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

Significance of Melatonin in the Regulation of Circadian Rhythms and Disease Management

Melatonin, the 'hormone of darkness' is a neuronal hormone secreted by the pineal gland and other extra pineal sites. Responsible for the circadian rhythm and seasonal behaviour of vertebrates and mammals, melatonin is responsible for regulating various physiological conditions and the maintenance of sleep, body weight and the neuronal activities of the ocular sites. With its unique amphiphilic structure, melatonin can cross the cellular barriers and elucidate its activities in the subcellular components, including mitochondria. Melatonin is a potential scavenger of oxygen and nitrogen-reactive species and can directly obliterate the ROS and RNS by a receptor-independent mechanism. It can also regulate the pro- and anti-inflammatory cytokines in various pathological conditions and exhibit therapeutic activities against neurodegenerative, psychiatric disorders and cancer. Melatonin is also found to show its effects on major organs, particularly the brain, liver and heart, and also imparts a role in the modulation of the immune system. Thus, melatonin is a multifaceted candidate with immense therapeutic potential and is still considered an effective supplement on various therapies. This is primarily due to rectification of aberrant circadian rhythm by improvement of sleep quality associated with risk development of neurodegenerative, cognitive, cardiovascular and other metabolic disorders, thereby enhancing the quality of life.

Protective efficacy of ramelteon on methotrexate-induced DNA damage

Ramelteon (RMLT) is a melatonin receptor agonist that it has antioxidative and anti-inflammatory effects associated with DNA damage through different mechanisms of action. In this regard, we investigated the potential usefulness of RMLT as a protective agent against methotrexate (MTX)-induced DNA damage. Four groups were constituted from 32 Wistar albino rats: Negative control, RMLT, MTX, and MTX + RMLT. Twenty mg/kg MTX (i.p., single dose) and RMLT 10 mg/kg (oral, 7 days) was administered. Comet assay was used and the parameter %TailDNA was used to detect DNA damage. %TailDNA was 4.90 ± 0.19 in the control group, 7.85 ± 0.33 in the MTX group, 5.49 ± 0.24 in the RMLT group, and 5.86 ± 0.23 in the MTX + RMLT group. While there was a significant increase in DNA damage in the MTX-treated group compared to the control group, there was a significant reduction in DNA damage in the MTX + RMLT group, compared to the MTX group (p < 0.001). In conclusion, it was observed that combined treatment with RMLT significantly reduced MTX-induced DNA damage.

Insufficient Plasma Melatonin and Its Association With Neuropsychiatric Impairments in Patients With T2DM

Purpose: Type 2 diabetes mellitus (T2DM) is associated with multiple neuropsychiatric impairments, including cognitive dysfunction, and melatonin (MLT) plays a crucial role in maintaining normal neuropsychiatric functions. This study is aimed at investigating the change in plasma MLT levels and its association with neuropsychiatric impairments in T2DM patients. Methods: One hundred twenty-six T2DM patients were recruited, and their demographics and clinical data were collected. Apart from the plasma glycated hemoglobin (HbA1c) levels and other routine metabolic indicators, the plasma concentrations of MLT, C-reactive protein (CRP), Interleukin 6 (IL-6), soluble myeloid triggered receptor 1 (sTREM 1), and receptor 2 (sTREM 2) were measured. Moreover, the executive function and depressive tendency were evaluated via the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) and the Epidemiological Research Center Depression Scale (CES-D), respectively. Result: Compared with the low HbA1c group, the T2DM patients in the high HbA1c group presented lower plasma MLT levels but higher plasma concentrations of inflammatory biomarker levels, together with higher scores in the BRIEF-A and CES-D scales. Moreover, results of the Pearson correlation test showed that the plasma MLT levels were negatively correlated with the BRIEF-A and CES-D scores, as well as plasma concentrations of HbA1c and inflammatory indications, indicating that MLT may mediate their neuroinflammation and neuropsychiatric impairments. Furthermore, the ROC curve results indicated that plasma MLT levels have a predictive effect on executive impairment and depressive status in T2DM patients. Conclusion: MLT levels decreased in patients with T2DM and were associated with neuropsychiatric impairments and inflammatory status, and MLT might be developed as a therapeutic agent and predictive indicator for T2DM-associated executive impairment and depression status.

Mitochondrial dynamics dysfunction: Unraveling the hidden link to depression

Depression is a common mental disorder and its pathogenesis is not fully understood. However, more and more evidence shows that mitochondrial dynamics dysfunction may play an important role in the occurrence and development of depression. Mitochondria are the centre of energy production in cells, and are also involved in important processes such as apoptosis and oxidative stress. Studies have found that there are abnormalities in mitochondrial function in patients with depression, including mitochondrial morphological changes, mitochondrial dynamics disorders, mitochondrial DNA damage, and impaired mitochondrial respiratory chain function. These abnormalities may cause excessive free radicals and oxidative stress in mitochondria, which further damage cells and affect the balance of neurotransmitters, causing or aggravating depressive symptoms. Studies have shown that mitochondrial dynamics dysfunction may participate in the occurrence and development of depression by affecting neuroplasticity, inflammation and neurotransmitters. This article reviews the effects of mitochondrial dynamics dysfunction on the pathogenesis of depression and its potential molecular pathway. The restorers for the treatment of depression by regulating the function of mitochondrial dynamics were summarized and the possibility of using mitochondrial dynamics as a biomarker of depression was discussed.

Modulation of neural circuits by melatonin in neurodegenerative and neuropsychiatric disorders

Neurodegenerative and neuropsychiatric disorders are two broad categories of neurological disorders characterized by progressive impairments in movement and cognitive functions within the central and peripheral nervous systems, and have emerged as a significant cause of mortality. Oxidative stress, neuroinflammation, and neurotransmitter imbalances are recognized as prominent pathogenic factors contributing to cognitive deficits and neurobehavioral anomalies. Consequently, preventing neurodegenerative and neuropsychiatric diseases has surfaced as a pivotal challenge in contemporary public health. This review explores the investigation of neurodegenerative and neuropsychiatric disorders using both synthetic and natural bioactive compounds. A central focus lies on melatonin, a neuroregulatory hormone secreted by the pineal gland in response to light-dark cycles. Melatonin, an amphiphilic molecule, assumes multifaceted roles, including scavenging free radicals, modulating energy metabolism, and synchronizing circadian rhythms. Noteworthy for its robust antioxidant and antiapoptotic properties, melatonin exhibits diverse neuroprotective effects. The inherent attributes of melatonin position it as a potential key player in the pathophysiology of neurological disorders. Preclinical and clinical studies have demonstrated melatonin's efficacy in alleviating neuropathological symptoms across neurodegenerative and neuropsychiatric conditions (depression, schizophrenia, bipolar disorder, and autism spectrum disorder). The documented neuroprotective prowess of melatonin introduces novel therapeutic avenues for addressing neurodegenerative and psychiatric disorders. This comprehensive review encompasses many of melatonin's applications in treating diverse brain disorders. Despite the strides made, realizing melatonin's full neuroprotective potential necessitates further rigorous clinical investigations. By unravelling the extended neuroprotective benefits of melatonin, future studies promise to deepen our understanding and augment the therapeutic implications against neurological deficits.

A Decade of Dedication: Pioneering Perspectives on Neurological Diseases and Mental Illnesses

Welcome to Biomedicines' 10th Anniversary Special Issue, a journey through the human mind's labyrinth and complex neurological pathways [...].

Animal model of multiple sclerosis: Experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a very complex and heterogeneous disease, with an unknown etiology and which, currently, remains incurable. For this reason, animal models are crucial to investigate this disease, which has increased in prevalence in recent years, affecting 2.8 million people worldwide, and is the leading cause of non-traumatic disability in young adults between the ages of 20-30years. Of all the models developed to replicate MS, experimental autoimmune encephalomyelitis (EAE) best reflects the autoimmune pathogenesis of MS. There are different methods to induce it, which will give rise to different types of EAE, which will vary in clinical presentation and severity. Of the EAE models, the most widespread and used is the one induced in rodents due to its advantages over other species. Likewise, EAE has become a widely used model in the development of therapies for the treatment of MS. Likewise, it is very useful to define the cellular and molecular mechanisms involved in the pathogenesis of MS and to establish therapeutic targets for this disease. For all these reasons, the EAE model plays a key role in improving the understanding of MS.

