Miranda da Silva Cristiane, Peres Leal Mayara, Brochetti Robson Alexandre, Braga Tárcio, Vitoretti Luana Beatriz, Saraiva Câmara Niels Olsen, Damazo Amílcar Sabino, Ligeiro-de-Oliveira Ana Paula, Chavantes Maria Cristina, Lino-Dos-Santos-Franco Adriana
Post Graduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, Brazil.
Department of Immunology, University of São Paulo, São Paulo, Brazil.
PLoS One. 2015 Nov 16;10(11):e0142816. doi: 10.1371/journal.pone.0142816. eCollection 2015.
Lung diseases constitute an important public health problem and its growing level of concern has led to efforts for the development of new therapies, particularly for the control of lung inflammation. Low Level Laser Therapy (LLLT) has been highlighted as a non-invasive therapy with few side effects, but its mechanisms need to be better understood and explored. Considering that pollution causes several harmful effects on human health, including lung inflammation, in this study, we have used formaldehyde (FA), an environmental and occupational pollutant, for the induction of neutrophilic lung inflammation. Our objective was to investigate the local and systemic effects of LLLT after FA exposure. Male Wistar rats were exposed to FA (1%) or vehicle (distillated water) during 3 consecutive days and treated or not with LLLT (1 and 5 hours after each FA exposure). Non-manipulated rats were used as control. 24 h after the last FA exposure, we analyzed the local and systemic effects of LLLT. The treatment with LLLT reduced the development of neutrophilic lung inflammation induced by FA, as observed by the reduced number of leukocytes, mast cells degranulated, and a decreased myeloperoxidase activity in the lung. Moreover, LLLT also reduced the microvascular lung permeability in the parenchyma and the intrapulmonary bronchi. Alterations on the profile of inflammatory cytokines were evidenced by the reduced levels of IL-6 and TNF-α and the elevated levels of IL-10 in the lung. Together, our results showed that LLLT abolishes FA-induced neutrophilic lung inflammation by a reduction of the inflammatory cytokines and mast cell degranulation. This study may provide important information about the mechanisms of LLLT in lung inflammation induced by a pollutant.
肺部疾病是一个重要的公共卫生问题，人们对其关注度的不断提高促使了新疗法的研发，尤其是用于控制肺部炎症的疗法。低强度激光疗法（LLLT）作为一种副作用较少的非侵入性疗法受到了关注，但其作用机制仍需深入了解和探索。考虑到污染会对人类健康造成多种有害影响，包括肺部炎症，在本研究中，我们使用了甲醛（FA），一种环境和职业污染物，来诱导嗜中性粒细胞性肺部炎症。我们的目的是研究FA暴露后LLLT的局部和全身效应。雄性Wistar大鼠连续3天暴露于FA（1%）或溶剂（蒸馏水）中，并在每次FA暴露后1小时和5小时接受或不接受LLLT治疗。未进行处理的大鼠作为对照。在最后一次FA暴露后24小时，我们分析了LLLT的局部和全身效应。LLLT治疗减少了FA诱导的嗜中性粒细胞性肺部炎症的发展，表现为肺内白细胞数量减少、肥大细胞脱颗粒以及髓过氧化物酶活性降低。此外，LLLT还降低了肺实质和肺内支气管的微血管通透性。肺部炎症细胞因子水平的变化表现为IL-6和TNF-α水平降低以及IL-10水平升高。总之，我们的结果表明，LLLT通过减少炎症细胞因子和肥大细胞脱颗粒来消除FA诱导的嗜中性粒细胞性肺部炎症。本研究可能为LLLT在污染物诱导的肺部炎症中的作用机制提供重要信息。
