Low level laser therapy reduces acute lung inflammation without impairing lung function

Abstract

Acute lung injury is a condition characterized by exacerbate inflammatory reaction in distal airways and lung dysfunction. Here we investigate the treatment of acute lung injury (ALI) by low level laser therapy (LLLT), an effective therapy used for the treatment of patients with inflammatory disorders or traumatic injuries, due to its ability to reduce inflammation and promote tissue regeneration. However, studies in internal viscera remains unclear. C57BL/6 mice were treated with intratracheal lipopolysaccharide (LPS) (5 mg/kg) or phosphate buffer saline (PBS). Six hours after instillation, two groups were irradiated with laser at 660 nm and radiant exposure of 10 J/cm . Intratracheal LPS inoculation induced a marked increase in the number of inflammatory cells in perivascular and alveolar spaces. There was also an increase in the expression and secretion of cytokines (TNF-α, IL-1β, IL-6,) and chemokine (MCP-1). The LLLT application induced a significant decrease in both inflammatory cells influx and inflammatory mediators secretion. These effects did not affect lung mechanical properties, since no change was observed in tissue resistance or elastance. In conclusion LLLT is able to reduce inflammatory reaction in lungs exposed to LPS without affecting the pulmonary function and recovery.

Photobiomodulation therapy as a high potential treatment modality for COVID-19

“…Other experimental and clinical investigations also reported the positive effects of PBM on acute and chronic pulmonary inflammation, and acute pulmonary inflammation induced by intestinal ischemic-reperfusion [22][23][24]. Also, it has been observed that PBM may be useful for decreasing pulmonary fibrosis [25].…”

“…ARDS patients show an increased level of IL-6 in the lungs and plasma. PBM has been able to decrease IL-6 levels both in the lungs and plasma in ARDS mice [20,23]. IL-8 contributes to ARDS pathophysiology, neutrophil chemotaxis, and survival in the lung.…”

“…Several studies reported that PBM might play a substantial role in managing all the aforementioned immune responses, including the increased number of PMNs, monocytes, and macrophages; the release of pro-inflammatory cytokines; and collagen deposition. In addition to the inhibitory effect on inflammatory cell chemotaxis, PBM can also decrease the number of present leukocytes in inflammation sites [23].…”

“…TNFα level is usually high in the serum and lung of ARDS patients. PBM has been shown to be useful in decreasing TNFα levels at both sites [20,23]. MCP-1 has a crucial role in recruiting monocytes, and its level increases in pulmonary inflammation.…”

Verification of the Effects of Red Light-emitting Diode Therapy on Acute Lung Injury in a Sepsis Model in Rats

“…In particular, there is a lack of studies in the literature investigating the effect of light therapy by Light-emitting diode (LED) on the treatment of lung disorders. LED is a non-coherent and non-collimed light source that is suggested for healing on several tissues by the National Aeronautics and Space Administration (NASA) [16]. Various studies have demonstrated that LED presents good results for those diseases that are characterized by inflammation [17,18].…”