Efeitos da terapia laser de baixa potência (810 nm) e do diclofenaco sódico (uso tópico) sobre padrões bioquímicos e morfológicos na lesão muscular induzida por contusão no músculo tibial de rato

Abstract

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 1 h, animals were treated with sodium diclofenac (11.6 mg g-1 of solution) or LLLT (810 nm; continuous mode; 100 mW; 3.57W cm2 ; 1, 3 or 9 J; 10, 30 or 90 s). Histological analysis and quantification of gene expres-sion (real-time polymerase chain reaction RT-PCR) of cyclooxygenase 1 and 2 (COX-1 and COX-2) and tumor necrosis factor-alpha (TNF-α) were performed at 6, 12 and 24 h 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 24 h after trauma. In addition, LLLT decreased (P<0.05) TNF-α compared both to injury and diclofenac groups at all time points. LLLT mainly with dose of 9 J is better than topical application of diclofenac in acute inflammation after muscle trauma.