Trans-caryophyllene suppresses hypoxia-induced neuroinflammatory responses by inhibiting NF-κB activation in microglia

J Mol Neurosci. 2014 Sep;54(1):41-8. doi: 10.1007/s12031-014-0243-5. Epub 2014 Feb 4.

Abstract

Microglia cells have been reported to mediate hypoxia-induced inflammation through the production of proinflammatory cytokines, including interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and IL-6. Given the fact that the activation of the type 2 cannabinoid receptor (CB2R) provides antioxidative and anti-inflammatory results, it is suspected that its selective agonist, trans-caryophyllene (TC), may have protective effects against hypoxia-induced neuroinflammatory responses. In this study, TC was found to significantly inhibit hypoxia-induced cytotoxicity as well as the release of proinflammatory cytokines, including IL-1β, TNF-α, and IL-6, through activation of BV2 microglia following hypoxic exposure (1 % O2, 24 h). Furthermore, TC significantly inhibited hypoxia-induced generation of reactive oxygen species (ROS) in mitochondria as well as the activation of nuclear factor kappa B (NF-κB) in microglia. Importantly, TC's effects on inhibiting the activation of NF-κB and the secretion of inflammatory cytokines can be abolished by muting the CB2R using small RNA interference. These observations indicate that TC suppresses the hypoxia-induced neuroinflammatory response through inhibition of NF-κB activation in microglia. Therefore, TC may be beneficial in preventing hypoxia-induced neuroinflammation.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Cell Hypoxia
  • Cell Line
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Mice
  • Microglia / drug effects*
  • Microglia / metabolism
  • Mitochondria / genetics
  • Mitochondria / metabolism
  • NF-kappa B / genetics
  • NF-kappa B / metabolism*
  • Polycyclic Sesquiterpenes
  • Reactive Oxygen Species / metabolism
  • Receptor, Cannabinoid, CB2 / antagonists & inhibitors
  • Receptor, Cannabinoid, CB2 / genetics
  • Receptor, Cannabinoid, CB2 / metabolism
  • Sesquiterpenes / pharmacology*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Interleukin-1beta
  • Interleukin-6
  • NF-kappa B
  • Polycyclic Sesquiterpenes
  • Reactive Oxygen Species
  • Receptor, Cannabinoid, CB2
  • Sesquiterpenes
  • Tumor Necrosis Factor-alpha
  • caryophyllene