Melatonin as the Cornerstone of Neuroimmunoendocrinology

Abstract

Much attention has been recently drawn to studying melatonin – a hormone whose synthesis was first found in the epiphysis (pineal gland). This interest can be due to discovering the role of melatonin in numerous physiological processes. It was the discovery of melatonin synthesis in endocrine organs (pineal gland), neural structures (Purkinje cells in the cerebellum, retinal photoreceptors), and immunocompetent cells (T lymphocytes, NK cells, mast cells) that triggered the evolution of new approaches to the unifield signal regulation of homeostasis, which, at the turn of the 21st century, lead to the creation of a new integral biomedical discipline—neuroimmunoendocrinology. While numerous hormones have been verified over the last decade outside the “classical” locations of their formation, melatonin occupies an exclusive position with regard to the diversity of locations where it is synthesized and secreted. This review provides an overview and discussion of the major data regarding the role of melatonin in various physiological and pathological processes, which affords grounds for considering melatonin as the “cornerstone” on which neuroimmunoendocrinology has been built as an integral concept of homeostasis regulation.

Melatonin Suppresses Macrophage M1 Polarization and ROS-Mediated Pyroptosis via Activating ApoE/LDLR Pathway in Influenza A-Induced Acute Lung Injury

“…Melatonin (N-acetyl-5-methoxytryptamine, C 13 H 16 N 2 O 2 ), a kind of neuroendocrine hormone, is mainly synthesized and secreted by the pineal gland of brains and exerts effects via its membrane receptors (MT1 and MT2) [ 20 , 21 ]. Melatonin is also synthesized in respiratory epithelia and bone marrow cells as well as macrophages [ 22 , 23 ].…”

“…Melatonin is also synthesized in respiratory epithelia and bone marrow cells as well as macrophages [ 22 , 23 ]. It is widely recognized that melatonin is in charge of regulating sleep and circadian rhythm and also plays important roles in anti-inflammation and antioxidation [ 20 ]. Recent evidence indicated that melatonin had potential abilities of antivirus infection, including respiratory syncytial virus (RSV), influenza virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [ 24 , 25 ].…”

A Review of the Potential Effects of Melatonin in Compromised Mitochondrial Redox Activities in Elderly Patients With COVID-19

“…Its pro-inflammatory properties have been well-documented in several studies of leukocyte-derived cell lines; therefore, melatonin may be detrimental in autoimmune diseases ( 215 ), rheumatoid arthritis ( 268 ), and multiple sclerosis ( 269 ). The immune effects of melatonin are condition-based, although the conditions are not fully understood ( 270 , 271 ). Melatonin exhibits pro-oxidant, pro-apoptotic, and SIRT1-downregulating properties in cancer cells.…”

Dietary factors and thyroid dysfunction

“…Melatonin (N-acetyl-5-methoxy-tryptamine) is a hormone primarily synthesized by the epiphysis (pineal gland) from L-tryptophan through enzymatic cascade reactions, following a circadian rhythm (59). Apart from epiphysis, melatonin synthesis was reported in other endocrine organs, neural structures, and immunocompetent cells (60). Beyond chronobiology functions, melatonin exerts antioxidant, antiproliferative, antiinflammatory, immunomodulatory, metabolic, and other beneficial effects (61).…”