Melatonin effects on sleep quality and outcomes of COVID-19 patients: An open-label, randomized, controlled trial

Precision nutrition to reset virus-induced human metabolic reprogramming and dysregulation (HMRD) in long-COVID

SARS-CoV-2, the etiological agent of COVID-19, is devoid of any metabolic capacity; therefore, it is critical for the viral pathogen to hijack host cellular metabolic machinery for its replication and propagation. This single-stranded RNA virus with a 29.9 kb genome encodes 14 open reading frames (ORFs) and initiates a plethora of virus-host protein-protein interactions in the human body. These extensive viral protein interactions with host-specific cellular targets could trigger severe human metabolic reprogramming/dysregulation (HMRD), a rewiring of sugar-, amino acid-, lipid-, and nucleotide-metabolism(s), as well as altered or impaired bioenergetics, immune dysfunction, and redox imbalance in the body. In the infectious process, the viral pathogen hijacks two major human receptors, angiotensin-converting enzyme (ACE)-2 and/or neuropilin (NRP)-1, for initial adhesion to cell surface; then utilizes two major host proteases, TMPRSS2 and/or furin, to gain cellular entry; and finally employs an endosomal enzyme, cathepsin L (CTSL) for fusogenic release of its viral genome. The virus-induced HMRD results in 5 possible infectious outcomes: asymptomatic, mild, moderate, severe to fatal episodes; while the symptomatic acute COVID-19 condition could manifest into 3 clinical phases: (i) hypoxia and hypoxemia (Warburg effect), (ii) hyperferritinemia ('cytokine storm'), and (iii) thrombocytosis (coagulopathy). The mean incubation period for COVID-19 onset was estimated to be 5.1 days, and most cases develop symptoms after 14 days. The mean viral clearance times were 24, 30, and 39 days for acute, severe, and ICU-admitted COVID-19 patients, respectively. However, about 25-70% of virus-free COVID-19 survivors continue to sustain virus-induced HMRD and exhibit a wide range of symptoms that are persistent, exacerbated, or new 'onset' clinical incidents, collectively termed as post-acute sequelae of COVID-19 (PASC) or long COVID. PASC patients experience several debilitating clinical condition(s) with >200 different and overlapping symptoms that may last for weeks to months. Chronic PASC is a cumulative outcome of at least 10 different HMRD-related pathophysiological mechanisms involving both virus-derived virulence factors and a multitude of innate host responses. Based on HMRD and virus-free clinical impairments of different human organs/systems, PASC patients can be categorized into 4 different clusters or sub-phenotypes: sub-phenotype-1 (33.8%) with cardiac and renal manifestations; sub-phenotype-2 (32.8%) with respiratory, sleep and anxiety disorders; sub-phenotype-3 (23.4%) with skeleto-muscular and nervous disorders; and sub-phenotype-4 (10.1%) with digestive and pulmonary dysfunctions. This narrative review elucidates the effects of viral hijack on host cellular machinery during SARS-CoV-2 infection, ensuing detrimental effect(s) of virus-induced HMRD on human metabolism, consequential symptomatic clinical implications, and damage to multiple organ systems; as well as chronic pathophysiological sequelae in virus-free PASC patients. We have also provided a few evidence-based, human randomized controlled trial (RCT)-tested, precision nutrients to reset HMRD for health recovery of PASC patients.

A mid‑pandemic night's dream: Melatonin, from harbinger of anti‑inflammation to mitochondrial savior in acute and long COVID‑19 (Review)

Coronavirus disease 2019 (COVID‑19), a systemic illness caused by severe acute respiratory distress syndrome 2 (SARS‑CoV‑2), has triggered a worldwide pandemic with symptoms ranging from asymptomatic to chronic, affecting practically every organ. Melatonin, an ancient antioxidant found in all living organisms, has been suggested as a safe and effective therapeutic option for the treatment of SARS‑CoV‑2 infection due to its good safety characteristics and broad‑spectrum antiviral medication properties. Melatonin is essential in various metabolic pathways and governs physiological processes, such as the sleep‑wake cycle and circadian rhythms. It exhibits oncostatic, anti‑inflammatory, antioxidant and anti‑aging properties, exhibiting promise for use in the treatment of numerous disorders, including COVID‑19. The preventive and therapeutic effects of melatonin have been widely explored in a number of conditions and have been well‑established in experimental ischemia/reperfusion investigations, particularly in coronary heart disease and stroke. Clinical research evaluating the use of melatonin in COVID‑19 has shown various improved outcomes, including reduced hospitalization durations; however, the trials are small. Melatonin can alleviate mitochondrial dysfunction in COVID‑19, improve immune cell function and provide antioxidant properties. However, its therapeutic potential remains underexplored due to funding limitations and thus further investigations are required.

Association of Sleep Quality With Fatigue in Post-COVID-19 Patients in an Indian Population

OBJECTIVE

The aims of the study are to assess the quality of sleep in recently recovered COVID-19 and long-COVID cases and to determine its associations with fatigue and pain.

METHODS

Post-COVID-19 cases ( n = 201) and controls ( n = 206) were assessed using the Pittsburgh Sleep Quality Index questionnaire for sleep quality, Fatigue Severity Scale for fatigue, and Numeric Pain Rating Scale for pain in this observational study.