Melatonin as an add-on treatment for epilepsy: A systematic review and meta-analysis

PURPOSE

Epilepsy, one severe prevalent brain disorder, primarily relies on drug treatment. However, approximately one-third of patients with epilepsy do not achieve effective control with current medications, underscoring the need for more innovative treatment approaches. Notably, melatonin has gained attention for its anti-seizure properties and favourable safety profile. This systematic review aimed to evaluate the efficacy and safety of melatonin as an add-on treatment for epilepsy.

METHODS

We searched for articles published before June 2023 in Web of Science, Cochrane Library, and PubMed. We used RevMan 5.4 software to compute relative risks (RRs) and 95 % confidence intervals (CIs). Key outcomes included total sleep time, wakefulness after sleep onset, sleep latency, seizure frequency, seizure severity, and safety. The quality of randomised controlled studies (RCTs) was assessed using the Cochrane Risk of Bias tool.

RESULTS

Of the 264 publications retrieved, 10 RCTs were included in the meta-analysis. Add-on melatonin treatment improved sleep latency (RR: 0.56; 95 %CI: 0.10-1.02; P = 0.02) and seizure severity (RR: 0.33; 95 %CI: 0.04-0.62; P = 0.03) compared with placebo treatment. Adverse events (increased headache severity in children with a history of migraines, bronchitis, ear infections, agitation, and urinary frequency) were reported in only one trial.

CONCLUSION

This systematic review found that add-on melatonin therapy improved sleep latency and seizure severity in patients with epilepsy. However, several of the included studies did not systematically assess sleep quality, seizures, and safety and lacked long-term follow-up data. Further RCTs with extended follow-up periods are required to definitively determine the efficacy and safety of melatonin.

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.

Strategy for the Optimization of Read-Through Therapy for Junctional Epidermolysis Bullosa with COL17A1 Nonsense Mutation

Read-through therapy suppresses premature termination codons and induces read-through activity, consequently restoring missing proteins. Aminoglycosides are widely studied as read-through drugs in different human genetic disorders, including hereditary skin diseases. Our previous work revealed that aminoglycosides affect COL17A1 nonsense mutations and represent a therapeutic option to alleviate disease severity. However, the amount of restored type XVII collagen (C17) in C17-deficient junctional epidermolysis bullosa keratinocytes was <1% relative to that in normal keratinocytes and was achieved only after high-dose gentamicin treatment, which induced deep transcriptional changes. Therefore, in this study, we designed a strategy combining aminoglycosides with compounds known to reduce their side effects. We developed translational read-through-inducing drug cocktail, version 5 containing low dosage of aminoglycosides, CC-90009, NMDI-14, melatonin, and apocynin that was able to induce about 20% of missing C17 without cell toxicity or an effect on in vitro wound closure. Translational read-through-inducing drugs cocktail, version 5 significantly induced COL17A1 expression and reverted the proinflammatory phenotype of C17-deficient junctional epidermolysis bullosa keratinocytes. Evaluation of this drug cocktail regarding its stability, penetration, and efficacy as a topical treatment remains to be determined. Translational read-through-inducing drug cocktail, version 5 might represent an improved therapeutic strategy for junctional epidermolysis bullosa and for other genetic skin disorders.

Effects of a nighttime melatonin ingestion on dynamic postural balance and muscle strength the following morning in people living with multiple sclerosis: A preliminary study

BACKGROUND

Decreased endogenous melatonin concentrations in people with multiple sclerosis (PwMS) are associated with fatigue and pain that impair postural balance and muscle strength. Melatonin ingestion had analgesic and anti-fatigue effects. However, the acute effect of exogenous melatonin on dynamic postural stability and muscle strength has not been studied yet in PwMS. This study aimed to investigate the safety and the efficacy of a nighttime melatonin intake on dynamic postural balance and lower-extremity muscle strength the following morning in PwMS.

METHODS

Fourteen PwMS (28.36 ± 6.81 years) were assessed (8 a.m.) pre- and post-acute intake of melatonin or placebo (6mg, 30 minutes before nocturnal bedtime). Evaluated parameters included dynamic postural balance (force platform), lower-extremity muscle strength [Five-Repetition Sit-To-Stand Test (5-STST)], hand dexterity (Nine-Hole Peg Test), nociceptive pain [Visual Analogue Scale (VAS)], neuropathic pain [Neuropathic Pain 4 Questions (DN4)], sleep quality and fatigue perception [Hooper Index (HI)].

RESULTS

In the frontal plane, melatonin reduced the center of pressure (CoP) path length (CoPL), CoPL in the anteroposterior axis (CoPLY) and CoP sway area (CoPAr) compared with placebo by 7.56% (p=0.02, Cohens'd (d)=1.24), 19.27% (p<0.001, d=2.60) and 13.82% (p<0.001, d=2.02), respectively. Melatonin induced a higher decrease in these posturographic parameters compared with placebo in the sagittal plane [CoPL: 9.10% (p=0.005, d=1.02), CoPLY: 4.29% (p=0.025, d=1.07) and CoPAr: 7.45% (p=0.038, d=0.74)]. Melatonin decreased 5-STST duration as well as VAS, DN4, HI-fatigue and HI-sleep scores compared with placebo by 8.19% (p=0.008, d=1.19), 5.74% (p=0.04, d=0.82), 27.30% (p=0.023, d=0.98), 40.15% (p=0.044, d=0.85) and 30.16% (p=0.012, d=1.10), respectively.

CONCLUSION

This preliminary study, among PwMS, showed that acute melatonin ingestion was safe and efficient for improving dynamic postural stability and lower-extremity muscle strength probably through its analgesic and anti-fatigue effects.

Melatonin affects the expression of microRNA-21: A mini-review of current evidence

Melatonin (MLT) is an endogenous hormone produced by pineal gland which possess promising anti-tumor effects. Anti-inflammatory and anti-oxidant properties of MLT, along with its immunomodulatory, proapoptotic, and anti-angiogenic properties, are often referred to the main mechanisms of its anti-tumor effects. Recent evidence has suggested that epigenetic alterations are also involved in the anti-tumor properties of MLT. Among these MLT-induced epigenetic alterations is modulation of the expression of several oncogenic and tumor suppressor microRNAs(miRNAs). MiRNAs are among the most promising and potential therapeutic and diagnostic tools in different diseases and enhanced the development of better therapeutic drugs. Suppression of oncomicroRNAs such as microRNA-21, - 20a, and - 27a as well as, up-regulation of microRNA-34 a/c are among the most important effects of MLT on microRNAs homeostasis. Recently, miR-21 has attracted the attention of scientists due to the its wide range of effects on different cancers and diseases. Regulation of this RNA may be a key to the development of better therapeutic targets. The present review will summarize the findings of in vitro and experimental studies of MLT-induced impacts on the expression of microRNAs which are involved in different models and numerous stages of tumor initiation, growth, metastasis, and chemo-resistance.

Melatonin as a master regulatory hormone for genetic responses to biotic and abiotic stresses in model plant Arabidopsis thaliana: a comprehensive review

Melatonin is a naturally occurring biologically active amine produced by plants, animals and microbes. This review explores the biosynthesis of melatonin in plants, with a particular focus on its diverse roles in Arabidopsis thaliana , a model species. Melatonin affects abiotic and biotic stress resistance in A. thaliana . Exogenous and endogenous melatonin is addressed in association with various conditions, including cold stress, high light stress, intense heat and infection with Botrytis cinerea or Pseudomonas , as well as in seed germination and lateral root formation. Furthermore, melatonin confers stress resistance in Arabidopsis by initiating the antioxidant system, remedying photosynthesis suppression, regulating transcription factors involved with stress resistance (CBF, DREB, ZAT, CAMTA, WRKY33, MYC2, TGA) and other stress-related hormones (abscisic acid, auxin, ethylene, jasmonic acid and salicylic acid). This article additionally addresses other precursors, metabolic components, expression of genes (COR , CBF , SNAT , ASMT , PIN , PR1 , PDF1.2 and HSFA ) and proteins (JAZ, NPR1) associated with melatonin and reducing both biological and environmental stressors. Furthermore, the future perspective of melatonin rich agri-crops is explored to enhance plant tolerance to abiotic and biotic stresses, maximise crop productivity and enhance nutritional worth, which may help improve food security.

