Efeitos da fotobiomodulação em um modelo de lesão pulmonar em ratos

Abstract

Introduction: Photobiomodulation has the capacity to modulate the inflammatory response, reducing the infiltration of immune system cells. Its potential action to reduce the inflammatory process could be used as an adjuvant in the treatment of acute respiratory distress syndrome, one of the main causes of hospital admissions. Objective: To analyze how photobiomodulation acts on the recruitment of neutrophils, cytokines, ventilatory mechanics, Myeloperoxidase activity and lung tissue histology in a model of acute lung inflammation in rats. Methods: 288 male Wistar rats had lung injury induced by Escherichia Coli Lipopolysaccharide through tracheal instillation and were subsequently subjected to 430 nm LED, 660 nm Laser and 880 nm Laser radiation. After 24 hours, the animals were mechanically ventilated to analyze resistance, viscosity, elastance and hystesivity and the lung was removed for analysis. Results: Among the phototherapies used, the 660 nm red laser was the only one capable of reducing all variables of ventilatory mechanics, as well as the activity of myeloperoxidase, inflammatory markers in the RT-QPCR analysis with visible repercussions in the analysis of lung histology, being capable of attenuating the pathological process of Lung Injury. The same did not occur with the application of LED, which only changed inflammatory markers, and with the infrared laser (808 nm), which could reduce only tumor necrosis factor and interleukin six, with repercussions on the histological section. Conclusion: The 660 nm red laser was able to modulate the inflammatory process by reducing the cytokine storm in animals with lung injury induced by Escherichia Coli Lipopolysaccharide, with repercussions on ventilatory mechanics and visible in the analysis of lung histology.