RESULTS

Global Pittsburgh Sleep Quality Index score was higher ( P ≤ 0.001) among cases (5.7 ± 5.1; 95% confidence interval, 5.0-6.4) than controls (2.1 ± 2.0; 95% confidence interval, 1.8-2.4). Normal sleep latency was observed in 56 (27.9%) patients and 164 (79.6%) controls ( P < 0.001). Fatigue Severity Scale score was higher ( P ≤ 0.001) among cases (16.8 ± 10.2; 95% confidence interval, 15.4, 18.2) against controls (10.9 ± 4.1; 95% confidence interval, 10.3-11.4). The Fatigue Severity Scale scores in mild, moderate, and severe COVID-19 were 14.3 ± 8.1, 22.1 ± 10.8, and 22.8 ± 13, respectively ( P < 0.001) and higher in the older (20.7 ± 12.1) and middle-aged (19.6 ± 10.3) than in younger (13.9 ± 8.3) ( P ≤ 0.001) cases. The global Pittsburgh Sleep Quality Index score was positively correlated with the Fatigue Severity Scale ( r = 0.755, P < 0.001) and Numeric Pain Rating Scale scores ( r = 0.657, P < 0.001). Numeric Pain Rating Scale score correlated with Fatigue Severity Scale score ( r = 0.710, P < 0.001). Fatigue Severity Scale and global Pittsburgh Sleep Quality Index scores were higher in the long-COVID group ( P < 0.001).

CONCLUSIONS

Significantly poor sleep quality was observed in post-COVID-19 individuals including long COVID being positively associated with fatigue and pain.

Signaling pathways in macrophages: molecular mechanisms and therapeutic targets

Macrophages play diverse roles in development, homeostasis, and immunity. Accordingly, the dysfunction of macrophages is involved in the occurrence and progression of various diseases, such as coronavirus disease 2019 and atherosclerosis. The protective or pathogenic effect that macrophages exert in different conditions largely depends on their functional plasticity, which is regulated via signal transduction such as Janus kinase-signal transducer and activator of transcription, Wnt and Notch pathways, stimulated by environmental cues. Over the past few decades, the molecular mechanisms of signaling pathways in macrophages have been gradually elucidated, providing more alternative therapeutic targets for diseases treatment. Here, we provide an overview of the basic physiology of macrophages and expound the regulatory pathways within them. We also address the crucial role macrophages play in the pathogenesis of diseases, including autoimmune, neurodegenerative, metabolic, infectious diseases, and cancer, with a focus on advances in macrophage-targeted strategies exploring modulation of components and regulators of signaling pathways. Last, we discuss the challenges and possible solutions of macrophage-targeted therapy in clinical applications. We hope that this comprehensive review will provide directions for further research on therapeutic strategies targeting macrophage signaling pathways, which are promising to improve the efficacy of disease treatment.

Sleep and critical illness: a review

Critical illness and stays in the Intensive Care Unit (ICU) have significant impact on sleep. Poor sleep is common in this setting, can persist beyond acute critical illness, and is associated with increased morbidity and mortality. In the past 5 years, intensive care clinical practice guidelines have directed more focus on sleep and circadian disruption, spurring new initiatives to study and improve sleep complications in the critically ill. The global SARS-COV-2 (COVID-19) pandemic and dramatic spikes in patients requiring ICU level care also brought augmented levels of sleep disruption, the understanding of which continues to evolve. This review aims to summarize existing literature on sleep and critical illness and briefly discuss future directions in the field.

Safety and efficacy of melatonin as an adjuvant therapy in COVID-19 patients: Systematic review and meta-analysis

BACKGROUND

Melatonin might be beneficial to coronavirus disease 2019 (COVID-19) patients in terms of both prevention and treatment. We investigated how melatonin affected various clinical and laboratory results in COVID-19 patients.

METHODS

PubMed, Scopus, Cochrane Library and Web of Science databases were utilized for searching eligible articles fulfilling our inclusion criteria up to December 2022. We used random effect model in case of significant heterogeneity; in other cases, a fixed model was applied. RevMan was used for meta-analysis.

RESULTS

We included 11 studies in our review. Clinical improvement rate was found to be statistically significantly higher in patients taking melatonin than in the control group (OR: 5.09; 95% CI: 2.60-9.96, p ​< ​0.001). Patients receiving melatonin showed a non-significant difference in mortality rate compared to the control group (OR: 0.37; 95% CI: 0.07-1.81, p ​= ​0.22). However, in the randomized controlled trials subgroup, melatonin-treated patients showed significantly lower mortality than did the controls (OR: 0.17; 95% CI: 0.08-0.38, p ​< ​0.001). CRP level was statistically significantly lower due to melatonin treatment (weighted mean difference [WMD] ​= ​-9.85; 95% CI: -18.54 to -1.16, p ​= ​0.03). Length of hospital stay was statistically significantly shorter in patients taking melatonin compared to controls (WMD ​= ​-4.05; 95% CI: -5.39 to -2.7, p ​< ​0.001).

CONCLUSION

Melatonin was found to have substantial effects on COVID-19 patients when used as adjuvant therapy, enhancing clinical improvement and decreasing time to recovery with a shorter length of hospital stay and a shorter duration of mechanical ventilation.

The influence of COVID-19 on colorectal cancer was investigated using bioinformatics and systems biology techniques

Introduction

Coronavirus disease 2019 (COVID-19) is a global pandemic and highly contagious, posing a serious threat to human health. Colorectal cancer (CRC) is a risk factor for COVID-19 infection. Therefore, it is vital to investigate the intrinsic link between these two diseases.

Methods

In this work, bioinformatics and systems biology techniques were used to detect the mutual pathways, molecular biomarkers, and potential drugs between COVID-19 and CRC.

Results

A total of 161 common differentially expressed genes (DEGs) were identified based on the RNA sequencing datasets of the two diseases. Functional analysis was performed using ontology keywords, and pathway analysis was also performed. The common DEGs were further utilized to create a protein-protein interaction (PPI) network and to identify hub genes and key modules. The datasets revealed transcription factors-gene interactions, co-regulatory networks with DEGs-miRNAs of common DEGs, and predicted possible drugs as well. The ten predicted drugs include troglitazone, estradiol, progesterone, calcitriol, genistein, dexamethasone, lucanthone, resveratrol, retinoic acid, phorbol 12-myristate 13-acetate, some of which have been investigated as potential CRC and COVID-19 therapies.

