Melatonin Receptor Research Articles

Relationship Between Melatonin Receptor Agonists and Parkinson's Disease.

Parkinson's disease affects millions of people worldwide, and without significant progress in disease prevention and treatment, its incidence and prevalence could increase by more than 30% by 2030. Researchers have focused on targeting sleep and the circadian system as a novel treatment strategy for Parkinson's disease. This study investigated the association between melatonin receptor agonists and Parkinson's disease, using the Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS). The target drugs were melatonin receptor agonists including ramelteon, tasimelteon, and agomelatine. Parkinson's disease cases were defined according to the Medical Dictionary for Regulatory Activities (MedDRA) 25.0; Standardized MedDRA Query (SMQ) using both the "narrow" and "broad" preferred terms (PTs) associated with Parkinson's disease. The association between melatonin receptor agonists (ramelteon, tasimelteon, and agomelatine) and Parkinson's disease was evaluated by the reporting odds ratio. Upon analyzing the data from all patients registered in the FAERS, ramelteon (ROR: 0.66, 95% confidence interval [95% CI]: 0.51-0.84) and tasimelteon (ROR: 0.49, 95% CI: 0.38-0.62) showed negative correlations with Parkinson's disease. Conversely, only agomelatine was positively correlated with Parkinson's disease (ROR: 2.63, 95% CI: 2.04-3.40). These results suggest that among the melatonin receptor agonists, ramelteon and tasimelteon are negatively correlated with Parkinson's disease. In contrast, agomelatine was shown to be positively correlated with Parkinson's disease. These results should be used in research to develop drugs for the treatment of Parkinson's disease, fully considering the limitations of the spontaneous reporting system.

Exploring the association between melatonin and nicotine dependence (Review).

Due to the addictive qualities of tobacco products and the compulsive craving and dependence associated with their use, nicotine dependence continues to be a serious public health concern on a global scale. Despite awareness of the associated health risks, nicotine addiction contributes to numerous acute and chronic medical conditions, including cardiovascular disease, respiratory disorders and cancer. The nocturnal secretion of pineal melatonin, known as the 'hormone of darkness', influences circadian rhythms and is implicated in addiction‑related behaviors. Melatonin receptors are found throughout the brain, influencing dopaminergic neurotransmission and potentially attenuating nicotine‑seeking behavior. Additionally, the antioxidant properties of melatonin may mitigate oxidative stress from chronic nicotine exposure, reducing cellular damage and lowering the risk of nicotine‑related health issues. In addition to its effects on circadian rhythmicity, melatonin acting via specific neural receptors influences sleep and mood, and provides neuroprotection. Disruptions in melatonin signaling may contribute to sleep disturbances and mood disorders, highlighting the potential therapeutic role of melatonin in addiction and psychiatric conditions. Melatonin may influence neurotransmitter systems involved in addiction, such as the dopaminergic, glutamatergic, serotonergic and endogenous opioid systems. Preclinical studies suggest the potential of melatonin in modulating reward processing, attenuating drug‑induced hyperactivity and reducing opioid withdrawal symptoms. Chronotherapeutic approaches targeting circadian rhythms and melatonin signaling show promise in smoking cessation interventions. Melatonin supplementation during periods of heightened nicotine cravings may alleviate withdrawal symptoms and reduce the reinforcing effects of nicotine. Further research is required however, to examine the molecular mechanisms underlying the melatonin‑nicotine association and the optimization of therapeutic interventions. Challenges include variability in individual responses to melatonin, optimal dosing regimens and identifying biomarkers of treatment response. Understanding these complexities could lead to personalized treatment strategies and improve smoking cessation outcomes.

Participation of Ca2+-Calmodulin-Dependent Protein Kinase II in the Antidepressant-Like Effects of Melatonin.

Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine secreted by the pineal gland during the dark phase of the photoperiod. Its main function is the synchronization of different body rhythms with the dark-light cycle. Research on melatonin has significantly advanced since its discovery and we now know that it has considerable significance in various physiological processes, including immunity, aging, and reproduction. Moreover, in recent years evidence of the pharmacological possibilities of melatonin has increased. Indoleamine, on the other hand, has antidepressant-like effects in rodents, which may be mediated by the activation of calcium-calmodulin-dependent kinase II (CaMKII) and are also related to the regulation of neuroplasticity processes, including neurogenesis, synaptic maintenance, and long-term potentiation. Remarkably, patients with major depression show decreased levels of circulating melatonin in plasma. This review presents evidence of the antidepressant-like effects of melatonin in preclinical models and the participation of CaMKII in these actions. CaMKII's role in cognition and memory processes, which are altered in depressive states, are part of the review, and the effects of melatonin in these processes are also reviewed. Furthermore, participation of CaMKII on structural and synaptic plasticity and the effects of melatonin are also described. Finally, the advantages of using melatonin in combination with other antidepressants such as ketamine for neuroplasticity are described. Evidence supports that CaMKII is activated by melatonin and downstream melatonin receptors and may be the common effector in the synergistic effects of melatonin with other antidepressants. SIGNIFICANCE STATEMENT: This review compiled evidence supporting that melatonin causes antidepressant-like effects in mice through calmodulin kinase II stimulation of downstream melatonin receptors as well as the participation of this enzyme in neuroplasticity, memory, and cognition. Finally, we describe evidence about the effectiveness of antidepressant-like effects of melatonin in combination with ketamine.

Genetic variants affect diurnal glucose levels throughout the day.

Circadian rhythms not only coordinate the timing of wake and sleep but also regulate homeostasis within the body, including glucose metabolism. However, the genetic variants that contribute to temporal control of glucose levels have not been previously examined. Using data from 420,000 individuals from the UK Biobank and replicating our findings in 100,000 individuals from the Estonian Biobank, we show that diurnal serum glucose is under genetic control. We discover a robust temporal association of glucose levels at the Melatonin receptor 1B (MTNR1B) (rs10830963, P = 1e-22) and a canonical circadian pacemaker gene Cryptochrome 2 (CRY2) loci (rs12419690, P = 1e-16). Furthermore, we show that sleep modulates serum glucose levels and the genetic variants have a separate mechanism of diurnal control. Finally, we show that these variants independently modulate risk of type 2 diabetes. Our findings, together with earlier genetic and epidemiological evidence, show a clear connection between sleep and metabolism and highlight variation at MTNR1B and CRY2 as temporal regulators for glucose levels.

The role of melatonergic system in intervertebral disc degeneration and its association with low back pain: a clinical study.

The mechanisms of intervertebral disc degeneration (IVDD) in low back pain (LBP) patients are multiples. In this study, we attempt to investigate whether melatonergic system plays a potential role in IVDD patients with LBP by analyzing their clinical specimens. The fucus will be given to the correlation between the melatonin receptor expression and intervertebral disc tissue apoptosis. In this clinical study, 107 lumbar intervertebral disc nucleus pulposus (NP) specimens from patients with LBP were collected with patients' consents. The disc height (DH) discrepancy ratio, range of motion and sagittal parameters of the pathological plane were measured and Pfirrmann grade was used to classified the grades of IVDD level. Discs at grades 1-3 were served as normal control and grades 4-5 were considered as IVDD. The expression levels of melatonin receptor 1A (MT1) and 1B (MT2) were measured by immunohistochemistry. The apoptosis of NP was assessed using TUNEL staining. Their potential associations among MT1/2, DH, apoptosis, sagittal parameters with IVDD and LBP were evaluated with statistical analysis. The incidence of IVDD was positively associated with age and negatively related to VAS scores for LBP (p<0.001). Patients with higher degree of IVDD also have higher DH discrepancy ratio (p<0.001), higher prevalence of lumbar instability (p=0.003) and higher cell apoptosis compared to the control. Nevertheless, no statistically significant correlation was identified between Pfirrmann grade and lumbar sagittal parameters. MT1 and MT2 both were highly expressed in the NP tissues. Importantly, MT1 expression but not MT2 was significantly increased in the intervertebral disc tissue of patients with IVDD and its level correlated well with cell apoptosis level and the severity of IVDD as well as lower VAS scores for LBP. The highly elevated MT1 expression was found in NP tissues of patients with IVDD and LBP compared to the control. This phenomenon probably reflects the compensating response of the body to the pathological alteration of the IVDD and LBP. Therefore, these findings provide the novel information to use selective agonists of MT1 to target IVDD and LBP clinically.

