Parkinson’s and Melatonin

Dr Weeks’ Comment:  Melatonin is not just a sleep aid. It is a powerful anti-inflammatory agent for both fat-soluble and water-soluble vitamins. It also protects brain tissue and nerve function (both fatty tissues) and melatonin is a powerful, life prolonging agent. It is also great support for people with Parkinson’s disease as the research below shows.  But the starting dose is 60mg (not 3 mg) and some people take up to 180mg a day, so my patients get it in a powerful, powder form where 1/16th of a teaspoon is 60 mg and a year’s worth costs about $75.



Cell Mol Neurobiol. 2020 Jan;40(1):15-23.

doi: 10.1007/s10571-019-00720-5. Epub 2019 Aug 6.

Melatonin and Parkinson Disease: Current Status and Future Perspectives for Molecular Mechanisms

Omid Reza Tamtaji 1Russel J Reiter 2Reza Alipoor 3Ehsan Dadgostar 4Ebrahim Kouchaki 1Zatollah Asemi 5


Parkinson disease (PD) is a chronic and neurodegenerative disease with motor and nonmotor symptoms. Multiple pathways are involved in the pathophysiology of PD, including apoptosis, autophagy, oxidative stress, inflammation, α-synuclein aggregation, and changes in the neurotransmitters. Preclinical and clinical studies have shown that melatonin supplementation is an appropriate therapy for PD. Administration of melatonin leads to inhibition of some pathways related to apoptosis, autophagy, oxidative stress, inflammation, α-synuclein aggregation, and dopamine loss in PD. In addition, melatonin improves some nonmotor symptom in patients with PD. Limited studies, however, have evaluated the role of melatonin on molecular mechanisms and clinical symptoms in PD. This review summarizes what is known regarding the impact of melatonin on PD in preclinical and clinical studies.



Biomolecules. 2020 Aug 7;10(8):1158.

doi: 10.3390/biom10081158.

Cellular Mechanisms of Melatonin: Insight from Neurodegenerative Diseases

Dongmei Chen 1Tao Zhang 1Tae Ho Lee 1

Neurodegenerative diseases are the second most common cause of death and characterized by progressive impairments in movement or mental functioning in the central or peripheral nervous system. The prevention of neurodegenerative disorders has become an emerging public health challenge for our society. Melatonin, a pineal hormone, has various physiological functions in the brain, including regulating circadian rhythms, clearing free radicals, inhibiting biomolecular oxidation, and suppressing neuroinflammation. Cumulative evidence indicates that melatonin has a wide range of neuroprotective roles by regulating pathophysiological mechanisms and signaling pathways. Moreover, melatonin levels are decreased in patients with neurodegenerative diseases. In this review, we summarize current knowledge on the regulation, molecular mechanisms and biological functions of melatonin in neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, vascular dementia and multiple sclerosis. We also discuss the clinical application of melatonin in neurodegenerative disorders. This information will lead to a better understanding of the regulation of melatonin in the brain and provide therapeutic options for the treatment of various neurodegenerative diseases.



Int J Mol Sci. 2020 Sep 28;21(19):7174.

doi: 10.3390/ijms21197174.

Melatonin and Autophagy in Aging-Related Neurodegenerative Diseases

Fang Luo 1Aaron F Sandhu 1Wiramon Rungratanawanich 2George E Williams 1Mohammed Akbar 3Shuanhu Zhou 4Byoung-Joon Song 2Xin Wang 1


With aging, the nervous system gradually undergoes degeneration. Increased oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and cell death are considered to be common pathophysiological mechanisms of various neurodegenerative diseases (NDDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), organophosphate-induced delayed neuropathy (OPIDN), and amyotrophic lateral sclerosis (ALS). Autophagy is a cellular basic metabolic process that degrades the aggregated or misfolded proteins and abnormal organelles in cells. The abnormal regulation of neuronal autophagy is accompanied by the accumulation and deposition of irregular proteins, leading to changes in neuron homeostasis and neurodegeneration. Autophagy exhibits both a protective mechanism and a damage pathway related to programmed cell death. Because of its “double-edged sword”, autophagy plays an important role in neurological damage and NDDs including AD, PD, HD, OPIDN, and ALS. Melatonin is a neuroendocrine hormone mainly synthesized in the pineal gland and exhibits a wide range of biological functions, such as sleep control, regulating circadian rhythm, immune enhancement, metabolism regulation, antioxidant, anti-aging, and anti-tumor effects. It can prevent cell death, reduce inflammation, block calcium channels, etc. In this review, we briefly discuss the neuroprotective role of melatoninagainst various NDDs via regulating autophagy, which could be a new field for future translational research and clinical studies to discover preventive or therapeutic agents for many NDDs.


