Effect of NIR laser therapy by MLS-MiS source against neuropathic pain in rats: in vivo and ex vivo analysis

Sci Rep. 2019 Jun 26;9(1):9297. doi: 10.1038/s41598-019-45469-5.

Abstract

Neuropathic pain is characterized by an uncertain etiology and by a poor response to common therapies. The ineffectiveness and the frequent side effects of the drugs used to counteract neuropathic pain call for the discovery of new therapeutic strategies. Laser therapy proved to be effective for reducing pain sensitivity thus improving the quality of life. However, its application parameters and efficacy in chronic pain must be further analyzed. We investigated the pain relieving and protective effect of Photobiomodulation Therapy in a rat model of compressive mononeuropathy induced by Chronic Constriction Injury of the sciatic nerve (CCI). Laser (MLS-MiS) applications started 7 days after surgery and were performed ten times over a three week period showing a reduction in mechanical hypersensitivity and spontaneous pain that started from the first laser treatment until the end of the experiment. The ex vivo analysis highlighted the protective role of laser through the myelin sheath recovery in the sciatic nerve, inhibition of iNOS expression and enhancement of EAAT-2 levels in the spinal cord. In conclusion, this study supports laser treatment as a future therapeutic strategy in patients suffering from neuropathic pain induced by trauma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Excitatory Amino Acid Transporter 2 / metabolism
  • Hyperalgesia / complications
  • Inflammation
  • Lasers*
  • Low-Level Light Therapy / methods*
  • Male
  • Myelin Basic Protein / metabolism
  • Myelin Sheath / radiation effects*
  • Neuralgia / radiotherapy*
  • Nitric Oxide Synthase Type II / antagonists & inhibitors
  • Pain Threshold
  • Pressure
  • Quality of Life
  • Rats
  • Rats, Sprague-Dawley
  • Sciatic Nerve / injuries
  • Spinal Cord / radiation effects

Substances

  • Excitatory Amino Acid Transporter 2
  • Myelin Basic Protein
  • Slc1a2 protein, rat
  • Nitric Oxide Synthase Type II
  • Nos2 protein, rat