Discussion

By clarifying the relationship between COVID-19 and CRC, we hope to provide novel clues and promising therapeutic drugs to treat these two illnesses.

Melatonin effects on sleep quality of COVID-19 patients: a protocol for systematic review and meta-analysis of randomised controlled trials with trial sequential analysis

INTRODUCTION

Sleep disturbance is one of the common complaints of patients with COVID-19 infection. Melatonin is a physiological indoleamine involved in circadian rhythm regulation and it is currently used for secondary sleep disorders caused by various diseases. Some clinical randomised controlled trials (RCTs) have obtained a small amount of evidence and controversial results in support of their therapeutic effect on sleep disorders, but no studies have summarised and evaluated RCTs in all current databases to obtain conclusive results. Therefore, the aim of this systematic review and meta-analysis was to determine the efficacy and safety of melatonin in the treatment of sleep disturbances in patients with COVID-19.

METHODS AND ANALYSIS

We will search for RCT-type studies of melatonin in the treatment of sleep disturbances in patients with COVID-19. From inception to October 2022 will be available on PubMed/MEDLINE, Web of Science, Embase, CINAHL, PsycINFO, LILACS, SCOPUS, Cochrane Central Register of Controlled Trials, ICTRP, Wanfang Data, VIP database and CNKI, VIP database, China Biomedical Literature Database to search for eligible studies. There are no language and geographical restrictions. Two authors will independently screen and select eligible studies, assess methodological quality and perform data extraction. Two additional authors will independently extract data from each study. Then, meta-analysis will then be carried out using a fixed-effects or random-effects model, using the mean difference for continuous outcomes and the relative risk for dichotomous outcomes. Risk of bias assessment will be assessed using the Cochrane risk-of-bias tool. Heterogeneity between studies was assessed by Cochrane Q-test and I2. The quality of evidence for each outcome will be assessed using the Grading of Recommendations Assessment, Development and Evaluation methodology. Funnel plots, Begg's test and Egger's test will be used to assess the risk of publication bias. Subgroup analysis, data synthesis, meta-analysis and overall incidence of adverse events will be performed using Review Manager V.5.4 software and Stata software. Trial sequential analysis will be performed if appropriate.

ETHICS AND DISSEMINATION

This study is an extraction review of data from existing studies, and thus it is unnecessary to obtain ethical approval. The results of this systematic review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022359221.

Spiroindole-containing compounds bearing phosphonate group of potential Mpro-SARS-CoV-2 inhibitory properties

Microwave-assisted reaction of 3,5-bis((E)-ylidene)-1-phosphonate-4-piperidones 3a‒g with azomethine ylide (produced through interaction of isatins 4 and sarcosine 5) cycloaddition afforded the corresponding (dispiro[indoline-3,2'-pyrrolidine-3',3″-piperidin]-1″-yl)phosphonates 6a‒l in excellent yields (80-95%). Structure of the synthesized agents was evidenced by single crystal X-ray studies of 6d, 6i and 6l. Some of the synthesized agents revealed promising anti-SARS-CoV-2 properties in the viral infected Vero-E6 cell technique with noticeable selectivity indices. Compounds 6g and 6b are the most promising agents synthesized (R = 4-BrC₆H₄, Ph; R' = H, Cl, respectively) with considerable selectivity index values. M^pro-SARS-CoV-2 inhibitory properties supported the anti-SARS-CoV-2 observations of the potent analogs synthesized. Molecular docking studies (PDB ID: 7C8U) are consistent with the M^pro inhibitory properties. The presumed mode of action was supported by both experimentally investigated M^pro-SARS-CoV-2 inhibitory properties and explained by docking observations.

The clinical efficacy of melatonin in the treatment of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials

Background

The COVID-19 pandemic has resulted in significant morbidity and mortality worldwide, with cytokine storm leading to exaggerating immune response, multi-organ dysfunction and death. Melatonin has been shown to have anti-inflammatory and immunomodulatory effects and its effect on COVID-19 clinical outcomes is controversial. This study aimed to conduct a meta-analysis to evaluate the impact of melatonin on COVID-19 patients.

Methods

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched without any language or publication year limitations from inception to 15 Nov 2022. Randomized controlled trials (RCTs) using melatonin as therapy in COVID-19 patients were included. The primary outcome was mortality, and the secondary outcomes included were the recovery rate of clinical symptoms, changes in the inflammatory markers like C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and neutrophil to lymphocyte ratio (NLR). A random-effects model was applied for meta-analyses, and further subgroup and sensitivity analyses were also conducted.

Results

A total of nine RCTs with 718 subjects were included. Five studies using melatonin with the primary outcome were analyzed, and the pooled results showed no significant difference in mortality between melatonin and control groups with high heterogeneity across studies identified (risk ratio [RR] 0.72, 95% confidence interval [CI] 0.47-1.11, p = 0.14, I2 = 82%). However, subgroup analyses revealed statistically significant effects in patients aged under 55 years (RR 0.71, 95% CI 0.62-0.82, p < 0.01) and in patients treated for more than 10 days (RR 0.07, 95% CI 0.01-0.53, p = 0.01). The recovery rate of clinical symptoms and changes in CRP, ESR, and NLR were not statistically significant. No serious adverse effects were reported from melatonin use.

Conclusion

In conclusion, based on low certainty of evidence, the study concluded that melatonin therapy does not significantly reduce mortality in COVID-19 patients, but there are possible benefits in patients under 55 years or treated for more than 10 days. With a very low certainty of evidence, we found no significant difference in the recovery rate of COVID-19 related symptoms or inflammatory markers in current studies. Further studies with larger sample sizes are warranted to determine the possible efficacy of melatonin on COVID-19 patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022351424.

