Low-Level Laser Therapy and Sodium Diclofenac in Acute Inflammatory Response Induced by Skeletal Muscle Trauma: Effects in Muscle Morphology and mRNA Gene Expression of Inflammatory Markers

Pharmacological therapy is widely used in the treatment of muscle injuries. On the other hand, low-level laser therapy (LLLT) arises as a promising nonpharmacological treatment. The aim of this study was to analyze the effects of sodium diclofenac (topical application) and LLLT on morphological aspects and gene expression of biochemical inflammatory markers. We performed a single trauma in tibialis anterior muscle of rats. After 1h, animals were treated with sodium diclofenac (11.6mg g-1 of solution) or LLLT (810nm; continuous mode; 100mW; 3.57Wcm2; 1, 3 or 9J; 10, 30 or 90s). Histological analysis and quantification of gene expression (real-time polymerase chain reactionRT-PCR) of cyclooxygenase 1 and 2 (COX-1 and COX-2) and tumor necrosis factor-alpha (TNF-) were performed at 6, 12 and 24h after trauma. LLLT with all doses improved morphological aspects of muscle tissue, showing better results than injury and diclofenac groups. All LLLT doses also decreased (P<0.05) COX-2 compared to injury group at all time points, and to diclofenac group at 24h after trauma. In addition, LLLT decreased (P<0.05) TNF- compared both to injury and diclofenac groups at all time points. LLLT mainly with dose of 9J is better than topical application of diclofenac in acute inflammation after muscle trauma.