Effects of low-level laser therapy (LLLT) on the nuclear factor (NF)-kappaB signaling pathway in traumatized muscle

Lasers Surg Med. 2006 Aug;38(7):704-13. doi: 10.1002/lsm.20371.


Background and objective: To investigate the effects of low-level laser therapy (LLLT) on nuclear factor kappa B (NF-kappaB) 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-kappaB and upregulation of iNOS expression, whereas protein concentration of I kappa B alpha 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-kappaB. The associated reduction of iNOS overexpression and collagen production suggest that the NF-kappaB pathway may be a signaling route involved in the pathogenesis of muscle trauma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arsenic
  • Collagen / analysis
  • Collagen / radiation effects
  • Disease Models, Animal
  • Gallium
  • Lasers
  • Low-Level Light Therapy* / instrumentation
  • Male
  • Muscle, Skeletal / injuries*
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / radiation effects
  • NF-kappa B / radiation effects*
  • Nitric Oxide Synthase Type II / radiation effects
  • Oxidative Stress / radiation effects
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species / radiation effects
  • Signal Transduction / radiation effects*
  • Time Factors
  • Up-Regulation / radiation effects
  • Wounds, Nonpenetrating / radiotherapy


  • NF-kappa B
  • Reactive Oxygen Species
  • Collagen
  • Gallium
  • Nitric Oxide Synthase Type II
  • Arsenic