Melatonin as mitochondria-targeted drug

Oxidative damage is associated to numerous diseases as well as aging development. Mitochondria found in most eukaryotic organisms to create the energy of the cell, generate free radicals during its action and they are chief targets of the oxidants. Mitochondrial activities outspread outside the borders of the cell and effect human physiology by modulating interactions among cells and tissues. Therefore, it has been implicated in several human disorders and conditions. Melatonin (MLT) is an endogenously created indole derivative that modifies several tasks, involving mitochondria-associated activities. These possessions make MLT a powerful defender against a selection of free radical-linked disorders. MLT lessens mitochondrial anomalies causing from extreme oxidative stress and may improve mitochondrial physiology. It is a potent and inducible antioxidant for mitochondria. MLT is produced in mitochondria of conceivably of all cells and it also appears to be a mitochondria directed antioxidant which has related defensive properties as the synthesized antioxidant molecules. This chapter summarizes the suggestion that MLT is produced in mitochondria as well as disorders of mitochondrial MLT production that may associate to a number of mitochondria-linked diseases. MLT as a mitochondria-targeted drug is also discussed.

Melatonin: Both a Messenger of Darkness and a Participant in the Cellular Actions of Non-Visible Solar Radiation of Near Infrared Light

Throughout the history of melatonin research, almost exclusive focus has been on nocturnally-generated pineal melatonin production, which accounts for its circadian rhythm in the blood and cerebrospinal fluid; these light/dark melatonin cycles drive the daily and seasonal photoperiodic alterations in organismal physiology. Because pineal melatonin is produced and secreted primarily at night, it is referred to as the chemical expression of darkness. The importance of the other sources of melatonin has almost been ignored. Based on current evidence, there are at least four sources of melatonin in vertebrates that contribute to the whole-body melatonin pool. These include melatonin produced by (1) the pineal gland; (2) extrapineal cells, tissues, and organs; (3) the microbiota of the skin, mouth, nose, digestive tract, and vagina as well as (4) melatonin present in the diet. These multiple sources of melatonin exhibit differentially regulated mechanisms for its synthesis. Visible light striking the retina or an intense physical stimulus can suppress nocturnal pineal melatonin levels; in contrast, there are examples where extrapineal melatonin levels are increased during heavy exercise in daylight, which contains the whole range of NIR radiation. The cumulative impact of all cells producing augmented extrapineal melatonin is sufficient to elevate sweat concentrations, and potentially, if the exposure is sustained, to also increasing the circulating values. The transient increases in sweat and plasma melatonin support the premise that extrapineal melatonin has a production capacity that exceeds by far what can be produced by the pineal gland, and is used to maintain intercellular homeostasis and responds to rapid changes in ROS density. The potential regulatory mechanisms of near infrared light (NIR) on melatonin synthesis are discussed in detail herein. Combined with the discovery of high levels of melanopsin in most fat cells and their response to light further calls into question pineal centric theories. While the regulatory processes related to microbiota-derived melatonin are currently unknown, there does seem to be crosstalk between melatonin derived from the host and that originating from microbiota.

Endoplasmic Reticulum Stress in Elderly Patients with COVID-19: Potential of Melatonin Treatment

Aging processes, including immunosenescence, inflammation, inflammasome formation, genomic instability, telomeric attrition, and altered autophagy, are involved in viral infections and they may contribute to increased pathophysiological responses to the SARS-CoV-2 infection in the elderly; this poses additional risks of accelerated aging, which could be found even after recovery. Aging is associated with oxidative damage. Moreover, SARS-CoV-2 infections may increase the production of reactive oxygen species and such infections will disturb the Ca++ balance via an endoplasmic reticulum (ER) stress-mediated unfolded protein response. Although vaccine development and anti-inflammation therapy lower the severity of COVID-19, the prevalence and mortality rates are still alarming in some countries worldwide. In this review, we describe the involvement of viral proteins in activating ER stress transducers and their downstream signals and in inducing inflammation and inflammasome formation. Furthermore, we propose the potential of melatonin as an ER stress modulator, owing to its antioxidant, anti-inflammatory, and immunoregulatory effects in viral infections. Considering its strong safety profile, we suggest that additive melatonin supplementation in the elderly could be beneficial in treating COVID-19.

Melatonin Mitigates Cisplatin-Induced Ovarian Dysfunction via Altering Steroidogenesis, Inflammation, Apoptosis, Oxidative Stress, and PTEN/PI3K/Akt/mTOR/AMPK Signaling Pathway in Female Rats

Ovarian damage and fertility impairment are major side effects of chemotherapy in pre-menopausal cancer patients. Cisplatin is a widely used chemotherapeutic drug. The present study was designed to assess the ameliorative effects of melatonin as an adjuvant for fertility preservation. Thirty-two adult female Wistar rats were divided randomly into four equal groups: Control, Melatonin, Cisplatin (CP) treated, and CP + Melatonin treated. The cisplatin-treated group showed decreased body and ovarian weights, decreased serum E2 and AMH, increased serum LH and FSH, reduced ovarian levels of SOD, CAT, GSH, and TAC, and increased ovarian MDA. The histopathological examination of the cisplatin-treated group showed deleterious changes within ovarian tissue in the form of damaged follicles and corpus luteum, hemorrhage, and inflammatory infiltrates with faint PAS reaction in zona pellucida, increased ovarian collagen deposition, and marked expression of caspase-3 immune reaction in granulosa and theca cells, stroma, and oocytes. Alongside, there was a significant downregulation in the mRNA expression of steroidogenic enzymes, IL10, AMPK, PI3K, AKT, mTOR, and PTEN, while TGF-β1, IL1β, IL6, TNF-α, NF-Kβ, P53, p38-MAPK, JNK, and FOXO3 mRNA expressions were upregulated in cisplatin-treated rats' ovarian tissue. Coadministration of cisplatin-treated rats with melatonin reversed these changes significantly. In conclusion, melatonin's antioxidant, anti-inflammatory, and anti-apoptotic activities could modulate ovarian disturbances induced by cisplatin and preserve fertility.

