• S Chaudray, J Zipperle, A Islam, M Nimmervoll, L Karner, H Redl, S Bahrami, and P Dungel.
• Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria.
• Shock. 2015 Oct 1;44 Suppl 2:11.

IntroductionLow-level light therapy (LLLT) is clinically used to attenuate inflammation and improve tissue repair processes. We aimed to evaluate the effects of red LED light on inflammatory response in a whole blood in vitro model as well as in isolated granulocytes.MethodsHuman whole blood was stimulated with 1ng/ml LPS for 4 h. Pulsed LED light (632 nm) was applied either 1 h or 4 h after LPS for 10 min. Granulocytes were stimulated with PMA or fMLP respectively, and treated with LED-light likewise.ResultsLPS stimulation led to a significant up-regulation of pro-inflammatory cytokines TNF-α, IL-10, IL-6 and IL-8 analysed by multiplex assay. Leukotriene B4 and prostaglandine E2 were also elevated by LPS. Oxidative stress in the form of TBARS formation could not be confirmed in this model. However, LED treatment had no effect on these parameters, regardless of the time point of application. In isolated granulocytes light treatment had no stimulatory effect per se and did not reduce PMA-induced CD11b levels. Several studies show the efficacy of LLLT to reduce inflammation, e.g. in tendinopathies.ConclusionOur data suggest that the beneficial effects do not depend on the direct impact on leukocytes and their secretion of pro-inflammatory mediators. Also, our data disprove the hypothesis that LLLT can render some pro-inflammatory mediators harmless. Thus, more research studies are needed to understand the molecular mechanisms of LLLT and to standardize the clinical dosing and delivery protocols for light therapy to ensure the maximum efficacy and safety of photo-biomodulation.

17 keywords...

hide…