Low level laser therapy reduces acute lung inflammation in a model of pulmonary and extrapulmonary LPS-induced ARDS

J Photochem Photobiol B. 2014 May 5;134:57-63. doi: 10.1016/j.jphotobiol.2014.03.021. Epub 2014 Apr 4.


The present study aimed to investigate the effects low level laser therapy (LLLT) in a LPS-induced pulmonary and extrapulmonary acute respiratory distress syndrome (ARDS) in BALB/c mice. Laser (830nm laser, 9J/cm(2), 35mW, 80s per point, 3 points per application) was applied in direct contact with skin, 1h after LPS administration. Mice were distributed in control (n=6; PBS), ARDS IT (n=7; LPS orotracheally 10μg/mouse), ARDS IP (n=7; LPS intra-peritoneally 100μg/mouse), ARDS IT+Laser (n=9; LPS intra-tracheally 10μg/mouse), ARDS IP+Laser (n=9; LPS intra-peritoneally 100μg/mouse). Twenty-four hours after last LPS administration, mice were studied for pulmonary inflammation by total and differential cell count in bronchoalveolar lavage (BAL), cytokines (IL-1beta, IL-6, KC and TNF-alpha) levels in BAL fluid and also by quantitative analysis of neutrophils number in the lung parenchyma. LLLT significantly reduced pulmonary and extrapulmonary inflammation in LPS-induced ARDS, as demonstrated by reduced number of total cells (p<0.001) and neutrophils (p<0.001) in BAL, reduced levels of IL-1beta, IL-6, KC and TNF-alpha in BAL fluid and in serum (p<0.001), as well as the number of neutrophils in lung parenchyma (p<0.001). LLLT is effective to reduce pulmonary inflammation in both pulmonary and extrapulmonary model of LPS-induced ARDS.

Keywords: ARDS; Bronchoalveolar lavage; Cytokines; LLLT; LPS; Lung inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Animals
  • Bronchoalveolar Lavage Fluid / chemistry
  • Bronchoalveolar Lavage Fluid / cytology
  • Cytokines / blood
  • Cytokines / metabolism
  • Disease Models, Animal
  • Inflammation* / pathology
  • Lipopolysaccharides / toxicity
  • Low-Level Light Therapy*
  • Lung / metabolism*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Neutrophils / cytology
  • Respiratory Distress Syndrome / etiology
  • Respiratory Distress Syndrome / pathology
  • Respiratory Distress Syndrome / radiotherapy*


  • Cytokines
  • Lipopolysaccharides