Melatonin-Microbiome Two-Sided Interaction in Dysbiosis-Associated Conditions

Melatonin is a pineal indolamine, allegedly known as a circadian rhythm regulator, and an antioxidative and immunomodulatory molecule. In both experimental and clinical trials, melatonin has been shown to have positive effects in various pathologies, as a modulator of important biochemical pathways including inflammation, oxidative stress, cell injury, apoptosis, and energy metabolism. The gut represents one of melatonin's most abundant extra pineal sources, with a 400-times-higher concentration than the pineal gland. The importance of the gut microbial community-namely, the gut microbiota, in multiple critical functions of the organism- has been extensively studied throughout time, and its imbalance has been associated with a variety of human pathologies. Recent studies highlight a possible gut microbiota-modulating role of melatonin, with possible implications for the treatment of these pathologies. Consequently, melatonin might prove to be a valuable and versatile therapeutic agent, as it is well known to elicit positive functions on the microbiota in many dysbiosis-associated conditions, such as inflammatory bowel disease, chronodisruption-induced dysbiosis, obesity, and neuropsychiatric disorders. This review intends to lay the basis for a deeper comprehension of melatonin, gut microbiota, and host-health subtle interactions.

The role of melatonin as an adjuvant in the treatment of COVID-19: A systematic review

Introduction

Since November 2019, the world has been grappling with the rapid spread of the Coronavirus disease 2019 (COVID-19). In response to this major health crisis, the first vaccination rollout was launched in December 2020. However, even fully vaccinated individuals are not completely immune to infection, albeit with less severe symptoms. Melatonin is known as an anti-oxidant, anti-inflammatory, and immunomodulatory agent whose anti-viral properties, cost-effectiveness, and relatively few side effects make it a potential adjuvant in the treatment of COVID-19. This systematic review aims to summarize the clinical studies on the effects of melatonin on COVID-19 patients.

Methods

The search of articles was carried out in the Web of Science, PubMed/MEDLINE, Cochrane library, and Scopus databases up to January 2022.

Results

Ten articles were included in our study. It seems melatonin can decrease inflammatory markers, inflammatory cytokines, and the expression of some genes, including the signal transducer and activator of transcription (STAT)4, STAT6, T-box expressed in T cell (T-bet), GATA binding protein 3 (GATA3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and caspase-1 (CASP1). In addition, melatonin appears to alleviate some clinical signs and symptoms and accelerate recovery. The use of melatonin in severe cases reduces thrombosis, sepsis, and mortality rate.

Conclusion

This systematic review highlights the probable role of melatonin as a potential adjuvant in the treatment of COVID-19 after about two weeks of consumption. However, further high-quality randomized clinical trials are required.

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Melatonin may be an effective supplemental treatment for COVID-19.

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Melatonin can reduce inflammation, clinical signs and symptoms, and recovery time.

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Melatonin can reduce thrombosis, sepsis, and mortality rate.

The safety and efficacy of melatonin in the treatment of COVID-19: A systematic review and meta-analysis

BACKGROUND

As an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the common signs of coronavirus disease 2019 (COVID-19) are respiratory symptoms, fever, cough, shortness of breath, and dyspnea, with multiple organ injuries in severe cases. Therefore, finding drugs to prevent and treat COVID-19 is urgently needed and expected by the public. Several studies suggested beneficial effects of melatonin for the relevant prevention and treatment. To explore the effect and safety of melatonin in the treatment and provide theoretical support and reference for seeking the most suitable drug for COVID-19, the meta-analysis was carried out accordingly.

METHODS

It included randomized clinical trials of patients with COVID-19 treated with melatonin. Total effective rate was the primary outcome, while C-reactive protein (CRP), arterial oxygen saturation (SaO2), white blood cell count (WBC) were the secondary measures. Random-effect and fixed-effect models were used to evaluate the effect size of some indicators in this meta-analysis.

RESULTS

Six eligible studies with 338 participants were included. One hundred seventy subjects were treated with melatonin adjuvant therapy and 168 subjects were assigned to the control group, with total excellent effective rate in subjects treated with melatonin [odds ratio = 3.05, 95 % confidence interval (CI) = 1.47, 6.31, P = .003]. Homogeneity was analyzed by fixed effect model (I2 = 0%). There was no significant difference in CRP between the melatonin group and the control group (weighted mean difference [WMD] = -0.36, 95% CI = -3.65, 2.92, P = .83). Significant difference was not existed in SaO2 between the melatonin treatment group and the control group (WMD = 1, 95% CI = -1.21, 3.22, P = .37). In terms of WBC, there was no significant difference between the 2 groups (WMD = -1.07, 95% CI = -2.44, 0.30, P = .13).

CONCLUSIONS

The meta-analysis showed that melatonin had the beneficial effects for COVID-19 prevention and treatment as an adjunctive agent in combination with basic treatment for the treatment.

