Melatonin - a Review on the Lesser Known Potential Nutraceutical

Melatonin, a pineal hormone is known to regulate rhythmic behavior of mammals. Its ubiquitous presence, established recently has brought into focus several health-promoting benefits of this molecule. However, till date, melatonin has been less utilized from its nutraceutical and functional point of view. This paper reviews the chemistry, chemical synthesis, metabolism of melatonin; its sources including its bioavailability from the same, its role in mammals and in plants and the analytical techniques for quantitative analysis of the same. The nutraceutical potential of melatonin and its functional properties have been elaborated. Melatonin’s function as a direct free radical scavenger endows it the potency to act as strong antioxidantsa property which needs to be further researched upon to establish its efficacy in food applications. INTRODUCTION: It was observed that the extract from beef pineal gland could lighten frog’s skin by reversing the darkening effect of melanocyte stimulating hormone and the compound responsible for this effect was named as ‘melatonin’ since it caused aggregation of melanin granules . Later the chemical structure of melatonin was elucidated as N-acetyl-5-methoxy tryptamine. Melatonin is one of the major hormones secreted by pineal gland and is called active pineal factor. It is 100 times active as adrenaline and noradrenaline, 200 times active as triiodothyronine, and 5000 times as active as serotonin in preventing darkening of frog skin by contracting melanophores . This discovery of melatonin led to further proliferation of research on pineal gland and its products. Pineal gland is an unpaired pine cone shaped organ with extensive vascularization and is reported to coordinate the psychophysiological functions in mammals. The functions of pineal gland can be directly related and implicated to its hormone-melatonin, which faithfully reflects pineal activity . The functions of melatonin and its basic physiology and pathophysiology in mammals are well studied and established. The recent discovery of melatonin in different structures of higher plants and also in lower phyla including algae and bacteria established the ubiquitous presence of this molecule and its role in cocoordinating certain basic events of life. Melatonin has strong immune-enhancing and antioxidative functions and plays significant role in neurological and physiological health. Melatonin with its nutraceutical potency could find possible application as antioxidant in foods. This paper reviews the chemistry, metabolism, sources of melatonin, its biosynthesis and its beneficial functions in the human system with special emphasis to its nutraceutical properties.