Melatonin (God gift for Upcoming generations).
The most of us have the disease of nowadays *Insomnia * because of all stress factors we exposed to it in our difficult world. Simply, Darkness triggers the body to make more melatonin, which signals the body to sleep. Light decreases melatonin production and signals the body to be awake.
Some people who have trouble sleeping have low levels of melatonin. It's thought that adding melatonin from supplements might help them sleep.
That’s all what we know about Melatonin benefits, But now we researched on its important role in preserving our next generations from all types of diseases.
- What is Melatonin ?
Melatonin (N-acetyl-5-methoxytryptamine) ''MLT'', which was discovered about 50 years ago, is an endogenous compound has been identified in a wide variety of organisms including bacteria, unicellular eukaryotes and different plants, as well as in a large number of animals (Maitra et al., 2015).
It is synthesized in various organs such as the pineal gland, retina, intestine, bone marrow cells, and skin. The circulating levels of the MLT vary in a daily cycle (Paredes et al., 2009).
Recent studies reveal that MLT is present in different tissues and organs such as harderian gland, extra-orbital lacrimal gland, retina, gastrointestinal (GI) tract and in bile in human and many vertebrates (Maitra et al., 2015).
The rhythm of MLT synthesis is generated by interacting networks of circadian clock genes located in the suprachiasmatic nucleus (SCN) of the hypothalamic part of brain. SCN is considered as the major central rhythm generating system or "clock” in mammals. The SCN clock is set to a 24-hour day by the natural light-dark cycle via retinal light input which then sends circadian signals over a neural pathway that project from the superior cervical ganglia (SCG) to the pineal and thereby driving rhythmic MLT synthesis. Specifically, SCN is the major regulatory site of the activity of AA-NAT, which is the penultimate and key enzyme in the synthesis of MLT from tryptophan (Chowdhury and Maitra et al., 2012).
Due to its high lipophilicity, the endogenous MLT levels are 3 to 10 times higher in the brain than in the serum and there is even a possibility that the brain tissue itself is capable of selective uptake. (Pang and Brown et al., 1983).
The pineal gland can only store MLT for a short time and the half-life of this hormone is 30 to 53 minutes (Aldhous et al., 1985).
It is metabolized in the liver to its hydroxylated 6 sulfatoxymelatonin form which is then excreted in the urine. The neurotransmitter norepinephrine is primarily responsible for initiating the production of this hormone through the adrenergic receptors of the pinealocytes, (Ebadi and Govitrapong, 1986).
- How Melatonin work in our bodies !
Melatonin is an indoleamine found to have numerous important physiological functions, acting as an antioxidant, anti-inflammatory, anti-carcinogenic, sleep inducer and regulator of the circadian rhythm in the body (Reiter et al., 2014).
MLT is a more potent antioxidant than vitamins C and E as the antioxidant effects of MLT include both direct and indirect effects with equal efficiency in multiple sites (nucleus, cytosol, and membranes) of the cell. It detoxifies a variety of free radicals and reactivates oxygen intermediates including the hydroxyl radical / hydrogen peroxide, peroxy radicals, peroxynitrite anion, singlet oxygen, nitric oxide and lipid peroxidation (Tan et al., 1993; Piechota et al., 2010 and Reiter et al., 2013).
There are many reports clarified that MLT has epigenetic property (Korkmaz and Reiter, 2008; Tain et al., 2014 and Wu et al., 2014). Epigenetics refers to alterations in gene expression that are not explained by changes in DNA sequence. DNA methylation, histone modification and RNA interference play central roles in epigenetic regulation (Bird et al., 2007).
Previous reports showed that MLT can inhibit DNA methyltransferases (DNMT) or act like a histone deacetylase (HDAC) inhibitor (Korkmaz and Reiter, 2008 and Wu et al., 2014). Given that epigenetic changes due to early-life insults predispose the offspring to develop a variety of diseases later in life and, thus, MLT may act as an epigenetic regulator to reprogram the process and prevent the development of adult disease.
Generally speaking,
MLT has many useful properties that might assist to elicit protective effects when administered during gestation period against many programmed diseases.
Dina M. M. H. EL-Kossi.
Lecturer at physiology department.
