AbstractBackground and Objective:
To investigate the effects of low-level laser therapy (LLLT) on nuclear factor kappa B (NF-κB) activation and inducible nitric oxide synthase (iNOS) expression in an experimental model of muscle trauma.Study Design/Materials and Methods:
Injury to the gastrocnemius muscle in the rat was produced by a single impact blunt trauma. A low-level galium arsenide (Ga-As) laser (904 nm, 45 mW, and 5 J/cm2) was applied for 35 seconds duration, continuously.Results:
Histological abnormalities with increase in collagen concentration, and oxidative stress were observed after trauma. This was accompanied by activation of NF-κB and upregulation of iNOS expression, whereas protein concentration of IκBα decreased. These effects were blocked by LLLT.Conclusion:
LLLT reduced the inflammatory response induced by trauma and was able to block the effects of reactive oxygen species (ROS) release and the activation of NF-κB. The associated reduction of iNOS overexpression and collagen production suggest that the NF-κB pathway may be a signaling route involved in the pathogenesis of muscle trauma.