Melatonin is a solid, lipophilic, hydro-phobic substance, also known as N-acetyl-5-methoxytryptamine. It is the principal hormone of the human pineal gland and can also be found at much lower concentrations in plants. Melatonin is synthesized by the pinealocytes of the pineal gland. The pathway begins with the amino acid L-tryptophan, which is metabolized to 5-hydroxy-tryptophan (5-HTP), then 5-hydroxy-tryptamine (sero-tonin) and finally to melatonin. The rate limiting step in the synthesis of melatonin is the N-acetylation of 5-hydroxy-tryptamine by the enzyme arylalkylamine N-acetyltransferase (AA-NAT).
Melatonin is the primary substance that controls entrainment in circadian rhythms, or patterns of wakefulness and sleep. The pineal is a tiny gland located deep in the brain behind the eyes, which monitors the external environment, integrating this information with the internal environment and producing melatonin to regulate the daily cycle. The pineal has nerves that connect it with the retina of the eye and the primary melatonin receptor is expressed mainly in the retina. The external stimuli of light and darkness cause the pineal to change the rhythm of the enzyme AA-NAT, which then affects melatonin levels. Through this mechanism, melatonin synthesis is stimulated by darkness and inhibited by light. The pineal gland also maintains continual homeostatic control and adjustment over factors such as body temperature, acidity-alkalinity, energy balance, tissue replacement and antioxidant defenses, in synchrony with the body's clocks.
Numerous studies suggest that melatonin can support regulation of sleep, in people of all ages. Melatonin has been used for jet lag and by night shift workers and the blind. Studies with menopausal women show melatonin offers benefits for sleep and mood and potential to support the immune response. At high doses, melatonin has significant antioxidant activity, including the capacity to inhibit metal ion-catalyzed oxidation processes, specifically the Fenton reaction. Aspirin, other NSAIDs and beta-blockers may lead to decreased melatonin levels. Health Functions:
The Possible Benefits of Melatonin, a Dietary Supplement:
Supports the aspects of brain chemistry involved in sleep.
May provide antioxidant activity. Ingredients:
Formula (#71660) Each capsule contains:
Servings Per Container: 100.
Amount Per Serving:Melatonin 1.3 mg.
Other ingredients: Cellulose, magnesium stearate. Servings:
As a dietary supplement, 1 or 2 capsules one hour before bedtime, or as directed by a healthcare practitioner. Caution:
Keep out of reach of children. Best refrigerated or stored in a cool place.
WARNING: Melatonin may have a strong sedating effect within 20 minutes of consumption. In rare cases it may affect seasonal affective disorder, depression or have stimulatory effects. Not to be used during the day time. Generally for use at bedtime. Not recommended for children or adolescents, for long-term administration, or for those with a prior history of seizures. Do not use while operating a motor vehicle or other machinery. Disclaimer:
The Food and Drug Administration has not evaluated statements contained herein. These products are not intended to diagnose, treat and cure or prevent disease. Always consult with your professional health care provider before changing any medication.