Postoperative use of sleep aids and delirium in older adults after major surgery: A retrospective cohort study.

Sleep aids are commonly prescribed to treat sleep disturbance, a modifiable risk factor for postoperative delirium in older patients. The use of melatonin receptor agonists in the postoperative period has been increasing. The comparative safety of melatonin receptor agonists, zolpidem, and temazepam remains uncertain. This retrospective study included 22,083 patients ≥65 years old who initiated melatonin receptor agonists, zolpidem, or temazepam after major surgery in the Premier Healthcare Database 2009-2018. We performed propensity score-based overlap weighting and estimated the risk ratio (RR) and risk difference (RD) of postoperative delirium as the primary outcome and a composite of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality as secondary outcomes. The mean age of the study population was 78 (SD, 7) years and 50% were female. There was no significant difference in the risk of postoperative delirium among patients treated with melatonin receptor agonists (3.4%, reference group), zolpidem (2.9%; RR [95% CI], 0.9 [0.7-1.2]; RD [95% CI] per 100 persons, -0.3 [-1.1 to 0.6]), and temazepam (3.1%; 0.9 [0.7-1.1]; RD [95% CI] per 100 persons, -0.5 [-1.2 to 0.3]). The risks of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality were also similar among all groups. Melatonin receptor agonists were not associated with a lower risk of postoperative delirium and other adverse outcomes compared with zolpidem and temazepam in older adults after major surgery.

Mitochondria of Porcine Oocytes Synthesize Melatonin, Which Improves Their In Vitro Maturation and Embryonic Development.

The in vitro maturation efficiency of porcine oocytes is relatively low, and this limits the production of in vitro porcine embryos. Since melatonin is involved in mammalian reproductive physiology, in this study, we have explored whether endogenously produced melatonin can help in porcine oocyte in vitro maturation. We have found, for the first time in the literature, that mitochondria are the major sites for melatonin biosynthesis in porcine oocytes. This mitochondrially originated melatonin reduces ROS production and increases the activity of the mitochondrial respiratory electron transport chain, mitochondrial biogenesis, mitochondrial membrane potential, and ATP production. Therefore, melatonin improves the quality of oocytes and their in vitro maturation. In contrast, the reduced melatonin level caused by siRNA to knockdown AANAT (siAANAT) is associated with the abnormal distribution of mitochondria, decreasing the ATP level of porcine oocytes and inhibiting their in vitro maturation. These abnormalities can be rescued by melatonin supplementation. In addition, we found that siAANAT switches the mitochondrial oxidative phosphorylation to glycolysis, a Warburg effect. This metabolic alteration can also be corrected by melatonin supplementation. All these activities of melatonin appear to be mediated by its membrane receptors since the non-selective melatonin receptor antagonist Luzindole can blunt the effects of melatonin. Taken together, the mitochondria of porcine oocytes can synthesize melatonin and improve the quality of oocyte maturation. These results provide an insight from a novel aspect to study oocyte maturation under in vitro conditions.

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.

