Avaliação da fotobiomodulação na resolução da inflamação pulmonar aguda induzida por sepse

Abstract

Acute respiratory distress syndrome (ARDS) is characterized by rupture of the endothelium and alveolar injury as result by an uncontrolled lung inflammatory response causing gas exchange impairment. Among the main causes of ARDS, sepsis is highlighted, especially in hospital. The restoration of normal lung function is very complicated and a phenomenon difficult to be studied, since the resolution of inflammation is a biochemically active process. Treatment of ARDS is still a clinica l health problem, so new therapies are needed. In this context, photobiomodulation has been showing good results for several inflammatory diseases, including lung diseases. Considering that in previous studies we observed that the treatment with light emitting diode (LED) reduced neutrophil migration in an experimental ARDS model, the present work aimed to evaluate the effect of treatment with LED on the resolution process of acute lung injury induced by lipopolysaccharide (LPS). For this, adult male Bal/c mice were submitted to LPS injection (Salmonella abortus equi, ip) and irradiated or not with LED 2 and 6 h after LPS injection. The parameters were investigated 1, 3 and 7 days after LPS injection. Our results showed that LED treatment was able to attenuate acute lung inflammation induced by sepsis, interfering systemically in the mobilization of cells from their reserve compartments as blood and mainly bone marrow. Importantly, even though two irradiations were performed and the effects of LED were observed up to 7 days after. Further, we note that the LED modulated IL-17A, IL-6, lipoxin A4 and contributed to lower tracheal responsiveness. In this context, the proposed study may provide support for the understanding of the mechanisms that mediate ARDS, as well as allow proposing therapeutic alternatives for this important condition.