Neuroprotective and antioxidant effects of docosahexaenoic acid (DHA) in an experimental model of multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease, whose etiology is not yet fully understood, although there are several factors that can increase the chances of suffering from it. These factors include nutrition, which may be involved in the pathogenesis of the disease. In relation to nutrition, docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (n-3 PUFA), has emerged as an important player in the regulation of neuroinflammation, being considered a pleiotropic molecule. This study aimed to evaluate the effect of DHA supplementation on clinical state and oxidative stress produced by experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Twenty-five Dark Agouti rats which were used divided into Control Group, Control+Vehicle Group, Control+DHA Group, EAE Group, and EAE+DHA Group. DHA was administered for 51 days by intraperitoneal (i.p.) injection at a dose of 40 mg/kg, once a day, 5 days a week. DHA supplementation produced a decrease in oxidative stress, as well as an improvement in the clinical score of the disease. DHA could exert a beneficial effect on the clinic of MS, through the activation of the antioxidant factor Nrf2.

LPS-induced inflammation in rats during pregnancy reduces maternal melatonin and impairs neurochemistry and behavior of adult male offspring

Inflammation during pregnancy can induce neurodevelopmental changes that affect the neurological health of offspring. Elevated levels of circulating inflammatory cytokines have been shown to decrease nocturnal melatonin synthesis by the pineal gland, potentially impacting fetal development. This study aimed to assess the effects of LPS-induced inflammation on melatonin concentrations in the plasma of pregnant female rats and explore resulting neurochemical and behavioral changes in their offspring. Our findings revealed that pregnant rats injected with LPS experienced decreased nocturnal melatonin levels in their plasma, with an increase in diurnal melatonin content. The offspring exhibited reduced performance in tests evaluating motor coordination and spatial memory compared to control subjects. Immunohistochemical analysis indicated a decline in calbindin immunoreactivity in Purkinje cells in the cerebellum. Additionally, the hippocampus displayed an increase in IBA-1 and calretinin expression, coupled with a reduction in parvalbumin expression in the offspring of the LPS group. Collectively, this study provides compelling evidence that an inflammatory state can lead to a reduction in melatonin synthesis in pregnant females, potentially impacting the neurodevelopment of offspring, including neuronal, glial, motor, and cognitive aspects. Subsequent studies will further elucidate the mechanisms underlying inflammation-induced maternal melatonin reduction and its impact on offspring neurodevelopment.

The Role of Circadian Rhythms in Stroke: A Narrative Review

Stroke, a debilitating condition often leading to long-term disability, poses a substantial global concern and formidable challenge. The increasing incidence of stroke has drawn the attention of medical researchers and neurologists worldwide. Circadian rhythms have emerged as pivotal factors influencing stroke's onset, pathogenesis, treatment, and outcomes. To gain deeper insights into stroke, it is imperative to explore the intricate connection between circadian rhythms and stroke, spanning from molecular mechanisms to pathophysiological processes. Despite existing studies linking circadian rhythm to stroke onset, there remains a paucity of comprehensive reviews exploring its role in pathogenesis, treatment, and prognosis. This review undertakes a narrative analysis of studies investigating the relationship between circadian variation and stroke onset. It delves into the roles of various physiological factors, including blood pressure, coagulation profiles, blood cells, catecholamines, cortisol, and the timing of antihypertensive medication, which contribute to variations in circadian-related stroke risk. At a molecular level, the review elucidates the involvement of melatonin, circadian genes, and glial cells in the pathophysiology. Furthermore, it provides insights into the diverse factors influencing stroke treatment and outcomes within the context of circadian variation. The review underscores the importance of considering circadian rhythms when determining the timing of stroke interventions, emphasizing the necessity for personalized stroke management strategies that incorporate circadian rhythms. It offers valuable insights into potential molecular targets and highlights areas that require further exploration to enhance our understanding of the underlying pathophysiology. In comparison to the published literature, this manuscript distinguishes itself through its coverage of circadian rhythms' impact on stroke across the entire clinical spectrum. It presents a unique synthesis of epidemiological, clinical, molecular, and cellular evidence, underscoring their collective significance.

Sodium chloride-induced changes in oxidative stress, inflammation, and dysbiosis in experimental multiple sclerosis

Objectives: The high-salt diet (HSD) has been associated with cognitive dysfunction by attacking the cerebral microvasculature, through an adaptive response, initiated in the intestine and mediated by Th17 cells. In the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE), it has been described that NaCl causes an increase in T cell infiltration in the central nervous system. NaCl also promotes macrophage response and Th17 cell differentiation, worsening the course of the disease. HSD may trigger an activation of the immune system and enhance inflammation. However, certain studies not only do not support this possibility, but support the opposite, as the effect of salt on immune cells may not necessarily be pathogenic. Therefore, this study aimed to evaluate the effect of an over intake of salt in rats with EAE, based on the clinical course, oxidative stress, markers of inflammation and the gut dysbiosis.Methods: 15 Dark Agouti rats were used, which were divided into control group, EAE group and EAE + NaCl group. Daily 0.027 g of NaCl dissolved in 300 μl of H2O was administered through a nasogastric tube for 51 days.Results: NaCl administration produced an improvement in clinical status and a decrease in biomarkers of oxidative stress, inflammation, and dysbiosis.Conclusion: The underlying mechanism by which NaCl causes these effects could involve the renin-angiotensin-aldosterone system (RAAS), which is blocked by high doses of salt.

Safety and efficacy of melatonin supplementation as an add-on treatment for infantile epileptic spasms syndrome: A randomized, placebo-controlled, double-blind trial

This was a prospective, randomized, double-blind, single-center placebo-controlled trial to assess the efficacy and safety of melatonin as an add-on treatment for infantile epileptic spasms syndrome (IESS). Participants aged 3 months to 2 years with a primary diagnosis of IESS were recruited and assigned to two groups in a 1:1 ratio. Both treatment groups received a combination of adrenocorticotrophic hormone (ACTH) and magnesium sulfate (MgSO4 ) for 2 weeks, and the treatment group also received melatonin (3 mg) between 20:00 and 21:00 daily, 0.5-1 h before bedtime. The study's primary endpoint was the average reduction rate in spasm frequency assessed by seizure diaries. Secondary endpoints included assessment of the response rate, EEG hypsarrhythmia (Kramer score), and psychomotor development (Denver Developmental Screening Test, DDST). Sleep quality was assessed by using the Brief Infant Sleep Questionnaire (BISQ), the Infant Sleep Assessment Scale (ISAS), and actigraphy. Safety parameters were also evaluated. Statistical analyses were conducted on intention-to-treat and per-protocol populations. The trial is registered at Clinicaltrials.gov (ChiCTR2000036208). Out of 119 screened patients, 70 were randomized and 66 completed treatments. In the intention-to-treat population, there were no significant differences in the average percentage reduction of spasm frequency (median [interquartile range, IQR: Q3-Q1], 100% [46.7%] vs. 66.7% [55.3%], p = .288), the 3-day response rate (51.4% vs. 37.1%, p = .229), the 28-day response rate (42.9% vs. 28.6%, p = .212), EEG Kramer scores (2 [3.5] vs. 2 [3], p = .853), or DDST comprehensive months (5 [2.5] vs. 6 [6], p = .239) between the melatonin (n = 35) and placebo (n = 35) groups. However, caregivers reported improved sleep quality after melatonin treatment, with 85.7% reporting regular sleep compared to 42.9% with placebo (42.9%, p < .001). The melatonin group had lower ISAS scores in 4-11-month-old patients compared to the placebo (mean ± SD, 29.3 ± 4.4 vs. 35.2 ± 5.9, p < .001). Moreover, the median (IQR) value of sleep-onset latency was shortened by 6.0 (24.5) min after melatonin treatment, while that in the placebo group was extended by 3.0 (22.0) min (p = .030). The serum melatonin (6:00 h) level (pg/mL) of the children in the melatonin group after treatment was significantly higher than in the placebo group (median [IQR], 84.8 [142] vs. 17.5 [37.6], p < .001). No adverse effects related to melatonin were observed in the study, and there were no significant differences in adverse effects between the melatonin and placebo groups. Although not statistically significant, the results of this randomized clinical trial proved that melatonin supplementation, as an add-on treatment, can improve spasm control rate in the treatment of IESS. For IESS children treated with ACTH, the addition of melatonin was found to improve sleep quality, shorten sleep onset latency, and increase blood melatonin levels. Moreover, it was observed to be a safe treatment option.