The Role of Melatonin and Matrix Metalloproteinases in Breast Cancer Pathogenesis: A Comprehensive Review

Background: Breast cancer is a heterogeneous disease with molecular subtypes including Triple Negative Breast Cancer (TNBC), HER2/neu-positive, Luminal Type A, and Luminal Type B, each with unique clinical behaviors and therapeutic responses. This study investigates the role of melatonin, matrix metalloproteinases (MMPs), pro-inflammatory cytokines (IL6 and TNF-alpha), and lactate dehydrogenase (LDH) isoenzymes in breast cancer pathogenesis. Methods: Over three years, 171 breast cancer patients were studied. Blood and urine samples were collected to measure melatonin, MMPs, IL-6, TNF-alpha, LDH-1, and LDH-5 levels. Circulating tumor cells (CTCs) were isolated using density gradient centrifugation and immunomagnetic separation. Melatonin receptor expression on CTCs was analyzed by flow cytometry and immunocytochemistry. Plasma concentrations of melatonin were measured using high-performance liquid chromatography (HPLC), and MMPs, IL-6, TNF-alpha, LDH isoenzymes were quantified using enzyme-linked immunosorbent assays (ELISAs) and electrophoretic methods. Results: The expression of melatonin receptors was lowest in TNBC patients, higher in HER2/neu-positive and ER/PRnegative patients, and highest in Luminal Type A and B patients. TNBC patients exhibited elevated LDH-1 and inflammatory cytokines (IL-6, TNF-alpha), with significantly decreased melatonin levels. HER2/neu-positive patients showed elevated LDH5 and moderate decreases in melatonin. Luminal Type B and A patients had varying degrees of biomarker elevation and melatonin receptor expression. Discussion: The findings suggest a correlation between reduced melatonin signaling and aggressive breast cancer phenotypes, particularly TNBC. Elevated MMPs and pro-inflammatory cytokines underscore the role of inflammation and ECM degradation in cancer progression. Melatonin’s potential inhibitory effects on these pathways highlight its therapeutic promise. The combined assessment of melatonin, MMPs, cytokines, and LDH could guide personalized treatment strategies. Conclusion: This study underscores melatonin’s multifaceted role in breast cancer pathogenesis. Melatonin receptor expression, along with MMP, IL-6, TNF-alpha, and LDH levels, provides a detailed molecular landscape of breast cancer subtypes. Integrating melatonin supplementation into therapeutic regimens holds promise for improving outcomes, particularly inaggressive subtypes like TNBC. Further research and clinical trials are essential to validate these findings and develop effective melatonin-based therapies.

P-708 melatonin alleviates circadian rhythm disruption-induced enhanced luteinizing hormone pulsatility and ovarian dysfunction in vivo and in vitro

Abstract Study question Is melatonin deficiency a reversible cause of abnormal pattern of luteinizing hormone (LH) pulsatility and ovarian dysfunction caused by circadian rhythm disruption (CRD)? Summary answer Melatonin could rescue the augmented LH pulsatility and reproductive abnormalities caused by CRD. What is known already Melatonin, mainly synthesized and released by pineal gland, engages in regulating circadian rhythms. When circadian rhythms are disrupted, the nocturnal productions of melatonin are suppressed. Evidence suggests that circadian rhythm disruption (CRD) is associated with reproductive dysfunctions, while melatonin plays a vital role for female reproduction as a free radical scavenger and a neuroendocrine regulator. The gonadotrophin-releasing hormone (GnRH) drives pulsatile luteinizing hormone (LH) secretion, which is also essential for fertility. Study design, size, duration We used 90 CBA/CaJ mice to establish the chronic jet-lag model in which mice were exposed to an 8 hr time shift every 3 days. After 8 weeks of jet-lag induction, some of the mice were given melatonin treatment for 4 weeks. Furthermore, we used a perfusion system in vitro to mimic the process of CRD-induce high-frequency GnRH pulses stimulation of LβT2 gonadotrope cells. Participants/materials, setting, methods Repetitive tail-tip blood collection was used to evaluate the pattern of LH pulsatility. Blood plasma samples were collected from 4 mice at 4-hour intervals to measure levels of melatonin. Follicular development was evaluated by ovarian histology. Reproductive hormones was detected by ELISA. Immunohistochemistry and western blot were used to detect the expression of melatonin receptor 1A (MT1). The LβT2 cells were exposed to pulsatile GnRH at high pulse frequencies to mimic augmented pulsatile GnRH stimulation. Main results and the role of chance CRD mice exhibited reproductive-endocrine dysfunction, including irregular estrous cycles, reduced number of corpus lutea (CL), and decreased levels of estradiol and progesterone. Additionally, CRD enhanced the frequency and amplitude of LH pulsatility and pituitary LH beta-subunit expression. Melatonin administration alleviated these CRD-induced reproductive abnormalities and reversed the augmented LH pulsatility. The expression of MT1 decreased in the anterior pituitaries of CRD mice but increased after melatonin treatment, indicating the essential role of MT1 in melatonin’s reversal of CRD-induced enhanced LH pulsatility. Limitations, reasons for caution Further research is needed to validate the applicability and safety of these findings in humans. Wider implications of the findings The results suggest that melatonin may be a beneficial option for patients with reproductive-endocrine abnormalities, particularly those with circadian rhythm disruption. Trial registration number 82101719

