title: Suppressive effects of intrathecal paeoniflorin on bee venom-induced pain-related behaviors and spinal neuronal activation.
abstract: Recently, paeoniflorin (PF) administered systemically was found to have analgesic effects against inflammatory pain and hypersensitivity in a naloxone-reversible manner. In the present study, we adopted intrathecal administration to evaluate whether PF has direct antinociceptive actions at the spinal level. Pain-related behaviors and spinal c-Fos expression were induced by subcutaneous injection of bee venom (BV) into one hind paw of a rat. Intrathecal pretreatment of PF resulted in an inhibition of the BV-induced persistent spontaneous nociception and partially suppressed the occurrence of both thermal and mechanical hypersensitivity. Moreover, the PF-produced antinociception was completely reversed by naloxone. We further evaluated the intrathecal effects of the drug on the BV-induced c-Fos expression. The result showed that intrathecal PF preconditioning was effective to suppress spinal c-Fos expression in both superficial (lamina I-II) and deep (lamina IV-VI) layers of the L(4-5) dorsal spine. This result showed that PF has a direct pharmacological action in the spinal cord dorsal horn via activation of opioid receptors.
authors.affiliation: Department of Emergency Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Hou-You
authors.initials: HY
authors.lastname: Yu
authors.forename: De-guang
authors.initials: DG
authors.lastname: Mu
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Wen
authors.initials: W
authors.lastname: Yin
mesh_terms: D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D001514:Bee Venoms; D001522:Behavior, Animal / Q000187:drug effects; D001565:Benzoates / Q000494:pharmacology / Q000627:therapeutic use*; D001952:Bridged-Ring Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D005960:Glucosides / Q000494:pharmacology / Q000627:therapeutic use*; D006358:Hot Temperature; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism; D007278:Injections, Spinal; D008297:Male; D039821:Monoterpenes; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D020671:Posterior Horn Cells / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014110:Touch; D006027:Glycosides
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001514:Bee Venoms; D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides; D039821:Monoterpenes; D009270:Naloxone; D009292:Narcotic Antagonists; D016760:Proto-Oncogene Proteins c-fos; C015423:peoniflorin; D006027:Glycosides