Increasing minor ginsenosides contents and enhancing neuroprotective effects of total ginsenosides fermented by Lactiplantibacillus plantarum

Minor ginsenosides have been proven to have higher pharmacological activity than the major ginsenosides. The transformation of major ginsenosides to minor ginsenosides by lactic acid bacteria was considered to be a promising method. Therefore, this study focuses on utilizing glycosidase-producing Lactiplantibacillus plantarum GLP40 to transform total ginsenosides (TG) and increase the content of minor ginsenosides, as well as investigate the neuroprotective effects of fermented total ginsenosides (FTG). After 21d fermentation, the transformation products were purified using D101 macroporous resin column chromatography, and identified by HPLC and LC-MS analyses. The neuroprotective effect of FTG was evaluated using MPTP-induced neural injury mice model. Lact. plantarum GLP40 fermentation increased the contents of minor ginsenosides in TG, such as Rg3, Rh2, CK, and Rk3. FTG showed stronger alleviation of 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Hydrochloride (MPTP) induced memory loss and dyskinesia in mice, and inhibited tyrosine hydroxylase (TH) depletion and ionized calcium binding adapter molecule 1 (Iba-1) production than TG. Further, FTG significantly increased serum IL-10 levels and inhibited the expression of pro-inflammatory cytokines compared to TG. Moreover, FTG treatment activated the anti-apoptotic PI3K/AKT/mTOR signaling pathway and inhibited the expression of the inflammatory NF-κB/COX-2/iNOS pathway. In conclusion, Lact. plantarum GLP40 fermentation enhances the neuroprotective effects of total ginsenosides by increasing minor ginsenosides. FTG protected MPTP induced neural injury in mice by regulating inflammation and cell apoptosis signaling pathways.

Neuroprotective Potential of Melatonin: Evaluating Therapeutic Efficacy in Alzheimer's and Parkinson's Diseases

Decreased melatonin levels have been linked to both Alzheimer's disease (AD) and Parkinson's disease (PD), which are the two most prevalent neurodegenerative disorders. The development of sleep disorders is widespread in patients diagnosed with AD or PD. In this regard, calcification of the pineal gland, typically seen in the third decade, has been associated with a reduction in melatonin production. Recent studies have suggested that exogenous melatonin application can be utilized to treat sleep disorders in patients with neurodegenerative diseases. Furthermore, research has shown that deficiencies in melatonin levels in patients with AD or PD begin before a diagnosis of either disease is made. These findings could encourage further research on melatonin as a potential biomarker for the diagnosis or a possible area for the early treatment of these diseases. Many clinical studies have also produced data denoting melatonin treatment as a method to reduce the detrimental neurocognitive effects of these diseases. Further research on the role of melatonin in neurodegenerative diseases could expand symptomatic and prophylactic treatment options for diseases such as AD and PD. This review investigates melatonin's physiological properties, its role in AD and PD, and current findings on its potential therapeutic benefits in AD and PD patients.

Bibliometric analysis of global research trends on regulatory T cells in neurological diseases

This bibliometric study aimed to summarize and visualize the current research status, emerging trends, and research hotspots of regulatory T (Treg) cells in neurological diseases. Relevant documents were retrieved from the Web of Science Core Collection. Tableau Public, VOSviewer, and CiteSpace software were used to perform bibliometric analysis and network visualization. A total of 2,739 documents were included, and research on Treg cells in neurological diseases is still in a prolific period. The documents included in the research were sourced from 85 countries/regions, with the majority of them originating from the United States, and 2,811 organizations, with a significant proportion of them coming from Harvard Medical School. Howard E Gendelman was the most prolific author in this research area. Considering the number of documents and citations, impact factors, and JCR partitions, Frontiers in Immunology was the most popular journal in this research area. Keywords "multiple sclerosis," "inflammation," "regulatory T cells," "neuroinflammation," "autoimmunity," "cytokines," and "immunomodulation" were identified as high-frequency keywords. Additionally, "gut microbiota" has recently emerged as a new topic of interest. The study of Treg cells in neurological diseases continues to be a hot topic. Immunomodulation, gut microbiota, and cytokines represent the current research hotspots and frontiers in this field. Treg cell-based immunomodulatory approaches have shown immense potential in the treatment of neurological diseases. Modifying gut microbiota or regulating cytokines to boost the numbers and functions of Treg cells represents a promising therapeutic strategy for neurological diseases.

Effect of neonatal melatonin administration on behavioral and brain electrophysiological and redox imbalance in rats

Introduction

Melatonin (MLT) reportedly has beneficial effects in neurological disorders involving brain excitability (e.g., Epilepsy and Migraine) and behavioral patterns (e.g., Anxiety and Depression). This study was performed to investigate, in the developing rat brain, the effect of early-in-life administration of two different doses of exogenous MLT on behavioral (anxiety and memory) and electrophysiological (CSD analysis) aspects of brain function. Additionally, brain levels of malondialdehyde (MDA) and superoxide dismutase (SOD), both cellular indicators of redox balance status, were evaluated. We hypothesize that MLT differentially affects the behavioral and CSD parameters as a function of the MLT dose.

Materials and methods

Male Wistar rats received, from the 7th to the 27th postnatal day (PND), on alternate days, vehicle solution, or 10 mg/kg/or 40 mg/kg MLT (MLT-10 and MLT-40 groups), or no treatment (intact group). To perform behavioral and cognition analysis, from PND30 to PND32, they were tested in the open field apparatus, first for anxiety (PND30) and then for object recognition memory tasks: spatial position recognition (PND31) and shape recognition (PND32). On PND34, they were tested in the elevated plus maze. From PND36 to 42, the excitability-related phenomenon known as cortical spreading depression (CSD) was recorded, and its features were analyzed.

Results

Treatment with MLT did not change the animals' body weight or blood glucose levels. The MLT-10 treatment, but not the MLT-40 treatment, was associated with behaviors that suggest less anxiety and improved memory. MLT-10 and MLT-40 treatments, respectively, decelerated and accelerated CSD propagation (speed of 2.86 ± 0.14 mm/min and 3.96 ± 0.16 mm/min), compared with the control groups (3.3 ± 0.10 mm/min and 3.25 ± 0.11 mm/min, for the intact and vehicle groups, respectively; p < 0.01). Cerebral cortex levels of malondialdehyde and superoxide dismutase were, respectively, lower and higher in the MLT-10 group but not in the MLT40 group.

Conclusion

Our findings suggest that MLT intraperitoneal administration during brain development may differentially act as an antioxidant agent when administered at a low dose but not at a high dose, according to behavioral, electrophysiological, and biochemical parameters.

Non-Excitatory Amino Acids, Melatonin, and Free Radicals: Examining the Role in Stroke and Aging

The aim of this review is to explore the relationship between melatonin, free radicals, and non-excitatory amino acids, and their role in stroke and aging. Melatonin has garnered significant attention in recent years due to its diverse physiological functions and potential therapeutic benefits by reducing oxidative stress, inflammation, and apoptosis. Melatonin has been found to mitigate ischemic brain damage caused by stroke. By scavenging free radicals and reducing oxidative damage, melatonin may help slow down the aging process and protect against age-related cognitive decline. Additionally, non-excitatory amino acids have been shown to possess neuroprotective properties, including antioxidant and anti-inflammatory in stroke and aging-related conditions. They can attenuate oxidative stress, modulate calcium homeostasis, and inhibit apoptosis, thereby safeguarding neurons against damage induced by stroke and aging processes. The intracellular accumulation of certain non-excitatory amino acids could promote harmful effects during hypoxia-ischemia episodes and thus, the blockade of the amino acid transporters involved in the process could be an alternative therapeutic strategy to reduce ischemic damage. On the other hand, the accumulation of free radicals, specifically mitochondrial reactive oxygen and nitrogen species, accelerates cellular senescence and contributes to age-related decline. Recent research suggests a complex interplay between melatonin, free radicals, and non-excitatory amino acids in stroke and aging. The neuroprotective actions of melatonin and non-excitatory amino acids converge on multiple pathways, including the regulation of calcium homeostasis, modulation of apoptosis, and reduction of inflammation. These mechanisms collectively contribute to the preservation of neuronal integrity and functions, making them promising targets for therapeutic interventions in stroke and age-related disorders.

