Efeito do Laser de Baixa Intensidade (LBI) sobre o estresse oxidativo pulmonar induzido pela exposição ao formaldeído

Abstract

After the industrial revolution there has been a large increase in the production of consumer goods and inputs for the world population, and the process of obtaining these end products is generated environmental and occupational pollutants, which exposes the population to toxic pollutants and affect disease. Formaldehyde (FA) is a chemical widely used in various industries, laboratories, issued by the burning of fuel and cooking gas also expelled in cigarette smoke, which characterizes it as an environmental and occupational pollutants. Lung oxidative stress induced by exposure to FA is a major respiratory disease model. The overall recognition on the growth of pulmonary inflammatory diseases has led to efforts to develop new therapeutics, particularly for the control of inflammation. Among the therapies used for lung diseases, LLLT has highlighted, being non-invasive, no side effects and anti- inflammatory actions and antioxidants. Studies show beneficial effects to low-intensity laser (LBI) for the treatment of lung disease, but their mechanisms need to be better understood. Thus, pulmonary inflammation models are important tools to extend mechanistic knowledge of LBI. Therefore, we investigated the effects of LLLT in the pulmonary oxidative stress model induced by FA which is already well established. Formaldehyde was used to induce airway inflammation in rats. Next it was examined the cells present in the lung, blood, and bone marrow; gene expression of antioxidant enzymes and oxidants; activity of glutathione enzymes; release of nitrite and hydrogen peroxide, besides the oxidative burst. Our work has shown that low-intensity laser treatment increased gene expression of antioxidant enzymes with concomitant reduction of expression of oxidative enzymes, increased the activity of antioxidant peroxidase glutathione enzymes (GPx) and s-transferase (GST), the level decreased from hydrogen peroxide and nitrite, in addition to increasing the oxidative burst of inflammatory cells. Thus, this study may provide important information of a possible therapy to minimize the undesirable effects of pollutants on health.