Melatonin as a marker of free radicals

There is no elixir of eternal youth, but nowadays if there is a substance that approaches, that is melatonin.

The first indications of the existence of this substance were in 1917, and in 1958 it was isolated for the first time. Its importance has not been recognized until relatively recently. Today it is widely known for its ability to regulate the circadian rhythm, but the most important quality is the antioxidant capacity at mitochondrial level, associated with its low toxicity.

These spectacular effects of melatonin on mitochondrial function have not been achieved with any other antioxidant, including vitamins C and E, or N-acetylcysteine, even using them at concentrations 10,000 times bigger than melatonin.

It is known that melatonin is secreted in animals by the pineal gland and is also synthesized in other tissues such as the intestinal tract, the skin and the bone marrow. It is also known that this substance decreases during aging.

After oral administration, the maximum level in the plasma is reached between 20 and 30 min. This concentration is maintained for about 90 min and then declines rapidly with a half-life between 40 and 50 min.

When we take exogenous antioxidants (vitamins and similar) we are able to stop the endogenous defense systems of the organism and cause a hyper-reduced state, which is the optimal environment for the development of cancer. Free radicals damage the cells, but they are also important molecules of cellular regulation. That is why we should never exaggeratedly reduce said radicals. On the contrary, if we take melatonin, which is a hormone that our body produces, it regulates the endogenous defense systems, adapting them to the needs of the organism at each moment.

Therefore, melatonin supplementation favors the body’s defense capacity under all circumstances, without selecting only the free radicals, maintaining the organism in the state of oxidative equilibrium, that is, an adequate balance between the levels of free radicals and Antioxidant systems.

The Melatonin is metabolized in the mitochondria and cytochrome P450 of the hepatocyte and excreted in the urine as 6-Hydroxymelatonin conjugated with glucuronic acid. Also 3-hydroxymelatonin, the final product of the chemical via (antioxidant cascade), is excreted in the urine and it can become in a marker of generation of free radicals.

Francisco Cremades

Technical Director and Quality Control Manager

R&D, Process Development and Scale-up


Referencias bibliográficas:

Revista CENIC. Ciencias Biológicas, vol. 43, núm. 3, septiembre-diciembre, 2012

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Lerner AB, Case JD, Takahashi Y. Isolation of melatonin and 5-methoxyindole-3-acetic acid from bovine pineal glands. The Journal of Biological Chemistry 1960;235: 1992-7.

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