Rev Neurol (Paris). 2020 Mar;176(3):148-165.

doi: 10.1016/j.neurol.2019.07.025. Epub 2019 Nov 11.

Melatonin: A review of its potential functions and effects on neurological diseases

M Gunata 1H Parlakpinar 2H A Acet 1


Background: The aging process is not univocal, both body and brain age. Neurological disorders are a major cause of disability and death worldwide. According to the Global Burden of Disease Study 2015, neurological diseases are the second most common cause of death and 16.8% of total deaths are caused by neurological diseases worldwide. Neurological disease deaths have risen 36% worldwide in 25 years. Melatonin is a neuroregulator hormone that has free radical scavenger, strong antioxidant, anti-inflammatory, and immunosuppressive actions. These major properties of melatonin can play an important role in the pathophysiological mechanisms of neurological diseases. In addition, melatonin is necessary for circadian rhythm. Studies have shown that melatonin levels are low in people with neurological diseases. Both preventive and therapeutic effects of melatonin are known for many diseases, including neurological diseases (e.g., Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis, Huntington’s disease, epilepsy, headache, etc.). Based on all these reasons, clinical trials of melatonin were performed and successful results were declared.

Conclusions: In this review, biological and chemical knowledge of melatonin, its experimental effects, and the clinical impact on patients with neurological disorders were described. According to all of the beneficial results obtained from experimental and clinical trials, melatonin may have a prophylactic and therapeutic effect on neurological diseases. Strong collaboration between neurologists and health service policy makers is needed to encourage use of melatonin in the patients suffering from neurological diseases. Melatonin may be the solution we have been looking for.



J Neurosci Res. 2018 Jul;96(7):1136-1149.

doi: 10.1002/jnr.24220. Epub 2018 Mar 1.

The neuroprotective role of melatonin in neurological disorders

B S Alghamdi 1 2


Melatonin is a neurohormone secreted from the pineal gland and has a wide-ranging regulatory and neuroprotective role. It has been reported that melatonin level is disturbed in some neurological conditions such as stroke, Alzheimer’s disease, and Parkinson’s disease, which indicates its involvement in the pathophysiology of these diseases. Its properties qualify it to be a promising potential therapeutic neuroprotective agent, with no side effects, for some neurological disorders. This review discusses and localizes the effect of melatonin in the pathophysiology of some diseases.



Endocrine. 2005 Jul;27(2):169-78.

doi: 10.1385/ENDO:27:2:169.

Melatonin and Parkinson’s disease

Juan C Mayo 1Rosa M SainzDun-Xian TanIsaac AntolínCarmen RodríguezRussel J Reiter


Parkinson’s disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. It is characterized by a progressive loss of dopamine in the substantia nigra and striatum. However, over 70% of dopaminergic neuronal death occurs before the first symptoms appear, which makes either early diagnosis or effective treatments extremely difficult. Only symptomatic therapies have been used, including levodopa (l-dopa), to restore dopamine content; however, the use of l-dopa leads to some long-term pro-oxidant damage. In addition to a few specific mutations, oxidative stress and generation of free radicals from both mitochondrial impairment and dopamine metabolism are considered to play critical roles in PD etiology. Thus, the use of antioxidants as an important co-treatment with traditional therapies for PD has been suggested. Melatonin, or N-acetyl-5-methoxy-tryptamine, an indole mainly produced in the pineal gland, has been shown to have potent endogenous antioxidant actions. Because neurodegenerative disorders are mainly caused by oxidative damage, melatonin has been tested successfully in both in vivo and in vitro models of PD. The present review provides an up-to-date account of the findings and mechanisms involved in neuroprotection of melatonin in PD.



Curr Pharm Des. 2018;24(14):1563-1588.

doi: 10.2174/1381612824666180426112832.