Melatonin regulates mitochondrial function to alleviate ferroptosis through the MT2/Akt signaling pathway in swine testicular cells

Increasing evidence has shown that many environmental and toxic factors can cause testicular damage, leading to testicular ferroptosis and subsequent male reproductive disorders. Melatonin is a major hormone and plays an vital role in regulating male reproduction. However, there is a lack of research on whether Mel can alleviate testicular cell ferroptosis and its specific mechanism. In this study, the results indicated that Mel could enhance the viability of swine testis cells undergoing ferroptosis, reduce LDH enzyme release, increase mitochondrial membrane potential, and affect the expression of ferroptosis biomarkers. Furthermore, we found that melatonin depended on melatonin receptor 1B to exert these functions. Detection of MMP and ferroptosis biomarker protein expression confirmed that MT2 acted through the downstream Akt signaling pathway. Moreover, inhibition of the Akt signaling pathway can eliminate the protective effect of melatonin on ferroptosis, inhibit AMPK phosphorylation, reduce the expression of mitochondrial gated channel (VDAC2/3), and affect mitochondrial DNA transcription and ATP content. These results suggest that melatonin exerts a beneficial effect on mitochondrial function to mitigate ferroptosis through the MT2/Akt signaling pathway in ST cells.

Application of Music Therapy in Improving the Sleep Quality and Mental Health of Nurses with Circadian Rhythm Sleep Disorders Caused by Work Shifts.

To analyze the impact of using music therapy to improve the sleep quality and mental health of nurses who suffer from circadian rhythm sleep disorders. Our retrospective analysis included 360 nurses with circadian rhythm sleep disorders from 20 different departments who worked in Wuhan Third Hospital for more than 1 year from May 2022 to May 2023. A total of 180 nurses with circadian rhythm sleep disorders were classified as the control group (received melatonin receptor agonist Melatonin Receptor Type 2 [MT2]). The other 180 cases were classified into the observation group (received melatonin receptor agonist MT2 + music therapy). After six courses of treatment, the clinical efficacy, Self-Assessment Anxiety Scale (SAS) score, Self-rating Depression Scale (SDS), and Pittsburgh Sleep Quality Index Scale (PSQI) score of the two groups of nurses were compared. Before treatment, no statistically significant differences in baseline treatment and SAS, SDS, and PSQI scores were found between the two groups. After treatment, the total effective rate of treatment in the observation group was 85.56%, which was significantly higher than the 50.56% in the control group (P < 0.001). After treatment, the SAS, SDS and PSQI scores of the observation group were lower than those of the control group (P < 0.05). The SAS, SDS and PSQI scores of both groups were lower after treatment than they were before treatment (P < 0.05). Implementing music therapy for nurses with circadian rhythm sleep disorders caused by shifts can improve sleep quality and reduce negative emotions. It is a clinical strategy with clinical application value and a certain promotion value.

A probiotic NVP1704 alleviates stress-induced sleeplessness/depression-like symptoms in mice by upregulating serotonergic and GABAergic systems and downregulating NF-κB activation.

