Title:Melatonin in Antinociception: Its Therapeutic Applications
Volume: 10
Issue: 2
Author(s): Venkatramanujam Srinivasan, Edward C. Lauterbach, Khek Yu Ho, Dario Acuna-Castroviejo, Rahimah Zakaria and Amnon Brzezinski
Affiliation:
Keywords:
Pain, nociception, analgesia, melatonin, inflammatory, neuropathic, fibromyalgia, cluster headache, migraine
Abstract: The intensity of pain sensation exhibits marked day and night variations. Since the intensity of pain perception
is low during dark hours of the night when melatonin levels are high, this hormone has been implicated as one of the
prime antinociceptive substances. A number of studies have examined the antinociceptive role of melatonin in acute,
inflammatory and neuropathic pain animal models. It has been demonstrated that melatonin exerts antinociceptive actions
by acting at both spinal cord and supraspinal levels. The mechanism of antinociceptive actions of melatonin involves
opioid, benzodiazepine, α1- and α2-adrenergic, serotonergic and cholinergic receptors. Most importantly however, the
involvement of MT1/MT2 melatonergic receptors in the spinal cord has been well documented as an antinociceptive
mechanism in a number of animal models of pain perception. Exogenous melatonin has been used effectively in the
management of pain in medical conditions such as fibromyalgia, irritable bowel syndrome and migraine and cluster
headache. Melatonin has been tried during surgical operating conditions and has been shown to enhance both preoperative
and post-operative analgesia. The present review discusses the available evidence indicating that melatonin, acting
through MT1/MT2 melatonin receptors, plays an important role in the pathophysiological mechanism of pain.