Effect of melatonin on sleep quality and EEG features in childhood epilepsy: a possible non-conventional treatment

Background

Sleep and epilepsy are characterized by a bidirectional relationship. Indeed, epilepsy predisposes to the development of sleep disorders, while sleep deprivation may exacerbate epilepsy. In addition, antiseizure medication can disrupt normal sleep architecture. Therefore, adequate sleep hygiene could lead to improvement in seizure control. The present study aimed to evaluate the effect of melatonin on seizure frequency, EEG tracing, and sleep in children with focal idiopathic epilepsy.

Methods

This observation study evaluated the effect of 4 mg oral melatonin in ameliorating sleep-wake cycle, seizure frequency, and EEG features in children with focal idiopathic epilepsy of infancy. Twenty children were enrolled from September 2020 to August 2021. The study consisted of serial controls at enrollment (t0), at 3 months (t1), and at 6 months (t2) including neurological examination, questionnaire about sleep disturbances (CSHQ), and EEG.

Results

A significant improvement in sleep quality and daytime sleepiness was observed after melatonin supplementation. Furthermore, we observed a noteworthy improvement in EEG tracing at t2 that exhibited a significant correlation with improvements in CSHQ scores.

Conclusion

The studies conducted so far to evaluate the effect of melatonin in persons with epilepsy do not lead to definitive conclusions. Despite the small population sample and the study design, we report sleep and EEG improvement after melatonin administration in our cohort. Larger studies are needed to further study the neuroprotective and anticonvulsant properties of melatonin.

Mitochondria and Brain Disease: A Comprehensive Review of Pathological Mechanisms and Therapeutic Opportunities

Mitochondria play a vital role in maintaining cellular energy homeostasis, regulating apoptosis, and controlling redox signaling. Dysfunction of mitochondria has been implicated in the pathogenesis of various brain diseases, including neurodegenerative disorders, stroke, and psychiatric illnesses. This review paper provides a comprehensive overview of the intricate relationship between mitochondria and brain disease, focusing on the underlying pathological mechanisms and exploring potential therapeutic opportunities. The review covers key topics such as mitochondrial DNA mutations, impaired oxidative phosphorylation, mitochondrial dynamics, calcium dysregulation, and reactive oxygen species generation in the context of brain disease. Additionally, it discusses emerging strategies targeting mitochondrial dysfunction, including mitochondrial protective agents, metabolic modulators, and gene therapy approaches. By critically analysing the existing literature and recent advancements, this review aims to enhance our understanding of the multifaceted role of mitochondria in brain disease and shed light on novel therapeutic interventions.

A review of the botany, phytochemistry, traditional uses, pharmacology, toxicology, and quality control of the Astragalus memeranaceus

Astragali Radix (Huangqi) is mainly distributed in the Northern Hemisphere, South America, and Africa and rarely in North America and Oceania. It has long been used as an ethnomedicine in the Russian Federation, Mongolia, Korea, Kazakhstan, and China. It was first recorded in the Shennong Ben Cao Jing and includes the effects of reinforcing healthy qi, dispelling pathogenic factors, promoting diuresis, reducing swelling, activating blood circulation, and dredging collaterals. This review systematically summarizes the botanical characteristics, phytochemistry, traditional uses, pharmacology, and toxicology of Astragalus to explore the potential of Huangqi and expand its applications. Data were obtained from databases such as PubMed, CNKI, Wan Fang Data, Baidu Scholar, and Google Scholar. The collected material also includes classic works of Chinese herbal medicine, Chinese Pharmacopoeia, Chinese Medicine Dictionary, and PhD and Master's theses. The pharmacological effects of the isoflavone fraction in Huangqi have been studied extensively; The pharmacological effects of Huangqi isoflavone are mainly reflected in its anti-inflammatory, anti-tumor, anti-oxidant, anti-allergic, and anti-diabetic properties and its ability to treat several related diseases. Additionally, the medicinal uses, chemical composition, pharmacological activity, toxicology, and quality control of Huangqi require further elucidation. Here, we provide a comprehensive review of the botany, phytochemistry, traditional uses, pharmacology, toxicology, and quality control of Astragalus to assist future innovative research and to identify and develop new drugs involving Huangqi.

Untargeted metabonomic analysis of a cerebral stroke model in rats: a study based on UPLC-MS/MS

Introduction

Brain tissue damage caused by ischemic stroke can trigger changes in the body's metabolic response, and understanding the changes in the metabolic response of the gut after stroke can contribute to research on poststroke brain function recovery. Despite the increase in international research on poststroke metabolic mechanisms and the availability of powerful research tools in recent years, there is still an urgent need for poststroke metabolic studies. Metabolomic examination of feces from a cerebral ischemia-reperfusion rat model can provide new insights into poststroke metabolism and identify key metabolic pathways, which will help reveal diagnostic and therapeutic targets as well as inspire pathophysiological studies after stroke.

Methods

We randomly divided 16 healthy adult pathogen-free male Sprague-Dawley (SD) rats into the normal group and the study group, which received middle cerebral artery occlusion/reperfusion (MCAO/R). Ultra-performance liquid chromatography-tandem mass spectrometry (UPLCMS/MS) was used to determine the identities and concentrations of metabolites across all groups, and filtered high-quality data were analyzed for differential screening and differential metabolite functional analysis.

Results

After 1 and 14 days of modeling, compared to the normal group, rats in the study group showed significant neurological deficits (p < 0.001) and significantly increased infarct volume (day 1: p < 0.001; day 14: p = 0.001). Mass spectra identified 1,044 and 635 differential metabolites in rat feces in positive and negative ion modes, respectively, which differed significantly between the normal and study groups. The metabolites with increased levels identified in the study group were involved in tryptophan metabolism (p = 0.036678, p < 0.05), arachidonic acid metabolism (p = 0.15695), cysteine and methionine metabolism (p = 0.24705), and pyrimidine metabolism (p = 0.3413), whereas the metabolites with decreased levels were involved in arginine and proline metabolism (p = 0.15695) and starch and sucrose metabolism (p = 0.52256).

Discussion

We determined that UPLC-MS/MS could be employed for untargeted metabolomics research. Moreover, tryptophan metabolic pathways may have been disordered in the study group. Alterations in the tryptophan metabolome may provide additional theoretical and data support for elucidating stroke pathogenesis and selecting pathways for intervention.

Sex and stress hormone dysregulation as clinical manifestations of hypothalamic function in migraine disorder: A meta-analysis

Migraine is a leading cause of disability in young adults. It occurs more frequently in females, often comorbidly with stress disorders, suggesting an association with hypothalamic sex and stress hormonal function and a likely interaction with autonomic nervous system activation. Thus, this study aimed to meta-analyse current literature pertaining to female and male sex hormones (estrogen, progesterone and testosterone concentration), hypothalamic-pituitary-adrenal axis (HPA axis) cortisol responses and heart rate variability (HRV) in migraineurs and controls aged 13-65 years. A systematic search of MEDLINE, Embase, PsycINFO, PubMed, CINAHL and Web of Science databases on 29/08/2022 identified 29 studies for meta-analysis (encompassing 719 migraineur and 592 control participants) that met inclusion and NHLBI risk of bias criteria. Results demonstrated that estrogen concentrations of female migraineurs were reduced (g = -.60, 95% CI [-.91, -.29], p < .001) in the luteal phase of the menstrual cycle, compared to controls. No differences were found in progesterone levels overall in female migraineurs, nor in testosterone levels in male migraineurs compared to controls. Further, early diurnal cortisol concentrations were elevated (g = .32, 95% CI [.00, .63], p = .036) in female and male migraineurs compared to controls, though no differences were found in HRV of female or male migraineurs compared to controls. These findings of dysregulation of estrogen in females and cortisol dysregulation in female and male migraineurs indicate perturbed hypothalamic function and highlight the association of migraine with stress and the need for further rigorous investigation of hypothalamic neuroendocrine functions in migraineurs of both sexes.

Effects of graphene oxide nanoparticles administration against reserpine-induced neurobehavioral damage and oxidative stress in an animal model of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by the degeneration of substantia nigra dopaminergic neurons. Many therapeutic strategies were explored for PD with no success. In this study, we investigated the efficacy of graphene oxide nanoparticles (GONPs) using the reserpine model of PD. Low concentrations GONPs were utilized as a therapeutic agent in many neurodegenerative diseases. We assessed the neurobehavioral alterations in the reserpine model of PD and investigated the neuroprotective and antioxidant effects of GONPs in this model. Thirty male mice were separated into three groups (N = 10): C (control); Res (Reserpine 0.25 mg/kg); Res + GONPs (Reserpine 0.25 mg/kg and GONPs 25 mg/kg). Our results showed that reserpine neurotoxicity induced hypoactivity with a significant increase of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels in the brain and brainstem. GONPs reversed the reserpine-induced hypoactivity concomitant with decreased neuronal CAT and MDA levels. These findings support the potential use of GONPs as an antioxidant agent in the central nervous system (CNS) that protects against neurodegeneration in the reserpine PD model.

