Melatonin, a natural chemical compound that is circulated throughout the body of different organisms, plays a vital role in regulating the circadian rhythm or the sleep-wake cycle, particularly in humans. Melatonin is secreted by the pineal gland which is a gland just the size of the pea located at the center of the brain. The body produces a steady supply of melatonin but the supply eventually reduces when we get older thus the reduction of melatonin is often associated with the incidence of insomnia (Zhdanova et al., 2001). Aside from regulating the sleep patterns, melatonin also provides other functions.
Melatonin as Antioxidants
Aside from its function in regulating the biological clock, melatonin also has a powerful antioxidant property. Melatonin serves as an excellent antioxidant since it can cross cell membranes easily. Melatonin scavenges harmful substances or free radicals like OH, O2- and NO. These free radicals cause damage to the cells which can lead to aging of the body. Melatonin is also very stable and it does not undergo redox reactions unlike other antioxidants such as Vitamin C which promotes the formation of free radicals when it undergoes the redox reaction thereby making melatonin more effective than any other antioxidants.
At present, the experimental evidences that shows the effect of melatonin as a good antioxidant is evident on rats. Rats treated with a carcinogenic compound resulted to the increase of free radicals which damaged the nuclear DNA. However, when treated with melatonin, the amount of damage to the cells and DNA was reduced. As Claustrat (2005) noted, patients who have undergone hemodialysis also face oxidative stress due to the presence of iron and erythropoietin administered to treat anemia was prevented when melatonin was also administered together with the treatment of anemia. The anti-oxidative property of melatonin also gives melatonin its anti-aging benefits.
Melatonin as Immunity Booster and Improved Memory
Currently, there are a lot of evidences that show that the pineal gland and melatonin also modulates the responses of the immune system. Melatonin can react with specific binding sites in the membrane of the cells in the lymphatic systems. Moreover, the interaction between the pineal and the immune system is bidirectional, the fact that cytokines as well as interleukins (immune system molecules) also affect the synthesis of melatonin.
On the other hand, melatonin also helps in improving the memory of patients. In fact, in a study conducted by Rimmele et al. (2008), acute stress activates the production of cortisol (one of the basal stress hormones) levels which is the chemical that causes stress in the body. The administration of melatonin shows a reduction of the basal stress hormone. The basal stress hormones include norepinephrine, epinephrine aside from cortisone which influences the retrieval of memories. Thus the use of melatonin can also reduce the stress hormones which in turn result to better memory retention.
Melatonin as an Oncostatic Agent
The validity of melatonin as an oncostatic or cancer-preventing agent has been identified in different studies and the cancer-preventing function of melatonin is linked towards its antioxidative properties. Isolated reports have found out the melatonin administered at night tend to have more anti-cancer effects than melatonin administered at daytime (Claustrat, 2005).
Melatonin as a Hair Growth Promoter
Melatonin is also known to modulate the growth of hair. This is well documented on animals like sheep and other animals that produce fur. Moreover, melatonin has also been known to affect the molting as well as the coat color of animal species. In the study conducted by Fischer et al. (2008), they have found out that the human scalp has a local immune-reactivity towards melatonin and this is limited to the few layers of the epidermis as well as in the hair shaft. The result of this study is very promising since melatonin can be used to treat hair problems like patterned baldness and hair thinning.
Melatonin As A Drug
Melatonin shows promising use and this is the reason why a lot of reasons why there are a lot of melatonin drugs that are out in the market recently. Melatonin pills are available in two forms such as the natural and synthetic pulls. Natural melatonin is extracted from the pineal glands of animals while synthetic melatonin is formulated inside the laboratory.
The purity of melatonin varies depending on the type of pills is sold. Natural melatonin, while you can be assured that it originated from natural sources, may be contaminated with virus or prions or heat-resistant proteins that may cause threat to the one taking the pill. On the other hand, synthetic melatonin pills are made in the laboratory thus you can be assured of its purity. Now whether there is a difference between the efficacy between natural and synthetic melatonin pills, research is still underway regarding this matter.
How Melatonin Pills Work
Melatonin pills mimic the effect of natural melatonin found in the body. In fact, it promotes the production of plasma melatonin around 8pm to 8am thus melatonin is best administered during nighttime or prior to sleep.
Recent studies have shown that Melatonin is effective if you take in ? to 5 milligrams of it daily. One study conducted by the Massachusetts Institute of Technology noted that melatonin pills contain three or ten times the amount needed by the body to assist in the normal physiological functions. Moreover, the study also noted that huge amounts of melatonin can also be counterproductive (Lewy et al., 1987) He also noted that the excess melatonin can spill to other zones and will be excreted through the urine as well as in the saliva.
Side Effects of Melatonin Pills
Melatonin has few side effects, which include excessive drowsiness, morning grogginess and headaches. These side effects usually take about one or two weeks before it disappears. The side effects can also be lowered by reducing the dosage of melatonin intake.
Caution When Taking Melatonin Pills
Pregnant and nursing women are discouraged to take this pill although there has not been any trials conducted about the effect of excessive exposure of infants to this hormone. Moreover, people who are auto-immune compromised are discouraged from taking this pill since the change in the level of this hormone can exacerbate immunomodulation for patients who suffer auto-immune diseases. On the other hand, there has been no study conducted regarding the long term effects of taking melatonin pills.
Although melatonin has been discovered almost half a century ago, the data on the physiological role of melatonin is still few thus it is important that the knowledge that we know now should be reinforced. The thing here is that melatonin can play a very big role as a universal endogenous synchronizer that does not only affect our sleep-wake cycle but also our mood and other important physiological functions of the different organs of the body.
Claustrat, B., J. Brun and G. Chazo. 2005. The Basic Physiology And Pathophysiology Of Melatonin. Sleep Medicine Reviews 9: 11–24.
Fischer, T.W., A. Slominski, D.J. Tobin and R. Paus. 2008. Melatonin And The Hair Follicle. Journal of Pineal Research 44:1–15.
Lewy, A., R. Sack, L. Miller and T. Hoban.1987. Antidepressant And Circadian Phase-shifting Effects Of Light". Science 235 (4786): 352–354.
Rimmele, U., M. Spillmann, C. B?rtschi, O.T. Wolf, C.S. Weber, U. Ehlert and P.H. Wirtz. 2008. Melatonin Improves Memory Acquisition Under Stress Independent of Stress Hormone Release. Psychopharmacology.
Rogers, N.L., D.F. Dinges, D.J. Kennaway and D. Dawson. 2003. Potential Action of Melatonin in Insomnia. SLEEP, 26 (8): 1058-1059.
Zhdanova, I.V., R.J. Wurtman, M.M. Regan, J.A. Taylor, J.P. Shi and O.U. Leclair. 2001. Melatonin Treatment for Age-Related Insomnia. The Journal of Clinical Endocrinology & Metabolism 86(10):4727–4730.