered one of the most important public health problems in the world. Malaria vivax is an endemic disease in Amazon region, corresponding to more than 80% of registered cases. The infection increases the production of reactive oxygen species (ROS), a harmful agent to macromolecules such as DNA, which may lead cells to apoptosis induction. The aim of this study was to evaluate the basal level of DNA damage, as well as apoptosis frequency, antioxidant enzymes activity and the presence of an oxidative stress marker in samples of periphery blood of patients infected with Plasmodium vivax and healthy controls. Samples of 80 patients and 76 controls were submitted to the comet assay to evaluate genotoxicity, having tail moment as a parameter. Apoptosis (measured by caspase 3 activity) and the activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) enzymes were performed using commercial kits. Malondialdheide (MDA) was detected by tiobarbituric acid reaction (TBA). The results showed that mononuclear cells of malaria patients presented higher levels of basal DNA damage (TM=26,71) when compared to controls (TM=10,05) (p=<0,0001). The frequency of apoptotic cells also was significantly increased (p=<0,0001) in patients (39,3 %) in comparison to controls (21,6%), as well as of MDA levels (2,48 µM e 1,93 µM, respectively). There was no difference between both groups in relationship to SOD activity; however, GPx activity was significantly higher (p= 0,0005) in patients (7666,9 U/L) when compared to controls (6386,6 U/L). There was no significant correlation between DNA damage and SOD, GPx and MDA; however, there was a significant negative correlation between DNA damage and apoptosis (r= -0,30, p=0,006) and between MDA and apoptosis (r= -0,34, p=0,001). The results demonstrate that malaria vivax infection increases the oxidative stress, which has significative genotoxic and citotoxic effects on mononuclear cells of malaria patients.