Sleeplessness (insomnia) is a potential symptom of depression. A probiotic NVP1704 alleviates depression-like behavior and neuroinflammation in mice. Therefore, to understand whether NVP1704 could be effective against sleeplessness in vivo, we exposed immobilization stress (IS) in mice, then orally administered NVP1704 for 5 days, and assayed depression/anxiety-like behavior in the open field, elevated plus maze, and tail suspension tests, sleeping latency time, and sleep duration, euthanized then by exposure to CO2, and analyzed their related biomarkers. Oral administration of NVP1704 decreased IS-induced depression/anxiety-like behavior and sleeping latency time and increased IS-suppressed sleeping duration. NVP1704 increased IS-suppressed expression of γ-aminobutyric acid (GABA), GABAA receptor α1 (GABAARα1) and α2 subunits (GABAARα2), serotonin, 5-HT receptors (5-HT1AR and 5-HT1BR), and melatonin receptors (MT1R and MT2R) in the prefrontal cortex and thalamus. NVP1704 also increased the IS-suppressed GABAARα1-positive cell population in the prefrontal cortex and decreased IS-induced corticosterone, TNF-α, and IL-6 expression and the NF-κB+Iba1+ cell population in the brain and myeloperoxidase, TNF-α, and IL-6 expression and the NF-κB+CD11c+ cell population in the colon. Based on these findings, NVP1704 may alleviate depression/anxiety/sleeplessness-like behaviors through the upregulation of serotonergic and GABAergic systems and downregulation of NF-κB activation.

Multifaceted Roles of Melatonin in Sleep Disorders

Hormone protein melatonin helps regulate the sleep–wake cycle or circadian rhythm, making it a critical substance in sleep regulation. Melatonin synthesis mainly occurs in the epiphysis of the pineal gland, although extra-pineal melatonin has been observed in other sites of the body, such as salivary glands, the gastrointestinal tract, the placenta and breast milk. Over the years, research into melatonin has shown that it has multiple roles in sleep disorders, revealing its mechanisms of action, clinical implications and therapeutic performance. In this paper, we review recent findings on the role of melatonin in sleep disorders which include insomnia, delayed sleep phase disorder (DSPD), jet lag, and shift work sleep disorder (SWSD). In addition, we report results where melatonin agonists and novel therapeutic targets have been designed and utilized to manipulate the melatonin receptors. This paper helps delineate melatonin’s role in sleep disorders from the literature, and clarify new perspectives for prevention and treatment of human health.

RETRACTION: Changes in the Expression of Melatonin Receptors Induced by Melatonin Treatment in Hepatocarcinoma HepG2 Cells.

Carbajo-Pescador S, Martín-Renedo J, García-Palomo A, Tuñón MJ, Mauriz JL, González-Gallego J. Changes in the expression of melatonin receptors induced by melatonin treatment in hepatocarcinoma HepG2 cells. Journal of Pineal Research, 2009;47: 330-338. https://doi.org/10.1111/j.1600-079X.2009.00719.x The above article, published online on 14 October 2009 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Gianluca Tosini, and John Wiley and Sons Ltd. Following publication, concerns were raised by third parties regarding Figure 5. The authors could not provide the original data for this figure, and were unable to provide a satisfactory explanation to resolve the concerns. The retraction has been agreed because of concerns that portions of the figure were duplicated, affecting the interpretation of the data and results presented. The authors disagree with this decision.

Comprehensive signal detection of delirium-associated medication using the Food and Drug Administration Adverse Event Reporting System

