Melatonin: pharmacological aspects and clinical trends.
Melatonin, N-acetyl-5-methoxytryptamine, the major hormone produced by the pineal gland under the influence of the dark/light cycle, has been shown to have a large number of therapeutic possibilities. It has been utilized in several countries for circadian rhythm disorders, sleep disturbances, jet lag, and sleep-wake cycle disturbances in blind people, and shift workers. In our mechanism of act, the G(i) protein-coupled metabotropic melatonin receptors MT1 and MT2 are the primary mediators of the physiological actions of melatonin. This hormone plays an important role in the regulation of physiological and neuroendocrine functions, such as synchronization of seasonal reproductive rhythms and entrainment of circadian cycles. In addition to its chronobiological role, several pharmacological effects of melatonin have been reported in mammals including sedative, antioxidant, anxiolytic, antidepressant, anticonvulsant, and analgesic activities. There is some evidence from clinical trials that melatonin can be helpful in that event. Current trends of pharmacological functions of melatonin pointed out its use in the treatment of neurodegenerative and neoplastic diseases. These effects and uses of melatonin are mentioned but further confirmatory studies are needed in most of them.
Rios
Emiliano Ricardo Vasconcelos
ER
Laboratory of Neuropharmacology, Federal University of Ceará, Fortaleza, Brazil. emilianovasconcelos@yahoo.com.br
Venâncio
Edith Teles
ET
Rocha
Nayrton Flávio Moura
NF
Woods
David John
DJ
Vasconcelos
Silvania
S
Macedo
Danielle
D
Sousa
Francisca Cléa Florenço de
FC
Fonteles
Marta Maria de França
MM
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism; D003863:Depression / Q000188:drug therapy; D016166:Free Radical Scavengers; D006801:Humans; D007192:Indenes; D020179:Jet Lag Syndrome / Q000178:diet therapy; D008550:Melatonin / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use*; D044094:Receptors, Melatonin / Q000378:metabolism; D012890:Sleep / Q000502:physiology; D020178:Sleep Disorders, Circadian Rhythm / Q000188:drug therapy*
D000928:Antidepressive Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D007192:Indenes; D044094:Receptors, Melatonin; C495910:ramelteon; D008550:Melatonin