LED THERAPY IN SKIN REPAIR MODULATES CYTOKINE LEVELS AND OXIDATIVE STRESS

Abstract

<h3>Objectives</h3> To evaluate the effect of light emitting diode (LED) therapy in skin wound healing. <h3>Study Design</h3> 55 male Wistar rats were divided into 3 groups: negative control (<i>n</i> = 5; with no injury and without treatment), sham (with injury and without treatment), and LED groups. One full-thickness dorsal skin wound was created. The LED group received daily treatment. After 3, 5, 10, 14, and 21 days, euthanasia was performed for clinical, morphologic, oxidative stress (erythrocyte lipid peroxidation products (MDA), antioxidant enzymes superoxide dismutase (SOD) and glutathione (GSH)), and cytokine analyses (IL-1β, IL-10, and tumor necrosis factor alpha [TNF-α]). <h3>Results</h3> Clinically, at day 10, the LED therapy promoted faster tissue repair than the sham group (<i>P</i> < .05). Histopathologic evaluations showed that in 3 and 10 days, the LED group exhibited more advanced resolution of inflammatory processes compared to the sham group. MDA was lower and GSH was higher in the LED group in all experimental periods. SOD was higher at 10 days and lower at 5 and 21 days (<i>P</i> < .01). On day 10 there was a significant difference in the levels of IL-1β, IL-10 (<i>P</i> < .05), and TNF-α (<i>P</i> < .01). <h3>Conclusions</h3> LED therapy has antioxidant action and modulates inflammatory cytokines but had limited clinical results with the parameters used.