ObjectiveSeveral medications are associated with delirium; however, studies with adequate statistical power are limited, and it is difficult to determine the effects of the various concomitant medications used in clinical practice. Therefore, in this study, we aimed to comprehensively evaluate the safety signals of delirium-associated drugs using a spontaneous adverse event reporting system. MethodThe JAPIC AERS (Food and Drug Administration Adverse Event Reporting System pre-processed by the Japan Pharmaceutical Information Center) was used for the analysis in this pharmacovigilance study. The reporting odds ratio (ROR) for delirium was adjusted for using multivariate logistic regression analysis with sex, age, indication, and melatonin receptor agonist use, and 22 drug categories were targeted as covariates. ResultsAfter excluding patients with missing information, 7,527,568 patients were included in the study. Delirium signals were detected even after adjusting for covariates in 17 drug categories, including benzodiazepines (adjusted ROR, 1.76; 95% confidence interval [CI], 1.64–1.89), opioids (adjusted ROR, 4.42; 95% CI, 4.21–4.64), and tricyclic antidepressants (adjusted ROR, 2.44; 95% CI, 2.20–2.71). ConclusionsThese findings suggest that many drug classes, such as benzodiazepines, are independent risk factors for delirium and strengthen the evidence of an association between delirium and medications.

UP165, standardized corn leaf extract and its active component 6-methoxybenzoxazolinone induce non-rapid eye movement sleep through melatonergic and GABAergic mechanisms

The aim of this study was to investigate the sleep-promoting effects of corn leaf extract (UP165) and its active component 6-methoxybenzoxazolinone (6-MBOA), along with the underlying mechanisms in rodent models. Sleep activity in UP165 was measured by measuring sleep duration in the pentobarbital induced sleep model, and sleep quality was evaluated through electroencephalogram (EEG) analysis. In addition, the sleep mechanism was analyzed through an in vivo sleep study co-administrated with receptor antagonists. The administrations of both UP165 and 6-MBOA effectively increased sleep duration, demonstrating a 3-fold increase sleep time at 100 mg/kg UP165 and a 2.3-fold increase at 280 μg/kg 6-MBOA compared to those of the control group. The sleep-promoting effect of UP165 was also observed in the caffeine-induced insomnia model, resulting in a 71.6% increase in sleep duration. The UP165-mediated increase in sleep time was attributed to enhanced non-rapid eye movement (NREM) sleep, specifically an increase in the δ-wave sleep measured by EEG. Mechanism analysis with co-administration of competitive antagonists in vivo revealed that UP165 and 6-MBOA enhanced sleep duration through binding to gamma-aminobutyric acid type A (GABAA) and melatonin receptors. Oral administration of UP165 for 4 weeks effectively increased both gene expression and protein levels of GABAA, melatonin 1A, and melatonin 1B receptors. High-dose administration of UP165 significantly decreased the blood level of corticosterone, while concurrently increased GABA, serotonin, and melatonin levels in brain. This study highlights the potential of UP165 and 6-MBOA as edible-grade natural ingredients for sleep promotion.

Treatment strategies for insomnia in Japanese primary care physicians’ practice: A Web-based questionnaire survey

BackgroundIt is unclear how primary care physicians manage insomnia after the introduction of novel hypnotics such as orexin receptor antagonists and melatonin receptor agonists. This Web-based questionnaire survey aimed to examine treatment strategies for insomnia in Japanese primary care practice.MethodsOne-hundred-and-seventeen primary care physicians were surveyed on the familiarity of each management option for insomnia on a binary response scale (0 = “unfamiliar”; 1 = “familiar”) and how they managed insomnia using a nine-point Likert scale (1 = “I never prescribe/perform it”; 9 = “I often prescribe/perform it”). Physicians who were unfamiliar with a management option were deemed to have never prescribed or performed it.ResultsRegarding medication, most physicians were familiar with novel hypnotics. Suvorexant was the most used hypnotic, followed by lemborexant and ramelteon. These novel hypnotics averaged 4.8–5.4 points and 4.0–4.7 points for sleep onset and sleep maintenance insomnia, respectively. By contrast, most benzodiazepines were seldom used below two points. Regarding psychotherapy, only approximately 40% of the physicians were familiar with cognitive behavioral therapy for insomnia (CBT-I) and they rarely implemented it, at an average of 1.5–1.6 points. More physicians were familiar with single-component psychotherapies (i.e., relaxation, sleep restriction therapy, and stimulus control) compared to CBT-I, and 48–74% of them implemented it slightly more often, with scores ranging from 2.6 to 3.4 points.ConclusionThis study suggests that Japanese primary care physicians seldom use CBT-I to treat insomnia. In addition, they use novel sleep medications more frequently than benzodiazepines in terms of pharmacotherapy. The use and availability of CBT-I in Japanese primary care might be facilitated by: educating primary care physicians, implementing brief or digital CBT-I, and/or developing collaborations between primary care physicians and CBT-I specialists.