Melatonin regulates microglial polarization to M2 cell via RhoA/ROCK signaling pathway in epilepsy

BACKGROUND

Melatonin (MEL), an endogenous hormone, has been widely investigated in neurological diseases. Microglia (MG), a resident immunocyte localizing in central nervous system is reported to play important functions in the animal model of temporal lobe epilepsy (TLE). Some evidence showed that MEL influenced activation of MG, but the detailed model of action that MEL plays in remains uncertain.

METHODS

In this study, we established a model of TLE in mice by stereotactic injection of kainic acid (KA). We treated the mice with MEL. Lipopolysaccharide, ROCK2-knockdown (ROCK-KD) and -overexpression (ROCK-OE) of lentivirus-treated cells were used in cell experiments to simulate an in vitro inflammatory model.

RESULTS

The results of electrophysiological tests showed that MEL reduced frequency and severity of seizure. The results of behavioral tests indicated MEL improved cognition, learning, and memory ability. Histological evidences demonstrated a significant reduction of neuronal death in the hippocampus. In vivo study showed that MEL changed the polarization status of MG from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype by inversely regulating the RhoA/ROCK signaling pathway. In cytological study, we found that MEL had a significant protective effect in LPS-treated BV-2 cells and ROCK-KD cells, while the protective effect of MEL was significantly attenuated in ROCK-OE cells.

CONCLUSION

MEL played an antiepileptic role in the KA-induced TLE modeling mice both in behavioral and histological levels, and changed MG polarization status by regulating the RhoA/ROCK signaling pathway.

Melatonin reduces β-amyloid accumulation and improves short-term memory in streptozotocin-induced sporadic Alzheimer's disease model

Melatonin is a hormone secreted by the pineal gland, it can be associated with circadian rhythms, aging and neuroprotection. Melatonin levels are decreased in sporadic Alzheimer's disease (sAD) patients, which suggests a relationship between the melatonergic system and sAD. Melatonin may reduce inflammation, oxidative stress, TAU protein hyperphosphorylation, and the formation of β-amyloid (Aβ) aggregates. Therefore, the objective of this work was to investigate the impact of treatment with 10 mg/kg of melatonin (i.p) in the animal model of sAD induced by the intracerebroventricular (ICV) infusion of 3 mg/kg of streptozotocin (STZ). ICV-STZ causes changes in the brain of rats similar to those found in patients with sAD. These changes include; progressive memory decline, the formation of neurofibrillary tangles, senile plaques, disturbances in glucose metabolism, insulin resistance and even reactive astrogliosis characterized by the upregulation of glucose levels and glial fibrillary acidic protein (GFAP). The results show that ICV-STZ caused short-term spatial memory impairment in rats after 30 days of STZ infusion without locomotor impairment which was evaluated on day 27 post-injury. Furthermore, we observed that a prolonged 30-day treatment with melatonin can improve the cognitive impairment of animals in the Y-maze test, but not in the object location test. Finally, we demonstrated that animals receiving ICV-STZ have high levels of Aβ and GFAP in the hippocampus and that treatment with melatonin reduces Aβ levels but does not reduce GFAP levels, concluding that melatonin may be useful to control the progression of amyloid pathology in the brain.

Changes in the Secretion of Melatonin and Selected Adipokines during the Progression of Parkinson's Disease-Preliminary Studies

Parkinson's disease (PD) is one of the most common neurodegenerative diseases affecting elderly people. Considering the gap in the literature on melatonin and adipokine levels in PD patients at various stages of the disease, we conducted a study to investigate the levels of selected parameters in PD patients at the disease's early (ES) and advanced (AS) stages. Melatonin, leptin, adiponectin, and resistin concentrations were measured in the blood serum of 20 PD patients without dyskinesia (ES), 24 PD patients with dyskinesia (AS), and 20 healthy volunteers as a control group (CG). The data were analyzed using ANOVA. Melatonin was significantly lower in ES (p < 0.05) and higher in AS patients (p < 0.05) compared to CG. The level of leptin was increased both in ES (p < 0.001) and AS (p < 0.001) versus CG, while resistin was increased only in patients with dyskinesia (p < 0.05). Higher melatonin (p < 0.001) and resistin (p < 0.05) and lower leptin (p < 0.05) levels were found in AS versus ES. The main findings of the study include the changes in inflammatory markers' levels during PD and a surprising increase in melatonin level in dyskinesia patients. Further research is necessary, which will be aimed at modulating the secretion of melatonin and adipokines as a treatment target for PD.

Understanding light pollution: Recent advances on its health threats and regulations

The prevalence of artificial lights not only improves the lighting conditions for modern society, but also poses kinds of health threats to human health. Although there are regulations and standards concerning light pollution, few of them are based on the potential contribution of improper lighting to diseases. Therefore, a better understanding of the health threats induced by light pollution may promote risk assessment and better regulation of artificial lights, thereby a healthy lighting environment. This review is based on a careful collection of the latest papers from 2018 to 2022 about the health threats of light pollution, both epidemiologically and experimentally. In addition to summing up the novel associations of light pollution with obesity, mental disorders, cancer, etc., we highlight the toxicological mechanism of light pollution via circadian disruption, since light pollution directly interferes with the natural light-dark cycles, and damages the circadian photoentrainment of organisms. And by reviewing the alternations of clock genes and disturbance of melatonin homeostasis induced by artificial lights, we aim to excavate the profound impacts of light pollution based on accumulating studies, thus providing perspectives for future research and guiding relevant regulations and standards.

Melatonin protects human nucleus pulposus cells from pyroptosis by regulating Nrf2 via melatonin membrane receptors

Aims

This study was performed to explore the effect of melatonin on pyroptosis in nucleus pulposus cells (NPCs) and the underlying mechanism of that effect.

Methods

This experiment included three patients diagnosed with lumbar disc herniation who failed conservative treatment. Nucleus pulposus tissue was isolated from these patients when they underwent surgical intervention, and primary NPCs were isolated and cultured. Western blotting, reverse transcription polymerase chain reaction, fluorescence staining, and other methods were used to detect changes in related signalling pathways and the ability of cells to resist pyroptosis.

Results

Western blot analysis confirmed the expression of cleaved CASP-1 and melatonin receptor (MT-1A-R) in NPCs. The cultured NPCs were identified by detecting the expression of CD24, collagen type II, and aggrecan. After treatment with hydrogen peroxide, the pyroptosis-related proteins NLR family pyrin domain containing 3 (NLRP3), cleaved CASP-1, N-terminal fragment of gasdermin D (GSDMD-N), interleukin (IL)-18, and IL-1β in NPCs were upregulated, and the number of propidium iodide (PI)-positive cells was also increased, which was able to be alleviated by pretreatment with melatonin. The protective effect of melatonin on pyroptosis was blunted by both the melatonin receptor antagonist luzindole and the nuclear factor erythroid 2–related factor 2 (Nrf2) inhibitor ML385. In addition, the expression of the transcription factor Nrf2 was up- or downregulated when the melatonin receptor was activated or blocked by melatonin or luzindole, respectively.

Conclusion

Melatonin protects NPCs against reactive oxygen species-induced pyroptosis by upregulating the transcription factor Nrf2 via melatonin receptors.

Cite this article: Bone Joint Res 2023;12(3):202–211.

Application and investigation of thrombopoiesis-stimulating agents in the treatment of thrombocytopenia

Platelets, derived from a certain subpopulation of megakaryocytes, are closely related to hemostasis, coagulation, metastasis, inflammation, and cancer progression. Thrombopoiesis is a dynamic process regulated by various signaling pathways in which thrombopoietin (THPO)-MPL is dominant. Thrombopoiesis-stimulating agents could promote platelet production, showing therapeutic effects in different kinds of thrombocytopenia. Some thrombopoiesis-stimulating agents are currently used in clinical practices to treat thrombocytopenia. The others are not in clinical investigations to deal with thrombocytopenia but have potential in thrombopoiesis. Their potential values in thrombocytopenia treatment should be highly regarded. Novel drug screening models and drug repurposing research have found many new agents and yielded promising outcomes in preclinical or clinical studies. This review will briefly introduce thrombopoiesis-stimulating agents currently or potentially valuable in thrombocytopenia treatment and summarize the possible mechanisms and therapeutic effects, which may enrich the pharmacological armamentarium for the medical treatment of thrombocytopenia.