Melatonin drugs inhibit SARS-CoV-2 entry into the brain and virus-induced damage of cerebral small vessels

COVID-19 is a complex disease with short- and long-term respiratory, inflammatory and neurological symptoms that are triggered by the infection with SARS-CoV-2. Invasion of the brain by SARS-CoV-2 has been observed in humans and is postulated to be involved in post-COVID state. Brain infection is particularly pronounced in the K18-hACE2 mouse model of COVID-19. Prevention of brain infection in the acute phase of the disease might thus be of therapeutic relevance to prevent long-lasting symptoms of COVID-19. We previously showed that melatonin or two prescribed structural analogs, agomelatine and ramelteon delay the onset of severe clinical symptoms and improve survival of SARS-CoV-2-infected K18-hACE2 mice. Here, we show that treatment of K18-hACE2 mice with melatonin and two melatonin-derived marketed drugs, agomelatine and ramelteon, prevents SARS-CoV-2 entry in the brain, thereby reducing virus-induced damage of small cerebral vessels, immune cell infiltration and brain inflammation. Molecular modeling analyses complemented by experimental studies in cells showed that SARS-CoV-2 entry in endothelial cells is prevented by melatonin binding to an allosteric-binding site on human angiotensin-converting enzyme 2 (ACE2), thus interfering with ACE2 function as an entry receptor for SARS-CoV-2. Our findings open new perspectives for the repurposing of melatonergic drugs and its clinically used analogs in the prevention of brain infection by SARS-CoV-2 and COVID-19-related long-term neurological symptoms.

The use of melatonin in Danish intensive care departments-A nationwide observational study

BACKGROUND

Melatonin is widely employed as a hypnotic in various patient groups. In intensive care patients, melatonin seems to be increasingly used due to potential clinical effects and a favourable safety profile.

OBJECTIVES

We aimed to investigate the extend of usage and clinical practice of melatonin therapy in intensive care departments in Denmark.

DESIGN

Data from regional hospital pharmacies and the Danish Intensive Care Database were used to estimate defined daily dose and defined daily dose per 1000 ICU admission days. Also, related expenses in the period 2015-2019. Finally, a questionnaire describing the clinical practice of melatonin therapy was provided to all Danish intensive care departments.

PRINCIPAL OBSERVATIONS

The usage of melatonin in intensive care departments in Denmark increased from 21,300 DDD (200.0 DDD per 1000 ICU admission days) in 2015 to 52,170 DDD (560.7 DDD per 1000 ICU admission days) in 2019. A total of 32 ICU departments participated in the study (97% of all Danish ICU departments). All included ICU departments employed melatonin as a hypnotic. Nineteen percent of included departments administered melatonin to all admitted patients, whereas 25% of departments rarely administered melatonin. Magistral melatonin 3-mg tablets was the most employed drug dose/formulation. Increased doses of melatonin were administered in selected patients. Melatonin was considered safe by prescribing clinicians.

CONCLUSIONS

Melatonin is widely and increasingly used in Danish intensive care departments. The more than doubled usage of melatonin in the study period advocates for further studies employing validated outcomes of sleep and other patient-relevant outcomes.

EDITORIAL COMMENT

This study documents that melatonin is frequently used as a hypnotic in Danish intensive care units during recent years despite a shortage of reliable evidence to support a recommendation to treat with melatonin in this context. These results support a need for conducting clinical trials to determine whether or not there is a beneficial effect of melatonin treatment in critically ill patients.

The circadian rhythm of viruses and its implications on susceptibility to infection

INTRODUCTION

Circadian genes have an impact on multiple hormonal, metabolic, and immunological pathways and have recently been implicated in some infectious diseases.

AREAS COVERED

We review aspects related to the current knowledge about circadian rhythm and viral infections, their consequences, and the potential therapeutic options.

EXPERT OPINION

Expert opinion: In order to address a problem, it is necessary to know the topic in depth. Although in recent years there has been a growing interest in the role of circadian rhythms, many relevant questions remain to be resolved. Thus, the mechanisms linking the circadian machinery against viral infections are poorly understood. In a clear approach to personalized precision medicine, in order to treat a disease in the most appropriate phase of the circadian rhythm, and in order to achieve the optimal efficacy, it is highly recommended to carry out studies that improve the knowledge about the circadian rhythm.

Efficacy of melatonin in the treatment of patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials

This study investigated the effect of melatonin on clinical outcomes in patients with coronavirus disease 2019 (COVID-19). We searched PubMed, the Web of Science, the Cochrane Library, Ovid MEDLINE, and Clinicaltrials.gov for randomized controlled trials (RCTs) published before September 11, 2021. Only RCTs that compared the clinical efficacy of melatonin with a placebo in the treatment of patients with COVID-19 were included. The primary outcome measure was the clinical recovery rate. We included three RCTs in this meta-analysis. Melatonin 3 mg three times daily was administered in one RCT, and 3 or 6 mg daily before bedtime in the other two trials. Treatment duration was 14 days in two RCTs and 7 days in one trial. The clinical recovery rates were 94.2% (81/86) and 82.4% (70/85) in the melatonin and control groups, respectively. Overall, patients receiving melatonin had a higher clinical recovery rate than did the controls (odds ratio [OR]: 3.67; 95% CI: 1.21-11.12; I²  = 0%, p = 0.02). The risk of intensive care unit admission was numerically lower in the melatonin group than in the control group (8.3% [6/72] vs. 17.6% [12/68], OR: 0.45; 95% CI: 0.16-1.25; I²  = 0%, p = 0.13), and the risk of mortality was numerically lower in the melatonin group than in the control group (1.4% [1/72] vs. 4.4% [3/68], OR: 0.32; 95% CI: 0.03-3.18; I²  = 0%, p = 0.33). In conclusion, melatonin may help improve the clinical outcomes of patients with COVID-19.

Immune Signature of COVID-19: In-Depth Reasons and Consequences of the Cytokine Storm

In the beginning of the third year of the fight against COVID-19, the virus remains at least still one step ahead in the pandemic "war". The key reasons are evolving lineages and mutations, resulting in an increase of transmissibility and ability to evade immune system. However, from the immunologic point of view, the cytokine storm (CS) remains a poorly understood and difficult to combat culprit of the extended number of in-hospital admissions and deaths. It is not fully clear whether the cytokine release is a harmful result of suppression of the immune system or a positive reaction necessary to clear the virus. To develop methods of appropriate treatment and therefore decrease the mortality of the so-called COVID-19-CS, we need to look deeply inside its pathogenesis, which is the purpose of this review.

