dinoprost and Neuralgia

Topics: Aminoquinolines; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Benzamides; Cyclooxygenase Inhibitors; Dinoprost; Dinoprostone; Humans; Narcotic Antagonists; Neuralgia; Nitric Oxide; Nociceptin; Nociceptin Receptor; Opioid Peptides; Receptors, N-Methyl-D-Aspartate; Receptors, Opioid; Spinal Cord

Neuropathic pain arising from peripheral nerve injury is a clinical disorder characterized by a combination of spontaneous pain, hyperalgesia and tactile pain (allodynia), and remains a significant clinical problem since it is often poorly relieved by conventional analgesics. To seek an analgesic compound(s) in Chinese herbs, we examined the effect of seven Chinese herbs that are routinely prescribed for pain management in two neuropathic pain models: allodynia induced by intrathecal administration of prostaglandin F2alpha (PGF2alpha) and by selective L5 spinal nerve transection. The extracts of Moutan cortex and Coicis semen dose-dependently alleviated the PGF2alpha-induced allodynia by oral administration 1 h before intrathecal injection of PGF2alpha. When orally administrated every day for 7 days, these extracts attenuated neuropathic pain in the ipsilateral side, but not in the contralateral side, day 7 after L5 spinal nerve transection. The increase in NADPH diaphorase activity in the spinal cord associated with neuropathic pain was also blocked by these extracts. These results suggest that Moutan cortex and Coicis semen contain substances effective in neuropathic pain.

Topics: Anesthesia; Animals; Dinoprost; Disease Models, Animal; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Male; Mice; NADPH Dehydrogenase; Neuralgia; Paeonia; Pain Measurement; Spinal Cord; Spinal Cord Injuries; Time Factors