Melatonin: A Novel Indolamine in Oral Health and Disease

Abstract

This paper attempts to summarise the findings accumulated within the last few years concerning the hormone of darkness “melatonin.” Based on its origin, from the pineal gland until recently it was portrayed exclusively as a hormone. Due to its lipophilic nature, it is accessible to every cell. Thus, in the classic sense it is a cell protector rather than a hormone. Recent studies, by Claustrat et al. (2005), detected few extrapineal sources of melatonin like retina, gastrointestinal tract, and salivary glands. Due to these sources, research by Cutando et al. (2007), is trying to explore the implications of melatonin in the oral cavity, in addition to its physiologic anti-oxidant, immunomodulatory and oncostatic functions at systemic level that may be receptor dependent or independent. Recently, certain in vivo studies by Shimozuma et al. (2011), detected the secretion of melatonin from salivary glands further emphasising its local activity. Thus, within our confines the effects of melatonin in the mouth are reviewed, adding a note on therapeutic potentials of melatonin both systemically and orally.

The Risk of Night Shift Workers to the Glucose Blood Levels, Saliva, and Dental Caries

“…15 Then β-adrenergic receptors are not activated so that there is a decrease in melatonin secretion. 16 The decrease in melatonin secretion causes a decrease in antioxidants resulting more production of reactive oxygen species (ROS), 17 which is in body fluids and saliva. Increased ROS forms oxidative stress that is followed by an increase in malondialdehyde (MDA), which continues to create imbalance in the body and affect disease progression.…”

Melatonin localization in human salivary glands

“…Melatonin (N‐acetyl‐5‐methoxytryptamine) is principally produced by pinealocytes, but its synthesis occurs in other tissues also . According to the classical theory, melatonin is released by pineal gland into the blood circulation and, due to its lipophilic nature, crosses the cell membranes, enters the cells, and becomes a natural component of several body fluids, such as milk, urine and saliva . However, there is an increasing evidence that passive diffusion is not the only possible way for melatonin transport and that some tissues have a still unknown intracellular machinery that regulates the melatonin movement .…”

Subcellular distribution of melatonin receptors in human parotid glands

“…With respect to the gastrointestinal tract, systemic effects may be expected, as it is released into the blood stream in response to food intake (Bubenik, 2002(Bubenik, , 2008. Due to its unique lipophilic nature (Hardeland et al 2011;Chava & Sirisha, 2012), circulating melatonin crosses the cell membranes and distributes easily into tissues and biological fluids; it occurs in milk (Cohen Engler et al 2012), bile (Messner et al 2001), cerebrospinal fluid (Tan et al 2010), urine and saliva (Vakkuri, 1985;de Almeida et al 2011;Almughrabi et al 2012).…”