Mechanisms and clinical evidence to support melatonin's use in severe COVID-19 patients to lower mortality

The fear of SARS-CoV-2 infection is due to its high mortality related to seasonal flu. To date, few medicines have been developed to significantly reduce the mortality of the severe COVID-19 patients, especially those requiring tracheal intubation. The severity and mortality of SARS-CoV-2 infection not only depend on the viral virulence, but are primarily determined by the cytokine storm and the destructive inflammation driven by the host immune reaction. Thus, to target the host immune response might be a better strategy to combat this pandemic. Melatonin is a molecule with multiple activities on a virus infection. These include that it downregulates the overreaction of innate immune response to suppress inflammation, promotes the adaptive immune reaction to enhance antibody formation, inhibits the entrance of the virus into the cell as well as limits its replication. These render it a potentially excellent candidate for treatment of the severe COVID-19 cases. Several clinical trials have confirmed that melatonin when added to the conventional therapy significantly reduces the mortality of the severe COVID-19 patients. The cost of melatonin is a small fraction of those medications approved by FDA for emergency use to treat COVID-19. Because of its self-administered, low cost and high safety margin, melatonin could be made available to every country in the world at an affordable cost. We recommend melatonin be used to treat severe COVID-19 patients with the intent of reducing mortality. If successful, it would make the SARS-CoV-2 pandemic less fearful and help to return life back to normalcy.

Melatonin Use for SARS-CoV-2 Infection:Time to Diversify the Treatment Portfolio

We were pleased to read the publication by Lan and colleagues [1] which included a meta-analysis of the Randomized Controlled Trials (RTCs) in which melatonin was used as a treatment for COVID-19. This article is protected by copyright. All rights reserved.

Management of Chronic Insomnia Using Cognitive Behavior Therapy for Insomnia (CBT-I) During COVID-19 Pandemic: Does One Shoe Fit All?

PURPOSE

Insomnia is a highly prevalent disorder that is seen across all age groups causing significant morbidity to the patients. Its prevalence has further risen during COVID-19 pandemic. It is widely acknowledged that untreated insomnia can lead to significant health risks and socio-occupational dysfunction.

METHODS

A narrative review was conducted following focused search of databases.

RESULTS

Available guidelines mention two different approaches for the management of insomnia-pharmacological and non-pharmacological. Non-pharmacological therapies like multicomponent cognitive behavior therapy for insomnia (CBT-I) have been advocated for the management of acute as well as chronic insomnia in the literature as it has been found efficacious and useful. Multiple variants of CBT-I, e.g., digitally delivered CBT-I, brief CBT-I have been tested during pandemic owing to closure of clinics. However, there are certain issues to be considered while choosing CBT-I as therapy. For example, like other forms of psychotherapies, is there a need for assessing the candidature of patient before administering CBT-I; is CBT-I free of adverse effects as commonly thought; is CBT-I more efficacious than hypnotics; and at last, how to manage cases that are not candidate for CBT-I.

CONCLUSION

This narrative review addresses the scientific robustness of evidence for issues related to adherence, efficacy and adverse effects of non-pharmacological therapies. Available literature suggests that data related to adherence and efficacy of CBT-I suffer from methodological shortcomings and careful selection of patient is important for the successful therapy. At the same time, attempts have been made to shed light to the areas where CBT-I can be helpful in the management of insomnia.

Melatonin and Related Compounds: Antioxidant and Anti-Inflammatory Actions

Melatonin, an indoleamine derived from tryptophan and produced in the pineal gland and other tissues [...].

Melatonin: highlighting its use as a potential treatment for SARS-CoV-2 infection

Numerous pharmaceutical drugs have been repurposed for use as treatments for COVID-19 disease. These drugs have not consistently demonstrated high efficacy in preventing or treating this serious condition and all have side effects to differing degrees. We encourage the continued consideration of the use of the antioxidant and anti-inflammatory agent, melatonin, as a countermeasure to a SARS-CoV-2 infection. More than 140 scientific publications have identified melatonin as a likely useful agent to treat this disease. Moreover, the publications cited provide the rationale for the use of melatonin as a prophylactic agent against this condition. Melatonin has pan-antiviral effects and it diminishes the severity of viral infections and reduces the death of animals infected with numerous different viruses, including three different coronaviruses. Network analyses, which compared drugs used to treat SARS-CoV-2 in humans, also predicted that melatonin would be the most effective agent for preventing/treating COVID-19. Finally, when seriously infected COVID-19 patients were treated with melatonin, either alone or in combination with other medications, these treatments reduced the severity of infection, lowered the death rate, and shortened the duration of hospitalization. Melatonin’s ability to arrest SARS-CoV-2 infections may reduce health care exhaustion by limiting the need for hospitalization. Importantly, melatonin has a high safety profile over a wide range of doses and lacks significant toxicity. Some molecular processes by which melatonin resists a SARS-CoV-2 infection are summarized. The authors believe that all available, potentially beneficial drugs, including melatonin, that lack toxicity should be used in pandemics such as that caused by SARS-CoV-2.