Role of Melatonin in the Inflammatory Process and its Therapeutic Potential

Livia Carrascal 1Pedro Nunez-Abades 1Antonio Ayala 2Mercedes Cano 1


Melatonin is an indolamine synthesized and secreted by the pineal gland along with other extrapineal sources including immune system cells, the brain, skin and the gastrointestinal tract. Growing interest in this compound as a potential therapeutic agent in several diseases stems from its pleiotropic effects. Thus, melatonin plays a key role in various physiological activities that include regulation of circadian rhythms, immune responses, the oxidative process, apoptosis or mitochondrial homeostasis. Most of these processes are altered during inflammatory pathologies, among which neurodegenerative and bowel diseases stand out. Therapeutic assays with melatonin indicate that it has a beneficial therapeutic value in the treatment of several inflammatory diseases, such as Alzheimer, Amiotrophic Lateral, Multiple Sclerosis and Huntigton´s disease as well as ulcerative colitis. However, contradictory effects have been demonstrated in Parkinson´s and Chron´s diseases, which, in some cases, the reported effects were beneficial while in others the pathology was exacerbated. These various results may be related to several factors. In the first place, it should be taken into account that at the beginning of the inflammation phase there is a production of reactive oxygen species (ROS) that should not be blocked by exclusively antioxidant molecules, since, on the one hand, it would be interfering with the action of neutrophils and macrophages and, on the other, with the apoptotic signals activated by ROS. It is also important to keep in mind that the end result of an anti-inflammatory molecule will depend on the degree of inflammation or whether or not it has been resolved and has therefore become chronic. In this review we present the use of melatonin in the control of inflammation underlying the above mentioned diseases. These actions are mediated through their receptors but also with their direct antioxidant action and melatonin’s ability to break the vicious cycle of ROS inflammation. This review is aimed at evaluating the effect of melatonin on activity of the inflammatory process and at its immunomodulator effects.


Front Pharmacol. 2021 Apr 15;12:650597.

doi: 10.3389/fphar.2021.650597. eCollection 2021.

Melatonin as a Chronobiotic and Cytoprotective Agent in Parkinson’s Disease

Santiago Pérez-Lloret 1 2Daniel P Cardinali 2


This article discusses the role that melatonin may have in the prevention and treatment of Parkinson’s disease (PD).In Parkinsonian patients circulating melatonin levels are consistently disrupted and the potential therapeutic value of melatonin on sleep disorders in PD was examined in a limited number of clinical studies using 2-5 mg/day melatonin at bedtime. The low levels of melatonin MT1 and MT2 receptor density in substantia nigra and amygdala found in PD patients supported the hypothesis that the altered sleep/wake cycle seen in PD could be due to a disrupted melatonergic system. Motor symptomatology is seen in PD patients when about 75% of the dopaminergic cells in the substantia nigra pars compacta region degenerate. Nevertheless, symptoms like rapid eye movement (REM) sleep behavior disorder (RBD), hyposmia or depression may precede the onset of motor symptoms in PD for years and are index of worse prognosis. Indeed, RBD patients may evolve to an α-synucleinopathy within 10 years of RBD onset. Daily bedtime administration of 3-12 mg of melatonin has been demonstrated effective in RDB treatment and may halt neurodegeneration to PD. In studies on animal models of PD melatonin was effective to curtail symptomatology in doses that allometrically projected to humans were in the 40-100 mg/day range, rarely employed clinically. Therefore, double-blind, placebo-controlled clinical studies are urgently needed in this respect.



Drug News Perspect. 2005 Sep;18(7):437-44.

doi: 10.1358/dnp.2005.18.7.939349.

The role of ML-23 and other melatonin analogues in the treatment and management of Parkinson’s disease

Gregory L Willis 1


Contemporary theory regarding the cause and treatment of neuropsychiatric disease strongly suggests that as the human body ages it gradually loses the intrinsic safeguards that protect it from oxidative damage.Melatonin is one hormone that serves this function in that it possesses antioxidative properties in the mammalian body and brain. Melatonin has been shown to prevent the progressive degeneration produced by neurotoxins employed in experimental models to mimic the degenerative events in various neuropsychiatric disease states. There are an abundance of models for numerous disease states demonstrating that melatonin can inhibit oxidative stress and by such a mechanism it is presumed to exert a therapeutic effect. While a similar scenario has been revealed with in vitro work relating specifically to Parkinson’s disease, clinical work with melatonin in this disorder demonstrates that it is devoid of any remarkable therapeutic effects. More recent preclinical and clinical work has reliably demonstrated that melatonin in fact may be without therapeutic efficacy and may even worsen the condition. On this pretense, attempts to reduce the bioavailability of melatonin using a melatonin receptor antagonist have been found to completely restore behavioral and regulatory function in the presence of chronically reduced levels of dopamine, without producing side effects commonly seen with traditional dopamine replacement therapy. The unavoidable conclusion from this work suggests that within the dynamic framework of the mammalian brain, hormones may play a duel, and possibly ambivalent, role in homeostasis and in the etiology of disease. Such a position requires a reevaluation of the etiology, the role of dopamine, the neurochemical characteristics of Parkinson’s disease and the validity of the models employed to study this and other neuropsychiatric disorders.


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