Capsaicin exhibits neuroprotective effects in a model of transient global cerebral ischemia in Mongolian gerbils

Br J Pharmacol. 2005 Mar;144(5):727-35. doi: 10.1038/sj.bjp.0706115.

Abstract

1. Capsaicin, the irritant principle of hot peppers, is a vanilloid agonist known to activate the transient receptor potential channel vanilloid subfamily member 1 (VR1), recently reported to be involved in neurodegeneration. The present study investigated the role of VR1 in a model of global cerebral ischemia in gerbils. 2. Over the dose range tested, capsaicin (0.01, 0.025, 0.05, 0.2 and 0.6 mg kg(-1)), given 5 min after recirculation, dose-dependently antagonized the ischemia-induced electroencephalographic total spectral power decrease and restored relative frequency band distribution evaluated 7 days after ischemia. 3. Capsaicin, at all tested doses, fully prevented ischemia-induced hyperlocomotion evaluated 1 day after ischemia. 4. Capsaicin dose-dependently antagonized ischemia-induced memory impairment evaluated in a passive avoidance task, 3 days after ischemia. 5. Capsaicin showed a dose-dependent hypothermic effect evaluated for 2 h after recirculation. 6. At 7 days after ischemia, a progressive survival of pyramidal cells in the CA1 subfield in capsaicin-treated gerbils, with a maximum of 80%, at a dose of 0.2 mg kg(-1), was obtained. 7. The selective VR1 antagonist, capsazepine (0.01 mg kg(-1)), reversed capsaicin-induced protective effects, in a competitive manner. 8. These results suggest that the neuroprotective effect of capsaicin may be attributable, at least in part, to VR1 desensitization and provide a valuable target for development of interventional pharmacological strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Capsaicin / analogs & derivatives
  • Capsaicin / pharmacology*
  • Cell Survival / drug effects
  • Disease Models, Animal
  • Electroencephalography
  • Gerbillinae
  • Hippocampus / drug effects
  • Hippocampus / pathology
  • Ischemic Attack, Transient / drug therapy*
  • Male
  • Memory / drug effects
  • Motor Activity / drug effects
  • Neuroprotective Agents / pharmacology*
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / pathology
  • Receptors, Drug / agonists
  • Receptors, Drug / antagonists & inhibitors

Substances

  • Neuroprotective Agents
  • Receptors, Drug
  • capsazepine
  • Capsaicin