Beneficial effects of melatonin on boar sperm motility and kinematics are mediated by MT1 receptor

Melatonin, a hormone synthesized in various tissues, plays a crucial role in modulating sperm characteristics, yet its protective function on boar sperm remains poorly understood. This study aimed to investigate the expression and localization of melatonin-related proteins (AANAT, ASMT, MT1, MT2, and NQO2) in pig tissues, assess the impact of melatonin on pig sperm motility parameters and quality, and elucidate the underlying molecular mechanisms. Our results revealed widespread expression of AANAT, ASMT, MT1, MT2, and NQO2 proteins in pig tissues, particularly in the testis. Specific localization patterns were observed in Leydig cells, reproductive epithelium, and columnar epithelium cells in the testis and cauda epididymis. Additionally, melatonin membrane receptors MT1 and MT2 were detected in boar sperm. Melatonin treatment significantly enhanced boar sperm motility parameters and quality, particularly with 10 nM melatonin treatment. Inhibition of the MT1 receptor, but not the MT2 receptor, resulted in decreased sperm motility, highlighting the pivotal role of the MT1 receptor in mediating melatonin's effects on boar sperm. Metabolomic analysis revealed significant alterations in sperm metabolites following melatonin supplementation, particularly in amino acid metabolism. Overall, our findings provide comprehensive insights into melatonin's mechanisms in improving boar sperm quality, suggesting its potential as a therapeutic agent for enhancing male fertility.

Chronic Caffeine Consumption, Alone or Combined with Agomelatine or Quetiapine, Reduces the Maximum EEG Peak, As Linked to Cortical Neurodegeneration, Ovarian Estrogen Receptor Alpha, and Melatonin Receptor 2

RationaleEvidence of the effects of chronic caffeine (CAFF)-containing beverages, alone or in combination with agomelatine (AGO) or quetiapine (QUET), on electroencephalography (EEG), which is relevant to cognition, epileptogenesis, and ovarian function, remains lacking. Estrogenic, adenosinergic, and melatonergic signaling is possibly linked to the dynamics of these substances.ObjectivesThe brain and ovarian effects of CAFF were compared with those of AGO + CAFF and QUET + CAFF. The implications of estrogenic, adenosinergic, and melatonergic signaling and the brain-ovarian crosstalk were investigated.MethodsAdult female rats were administered AGO (10 mg/kg), QUET (10 mg/kg), CAFF, AGO + CAFF, or QUET + CAFF, once daily for 8 weeks. EEG, estrous cycle progression, and microstructure of the brain and ovaries were examined. Brain and ovarian 17β-estradiol (E2), antimullerian hormone (AMH), estrogen receptor alpha (E2Rα), adenosine receptor 2A (A2AR), and melatonin receptor 2 (MT2R) were assessed.ResultsCAFF, alone or combined with AGO or QUET, reduced the maximum EEG peak, which was positively linked to ovarian E2Rα, negatively correlated to cortical neurodegeneration and ovarian MT2R, and associated with cystic ovaries. A large corpus luteum emerged with AGO + CAFF and QUET + CAFF, antagonizing the CAFF-mediated increased ovarian A2AR and reduced cortical E2Rα. AGO + CAFF provoked TTP delay and increased ovarian AMH, while QUET + CAFF slowed source EEG frequency to δ range and increased brain E2.ConclusionsCAFF treatment triggered brain and ovarian derangements partially antagonized with concurrent AGO or QUET administration but with no overt affection of estrus cycle progression. Estrogenic, adenosinergic, and melatonergic signaling and brain-ovarian crosstalk may explain these effects.