Pharmacological activation of heme oxygenase (HO)-1/carbon monoxide pathway prevents the development of peripheral neuropathic pain in Wistar rats

Naunyn Schmiedebergs Arch Pharmacol. 2013 Jan;386(1):79-90. doi: 10.1007/s00210-012-0816-1. Epub 2012 Dec 9.

Abstract

Recent studies have emphasized the contribution of neuroinflammation and oxido-nitrosative stress to neuropathic pain. Both, heme oxygenase (HO)-1 and carbon monoxide (CO) play an important role in regulating free radical generation and inflammation. Herein, we investigated the role of HO-1/CO pathway, by using hemin, a selective HO activator, and CO-releasing molecule (CORM)-2, a CO-releasing agent, in rat sciatic nerve chronic constriction injury (CCI)-induced neuropathic pain. CCI rats exhibited full development of behavioral hypersensitivity symptoms, including cold allodynia, mechanical and thermal hyperalgesia and also exhibit of a significant increase in spinal cord pro-inflammatory cytokines (TNF-α and IL-1β) and oxido-nitrosative stress markers, both in spinal cord and ipsilateral sciatic nerve homogenate. Spinal (10 and 30 μg/rat, intrathecal (i.t.)), but not systemic (5 and 10 mg/kg, subcutaneous (s.c.)), administration of hemin for 14 days significantly prevented the development of behavioral hypersensitivity. Further, simultaneous administration of hemin via spinal (10 μg/rat, i.t.) and systemic (5 mg/kg, s.c.) routes led to a more pronounced inhibition of the development of behavioral hypersensitivity. Further, administration of CORM-2 (1 and 5 mg/kg, s.c.), dose-dependently and most effectively, prevented the development of behavioral hypersensitivity. Both hemin and CORM-2 produced ameliorative beneficial effects that paralleled with the extent of reduction of oxido-nitrosative stress and pro-inflammatory cytokines. Also, hemin and CORM-2 significantly improved the levels of HO-1 and activity of anti-oxidant enzymes such as superoxide dismutase and catalase. Thus, it may be concluded that chronic pharmacological activation of HO-1/CO pathway may prevent the development of behavioral symptoms of neuropathic pain, through an activation of anti-inflammatory and anti-oxidant mechanisms.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism
  • Carbon Monoxide / metabolism*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Female
  • Heme Oxygenase-1 / metabolism*
  • Hemin / administration & dosage
  • Hemin / pharmacology*
  • Inflammation / drug therapy
  • Inflammation / pathology
  • Injections, Spinal
  • Injections, Subcutaneous
  • Interleukin-1beta / metabolism
  • Male
  • Organometallic Compounds / administration & dosage
  • Organometallic Compounds / pharmacology*
  • Oxidative Stress / drug effects
  • Peripheral Nervous System Diseases / prevention & control*
  • Rats
  • Rats, Wistar
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Antioxidants
  • Interleukin-1beta
  • Organometallic Compounds
  • Tumor Necrosis Factor-alpha
  • tricarbonyldichlororuthenium (II) dimer
  • Hemin
  • Carbon Monoxide
  • Heme Oxygenase-1