Related topics: sleep

Agronomists save tomatoes from toxic aluminum with melatonin

RUDN University agronomists and colleagues from China and Iran have helped tomatoes cope with the toxic effect of aluminum in acidic soils with the help of melatonin. This hormone contributes to nitric oxide production, blocking ...

Commercial-scale biomanufactured melatonin is here

For the first time, large amounts of melatonin are being made by bacteria. In industrial sized fermentation vats, harmless strains of engineered E. coli bacteria are feeding on glucose and churning out melatonin, the hormone ...

Do urban fish exhibit impaired sleep?

Melatonin controls the body clock—high melatonin levels make us feel tired in the evening. However, the hormone also plays an important role in animals' biological rhythms. Artificial light at night—light pollution—can ...

Shining new light on the pineal gland

When zebrafish lack a specific protein, the two hemispheres of the brain develop symmetrically, and the sleep hormone melatonin is not produced. These results were recently published by Freiburg biologists Theresa Schredelseker ...

Video: Does melatonin do anything?

Melatonin is a widely used supplement. Many people turn to the hormone hoping it will improve their sleep, but do claims of its efficacy have any merit?

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Melatonin

Melatonin i/ˌmɛləˈtoʊnɪn/, also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes. In animals, circulating levels of the hormone melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions.

Many biological effects of melatonin are produced through activation of melatonin receptors, while others are due to its role as a pervasive and powerful antioxidant, with a particular role in the protection of nuclear and mitochondrial DNA.

In mammals, melatonin is secreted into the blood by the pineal gland in the brain. Known as the "hormone of darkness," it is secreted in darkness in both day-active (diurnal) and night-active (nocturnal) animals.

It may also be produced by a variety of peripheral cells such as bone marrow cells, lymphocytes, and epithelial cells. Usually, the melatonin concentration in these cells is much higher than that found in the blood, but it does not seem to be regulated by the photoperiod.

Research has shown that when bird chicks ingest melatonin-rich plant feed, such as rice, the melatonin binds to melatonin receptors in their brains. No food has been found to elevate plasma melatonin levels in humans.

Products containing melatonin have been available over-the-counter as dietary supplements in the United States since the mid-1990s. In many other countries, the over-the-counter sale of this neurohormone is not permitted or requires a prescription, and the U.S. Postal Service lists unapproved melatonin preparations among items prohibited by Germany.

This text uses material from Wikipedia, licensed under CC BY-SA