Adverse events in long-term studies of exogenous melatonin

INTRODUCTION

Exogenous melatonin is regulated as a drug in the UK and EU but is available as an over-the-counter dietary supplement in the US and Canada. In the last 15 years, melatonin use has increased rapidly in many countries, in particular, in children and adolescents who frequently have many years of continuous exposure. Despite this, the potential risks associated with extended use continue to be unclear, and there remains a lack of systematically assessed safety data from long-term prospective trials.

AREAS COVERED

This review focuses on adverse event data reported in long-term (≥6 months) prospective trials of melatonin.

METHODS

The Embase and Medline electronic databases were searched from inception to 12 September 2022 for long-term studies of melatonin, in which adverse events were systematically monitored and reported.

EXPERT OPINION

Although the reported frequency of possible adverse events associated with long-term melatonin use is low and few clinically significant adverse events have been reported, the scarcity of data from double-blind randomized placebo-controlled trials should caution against complacency. Ideally, analysis of data from large well-established research databases should be conducted to provide good quality evidence on which to base a more rigorous evaluation of the safety profile.

Contribution of Home Gardens to Sustainable Development: Perspectives from A Supported Opinion Essay

Home gardening has a long history that started when humans became sedentary, being traditionally considered an accessible source of food and medicinal plants to treat common illnesses. With trends towards urbanization and industrialization, particularly in the post-World War II period, the importance of home gardens as important spaces for growing food and medicinal plants reduced and they began to be increasingly seen as decorative and leisure spaces. However, the growing awareness of the negative impacts of agricultural intensification and urbanization for human health, food quality, ecosystem resilience, and biodiversity conservation motivated the emergence of new approaches concerning home gardens. Societies began to question the potential of nearby green infrastructures to human wellbeing, food provisioning, and the conservation of traditional varieties, as well as providers of important services, such as ecological corridors for wild species and carbon sinks. In this context. and to foster adaptive and resilient social-ecological systems, our supported viewpoint intends to be more than an exhaustive set of perceptions, but a reflection of ideas about the important contribution of home gardens to sustainable development. We envision these humble spaces strengthening social and ecological components, by providing a set of diversified and intermingled goods and services for an increasingly urban population.

Melatonin treatment improves cognitive deficits by altering inflammatory and neurotrophic factors in the hippocampus of obese mice

Overweight and obesity are associated with an increased risk of developing dementia and cognitive deficits. Neuroinflammation is one of the most important mechanisms behind cognitive impairment in obese patients. In recent years, the neuroendocrine hormone melatonin has been suggested to have therapeutic effects for memory decline in several neuropsychiatric and neurological conditions. However, the effects of melatonin on cognitive function under obesity conditions still need to be clarified. The purpose of this study was to determine whether melatonin treatment can improve cognitive impairment in obese mice. To this end, male C57BL6 mice were treated with a high-fat diet (HFD) for 20 weeks to induce obesity. The animal received melatonin for 8 weeks. Cognitive functions were evaluated using the Y maze, object recognition test, and the Morris water maze. We measured inflammatory cytokines including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-17A, and brain-derived neurotrophic factor (BDNF) in the hippocampus of obese mice. Our results show that HFD-induced obesity significantly impaired working, spatial and recognition memory by increasing IFN-γ and IL-17A and decreasing BDNF levels in the hippocampus of mice. On the other hand, melatonin treatment effectively improved all cognitive impairments and reduced TNF-α, IFN-γ, and IL-17A and elevated BDNF levels in the hippocampus of obese mice. Taken together, this study suggests that melatonin treatment could have a beneficial role in the treatment of cognitive impairment in obesity.

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.

Podoplanin: Its roles and functions in neurological diseases and brain cancers

Podoplanin is a small mucin-like glycoprotein involved in several physiological and pathological processes in the brain including development, angiogenesis, tumors, ischemic stroke and other neurological disorders. Podoplanin expression is upregulated in different cell types including choroid plexus epithelial cells, glial cells, as well as periphery infiltrated immune cells during brain development and neurological disorders. As a transmembrane protein, podoplanin interacts with other molecules in the same or neighboring cells. In the past, a lot of studies reported a pleiotropic role of podoplanin in the modulation of thrombosis, inflammation, lymphangiogenesis, angiogenesis, immune surveillance, epithelial mesenchymal transition, as well as extracellular matrix remodeling in periphery, which have been well summarized and discussed. Recently, mounting evidence demonstrates the distribution and function of this molecule in brain development and neurological disorders. In this review, we summarize the research progresses in understanding the roles and mechanisms of podoplanin in the development and disorders of the nervous system. The challenges of podoplanin-targeted approaches for disease prognosis and preventions are also discussed.

SARS-CoV-2 infection in multiple sclerosis patients: interaction with treatments, adjuvant therapies, and vaccines against COVID-19

The SARS-CoV-2 pandemic has raised particular concern for people with Multiple Sclerosis, as these people are believed to be at increased risk of infection, especially those being treated with disease-modifying therapies. Therefore, the objective of this review was to describe how COVID-19 affects people who suffer from Multiple Sclerosis, evaluating the risk they have of suffering an infection by this virus, according to the therapy to which they are subjected as well as the immune response of these patients both to infection and vaccines and the neurological consequences that the virus can have in the long term. The results regarding the increased risk of infection due to treatment are contradictory. B-cell depletion therapies may cause patients to have a lower probability of generating a detectable neutralizing antibody titer. However, more studies are needed to help understand how this virus works, paying special attention to long COVID and the neurological symptoms that it causes.

The Pathogenetic Role of Melatonin in Migraine and Its Theoretic Implications for Pharmacotherapy: A Brief Overview of the Research

Migraine is a chronic disease of global concern, regardless of socio-economic and cultural background. It most often and intensely affects young adults, especially women. Numerous mechanisms of a migraine attack have been identified (disturbances in the reaction of vessels, functions of neurotransmitters, cortical neurons, ion channels, receptors, the process of neurogenic inflammation), and many of its symptoms can be explained by activation of the hypothalamus and disturbances in its communication with other brain regions (including the brainstem). Numerous neuropeptides and neurochemical systems also play a role in migraine. One of them is melatonin, a hormone that allows the body to adapt to cyclically changing environmental and food conditions. In this article, we present the pathophysiological basis of melatonin release from the pineal gland and other tissues (including the intestines) under the influence of various stimuli (including light and food), and its role in stimulating the brain structures responsible for triggering a migraine attack. We analyze publications concerning research on the role of melatonin in various headaches, in various stages of migraine, and in various phases of the menstrual cycle in women with migraine, and its impact on the occurrence and severity of migraine attacks. Melatonin as an internally secreted substance, but also present naturally in many foods. It is possible to supplement melatonin in the form of pharmaceutical preparations, and it seems, to be a good complementary therapy (due to the lack of significant side effects and pharmacological interactions) in the treatment of migraine, especially: in women of childbearing age, in people taking multiple medications for other diseases, as well as those sensitive to pharmacotherapy.

Melatonin effect on platelets and coagulation: Implications for a prophylactic indication in COVID-19

Severe COVID-19 is associated with the dynamic changes in coagulation parameters. Coagulopathy is considered as a major extra-pulmonary risk factor for severity and mortality of COVID-19; patients with elevated levels of coagulation biomarkers have poorer in-hospital outcomes. Oxidative stress, alterations in the activity of cytochrome P450 enzymes, development of the cytokine storm and inflammation, endothelial dysfunction, angiotensin-converting enzyme 2 (ACE2) enzyme malfunction and renin–angiotensin system (RAS) imbalance are among other mechanisms suggested to be involved in the coagulopathy induced by severe acute respiratory syndrome coronavirus (SARS-CoV-2). The activity and function of coagulation factors are reported to have a circadian component. Melatonin, a multipotential neurohormone secreted by the pineal gland exclusively at night, regulates the cytokine system and the coagulation cascade in infections such as those caused by coronaviruses. Herein, we review the mechanisms and beneficial effects of melatonin against coagulopathy induced by SARS-CoV-2 infection.