"MATH+" Multi-Modal Hospital Treatment Protocol for COVID-19 Infection: Clinical and Scientific Rationale

In December 2019, coronavirus disease 2019 (COVID-19), a severe respiratory illness caused by the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China. The greatest impact that COVID-19 had was on intensive care units (ICUs), given that approximately 20% of hospitalized cases developed acute respiratory failure (ARF) requiring ICU admission. Based on the assumption that COVID-19 represented a viral pneumonia and no anti-coronaviral therapy existed, nearly all national and international health care societies recommended "supportive care only" avoiding other therapies outside of randomized controlled trials, with a specific prohibition against the use of corticosteroids in treatment. However, early studies of COVID-19-associated ARF reported inexplicably high mortality rates, with frequent prolonged durations of mechanical ventilation (MV), even from centers expert in such supportive care strategies. These reports led the authors to form a clinical expert panel called the Front-Line COVID-19 Critical Care Alliance (www.flccc.net). The panel collaboratively reviewed the emerging clinical, radiographic, and pathological reports of COVID-19 while initiating multiple discussions among a wide clinical network of front-line clinical ICU experts from initial outbreak areas in China, Italy, and New York. Based on the shared early impressions of "what was working and what wasn't working", the increasing medical journal publications and the rapidly accumulating personal clinical experiences with COVID-19 patients, a treatment protocol was created for the hospitalized patients based on the core therapies of methylprednisolone, ascorbic acid, thiamine, heparin and non-antiviral co-interventions (MATH+). This manuscript reviews the scientific and clinical rationale behind MATH+ based on published in-vitro, pre-clinical, and clinical data in support of each medicine, with a special emphasis of studies supporting their use in the treatment of patients with viral syndromes and COVID-19 specifically.

A Peek into Pandora’s Box: COVID-19 and Neurodegeneration

Ever since it was first reported in Wuhan, China, the coronavirus-induced disease of 2019 (COVID-19) has become an enigma of sorts with ever expanding reports of direct and indirect effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on almost all the vital organ systems. Along with inciting acute pulmonary complications, the virus attacks the cardiac, renal, hepatic, and gastrointestinal systems as well as the central nervous system (CNS). The person-to-person variability in susceptibility of individuals to disease severity still remains a puzzle, although the comorbidities and the age/gender of a person are believed to play a key role. SARS-CoV-2 needs angiotensin-converting enzyme 2 (ACE2) receptor for its infectivity, and the association between SARS-CoV-2 and ACE2 leads to a decline in ACE2 activity and its neuroprotective effects. Acute respiratory distress may also induce hypoxia, leading to increased oxidative stress and neurodegeneration. Infection of the neurons along with peripheral leukocytes’ activation results in proinflammatory cytokine release, rendering the brain more susceptible to neurodegenerative changes. Due to the advancement in molecular biology techniques and vaccine development programs, the world now has hope to relatively quickly study and combat the deadly virus. On the other side, however, the virus seems to be still evolving with new variants being discovered periodically. In keeping up with the pace of this virus, there has been an avalanche of studies. This review provides an update on the recent progress in adjudicating the CNS-related mechanisms of SARS-CoV-2 infection and its potential to incite or accelerate neurodegeneration in surviving patients. Current as well as emerging therapeutic opportunities and biomarker development are highlighted.

Melatonin, Zinc, and Vitamin C: Potential Adjuvant Treatment for COVID-19 Patients

The use of nutraceutical approaches may regulate the immune system, performing a potential strategy to contain the worst outcomes of COVID-19. We reviewed the current evidence surrounding nutritional/nutraceutical approaches for the therapy in patients with COVID-19. We searched the PubMed database to report randomized controlled trials (RCTs) and observational research that used melatonin, zinc, or vitamin C supplementation as an intervention for COVID-19 treatment. To date, we found only three concluded studies that assessed zinc supplementation and melatonin therapy in patients with COVID-19, but with inconclusive data, relatively small sample size, and early termination of the trial. On the other hand, vitamin C therapy appears to reduce hyperinflammation and improve the oxygen support status of patients with COVID-19. However, a large part of this research involves pilot trials, and there are still conflicting data regarding mortality rate, mechanical ventilation, and duration of symptoms of patients with COVID-19. Melatonin, zinc, and vitamin C supplementation should be investigated further on the nutritional status-immune response, and data from ongoing trials are needed to understand these molecules as a therapy strategy in patients COVID-19.

New uses of Melatonin as a Drug, a Review

Melatonin is a simple compound with a proper chemical name N-acetyl-5-methoxy tryptamine and known as a hormone controlling circadian rhythm. Humans produce melatonin at night which is the reason for sleeping in the night and awakening over the day. Melatonin interacts with melatonin receptors MT1 and MT2 but it was also revealed that melatonin is a strong antioxidant and it also has a role in regulation of cell cycle. Currently, melatonin is used as a drug for some types of sleep disorder but the recent research points to the fact that melatonin can also serve for the other purposes including prophylaxis or therapy of lifestyle diseases, cancer, neurodegenerative disorders and exposure to chemicals. This review summarizes basic facts and direction of the current research on melatonin. The actual literature was scrutinized for the purpose of this review.

Melatonin effects on sleep quality and outcomes of COVID-19 patients: An open-label, randomized, controlled trial

This trial aims to evaluate the effectiveness of adding melatonin to the treatment protocol of hospitalized coronavirus disease 2019 (COVID-19) patients. This was an open-label, randomized controlled clinical trial in hospitalized COVID-19 patients. Patients were randomized into a treatment arm receiving melatonin plus standard care or a control arm receiving standard care alone. The trial's primary endpoint was sleep quality examined by the Leeds Sleep Evaluation Questionnaire (LSEQ). The trial's secondary endpoints were symptoms alleviation by Day 7, intensive care unit admission, 10-day mortality, white blood cell count, lymphocyte count, C-reactive protein status, and peripheral capillary oxygen saturation. Ninety-six patients were recruited and allocated to either the melatonin arm (n = 48) or control arm (n = 48). Baseline characteristics were similar across treatment arms. There was no significant difference in symptoms on Day 7. The mean of the LSEQ scores was significantly higher in the melatonin group (p < 0.001). There was no significant difference in laboratory data, except for blood oxygen saturation, which has improved significantly in the melatonin group compared with the control group (95.81% vs. 93.65% respectively, p = 0.003). This clinical trial study showed that the combination of oral melatonin tablets and standard treatment could substantially improve sleep quality and blood oxygen saturation in hospitalized COVID-19 patients.