Low Level Laser Therapy (830nm) Decreases Lps-Induced Acute Respiratory Distress Syndrome Independent Of Il-10 Release

Low-level laser therapy (LLLT) is growing rapidly as an accredited anti-inflammatory therapy. However, its effects in models of inflammatory lung diseases are unknown. Therefore, this study investigated the effects of LLLT in two models of LPS-induced acute respiratory distress (ARDS). Intratracheal(i.t) LPS (10ug/mouse) and intraperitoneal (i.p) LPS (100ug/mouse) were used. LLLT consisted of (laser at 830nm, 3J/cm², 35mW, 80 seconds per point 3 points per application) in direct contact with the skin, beginning one hour after LPS administration, repeated consecutively for three times. BALB/c male mice were divided into control (n=6), LPS i.t (n=7), LPS i.p (n=7), LPS i.t. + LLLT (n=9), LPS i.p. + LLLT (n=9). Twenty-four hours after LPS administration, the animals were euthanized for evaluation of pulmonary inflammation by: Total and differential cell counts in bronchoalveolar lavage (BAL), analysis of cytokines levels in BAL and in serum (IL-1beta, IL-6, KC, and TNF-alpha) and through the quantitative analysis of the number of neutrophils in the lung parenchyma. The results showed that LLLT significantly reduced the levels LPS i.t. and LPS i.p. induce ARDS as demonstrated by reduced number of total cells (pu003c0.001) and neutrophils (pu003c0.001) in the BAL, reduced levels of IL-1beta, IL-6, KC, and TNF-alpha in BAL and in serum (pu003c0.001), beyond the number of neutrophils in the lung parenchyma (pu003c0.001). On the other hand, LLLT have not increased IL-10 levels. We conclude that low-level laser therapy at 830nm is effective in reducing pulmonary and systemic inflammation in models of LPS-induced ARDS independent of the etiology of the disease.