An Overview of the Circadian Clock in the Frame of Chronotherapy: From Bench to Bedside

Most living organisms in both the plant and animal kingdoms have evolved processes to stay in tune with the alternation of day and night, and to optimize their physiology as a function of light supply. In mammals, a circadian clock relying on feedback loops between key transcription factors will thus control the temporally regulated pattern of expression of most genes. Modern ways of life have highly altered the synchronization of human activities with their circadian clocks. This review discusses the links between an altered circadian clock and the rise of pathologies. We then sum up the proofs of concept advocating for the integration of circadian clock considerations in chronotherapy for health care, medicine, and pharmacotherapy. Finally, we discuss the current challenges that circadian biology must face and the tools to address them.

Melatonin supplementation for the treatment of infantile spasms: protocol for a randomised placebo-controlled triple-blind trial

INTRODUCTION

Infantile spasms (IS) is a type of severe epileptic encephalopathy that occurs in infancy and early childhood. IS is characterised clinically by epileptic spasms, often accompanied by sleep disorder and abnormal circadian rhythm. The endogenous circadian rhythm disorder, in turn, can make spasms worse. Melatonin has also been found to have anticonvulsant and neuroprotective properties by adjusting the circadian rhythm. However, there are lack of relevant studies on controlling IS by using melatonin. This study aims to analyse the therapeutic effect of melatonin supplementation for the treatment of IS.

METHODS AND ANALYSIS

This is a triple-blinded (trial participant, outcome assessor and the data analyst), prospective, randomised controlled trial to be conducted in the Department of Paediatrics, The First Medical Center of Chinese PLA General Hospital, Beijing, China from November 2020. Patients (n=70) aged 3 months to 2 years with IS will be recruited in this study after receiving written consent from their parents or guardians. Patients will be randomly divided into two equal groups and treated with a combination of adrenocorticotropic hormone, magnesium sulfate and either melatonin or placebo. Clinical data from the patients in the two groups before and after the treatment will be collected and compared. The primary outcome will be assessed 2 weeks later by seizure diaries and reported as the average reduced rate of spasms frequency. Secondary outcomes include the response rate (the rate of spasms-free), electroencephalogram hypsarrhythmia assessment and the psychomotor development assessment (Denver Developmental Screening Test). Sleep quality and safety will also be assessed.

ETHICS AND DISSEMINATION

The protocol for this study was approved by the Ethics Committee of Chinese PLA General Hospital (reference number S2020-337-01) and was reported according to the Standard Protocol Items: Recommendations for Interventional Trials statement. Findings of this research will be disseminated through national and international meetings, conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2000036208.

Exogenous Melatonin Directly and Indirectly Influences Sheep Oocytes

Understanding whether and how melatonin (MT) may impact sheep oocyte development competence is central to our ability to predict how sheep oocytes will respond to artificially regulated estrus. Implanting MT can make sheep enter estrus during the non-breeding season. One study found that the blastocyst rate increased under MT treatment, while another found that the blastocyst rate decreased. Therefore, we conducted a meta-analysis of MT directly and indirectly influencing sheep oocytes. A total of 433 articles were collected from which 20 articles and 34 treatments were finally selected. A method for estimating the default value was established for the litter size analysis. We found that exogenous MT add into in vitro maturation medium was positively related to the blastocyst rate in the lab. However, subcutaneous implanting MT did not affect the in vivo ovulation rate, fertilization rate, blastocyst rate, or pregnancy rate at farm. MT did not affect the in vitro cleavage rate. However, MT improved the in vivo cleavage rate. We hypothesized that implanted MT could increase the concentration of MT in oviduct fluid in vivo, and also that in vitro MT could increase the early cleavage rate of sheep zygotes without affecting the total cleavage rate. In the analysis of oocyte apoptosis caused by injury, the results suggested that pyroptosis would be more suitable for further research. MT produces responses in all body organs, and thus implanting of MT during non-breeding seasons should consider the effect on animal welfare.

Spectroscopic, electronic structure, molecular docking, and molecular dynamics simulation study of 7-Trifluoromethyl-1H-indole-2-carboxylic acid as an aromatase inhibitor

The present work encompasses a combined experimental and theoretical investigation of the molecular structure, vibrational wavenumbers, electronic structure at the ground and electronic excited states, molecular electrostatic potential surface of 7-(Trifluoromethyl)-1H-indole-2-carboxylic acid (TICA) and possibility of the title molecule as an aromatase inhibitor using molecular docking and molecular dynamic simulations. A stable conformer has been obtained using potential energy scans by varying appropriate dihedral angles. The obtained minimum energy conformer was further optimized at the 6-311++G (d, p) basis set by applying the most accepted B3LYP functional. A good agreement between experimental and calculated normal modes of vibration has been observed. The hydrogen-bonded interaction between two monomeric units of TICA has been investigated using NBO,QTAIM, and NCI (noncovalent interactions) analysis. Molecular docking of TICA with human placental aromatase (PDB ID: 3S79) reveals the formation of polar hydrogen bonds as well as hydrophobic interactions between the ligand and the protein, right in the binding cavity. TICA satisfies all pharmacokinetic filters (Lipinski rule of five, the Veber rule, Ghose rule, Egan rule, as well as the Muegge rule) and has a high bioavailability score of 0.85. Dynamic stability of the ligand within the binding pocket of the target protein has been confirmed by 100 ns molecular dynamics simulation results. The present study provides an excellent starting point for additional in vivo research, and TICA may eventually serve as a significant therapeutic candidate for the treatment of breast cancer.

Melatonergic Receptors (Mt1/Mt2) as a Potential Additional Target of Novel Drugs for Depression

A complex pathogenesis involving several physiological systems is theorized to underline the development of depressive disorders. Depression is accompanied by circadian regulation disruption and interaction with the functioning of both central and peripheral oscillators. Many aspects of melatonin function unite these systems. The use of drugs for circadian rhythm disorders could inspire a potential treatment strategy for depression. Melatonin plays an essential role in the regulation of circadian rhythms. It exerts effect by activating two types of melatonin receptors, type 1A (MT1) and 1B (MT2). These are G-protein-coupled receptors, predominantly located in the central nervous system. MT1/MT2 agonists could be a useful treatment approach according to all three prevalent theories of the pathogenesis of depression involving either monoamines, synaptic remodeling, or immune/inflammatory events. MT1/MT2 receptors can be a potential target for novel antidepressants with impact on concentrations of neurotrophins or neurotransmitters, and reducing levels of pro-inflammatory cytokines. There is an interesting cross-talk mediated via the physical association of melatonin and serotonin receptors into functional heteromers. The antidepressive and neurogenetic effects of MT1/MT2 agonists can also be caused by the inhibition of the acid sphingomyelinase, leading to reduced ceramide, or increasing monoamine oxidase A levels in the hippocampus. Compounds targeting MT1 and MT2 receptors could have potential for new anti-depressants that may improve the quality of therapeutic interventions in treating depression and relieving symptoms. In particular, a combined effect on MT1 and/or MT2 receptors and neurotransmitter systems may be useful, since the normalization of the circadian rhythm through the melatonergic system will probably contribute to improved treatment. In this review, we discuss melatonergic receptors as a potential additional target for novel drugs for depression.

Melatonin and multiple sclerosis: antioxidant, anti-inflammatory and immunomodulator mechanism of action

BACKGROUND

Melatonin is an indole hormone secreted primarily by the pineal gland that showing anti-oxidant, anti-inflammatory and anti-apoptotic capacity. It can play an important role in the pathophysiological mechanisms of various diseases. In this regard, different studies have shown that there is a relationship between Melatonin and Multiple Sclerosis (MS). MS is a chronic immune-mediated disease of the Central Nervous System.

AIM

The objective of this review was to evaluate the mechanisms of action of melatonin on oxidative stress, inflammation and intestinal dysbiosis caused by MS, as well as its interaction with different hormones and factors that can influence the pathophysiology of the disease.

RESULTS

Melatonin causes a significant increase in the levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione and can counteract and inhibit the effects of the NLRP3 inflammasome, which would also be beneficial during SARS-CoV-2 infection. In addition, melatonin increases antimicrobial peptides, especially Reg3β, which could be useful in controlling the microbiota.

CONCLUSION

Melatonin could exert a beneficial effect in people suffering from MS, running as a promising candidate for the treatment of this disease. However, more research in human is needed to help understand the possible interaction between melatonin and certain sex hormones, such as estrogens, to know the potential therapeutic efficacy in both men and women.