Serum Melatonin Levels Research Articles

Dietary Supplementation with Resveratrol Attenuates Serum Melatonin Level, Pro-Inflammatory Response and Metabolic Disorder in Rats Fed High-Fructose High-Lipid Diet under Round-the-Clock Lighting.

This study aims to investigate the effect of resveratrol on systemic inflammatory response and metabolic disorder in rats fed a high-fructose high-lipid diet (HFHLD) and exposed to round-the-clock lighting (RCL). 21 adult male Wistar rats were randomly divided into 3 groups: control (group 1, n = 7); HFHLD for 8 weeks + round-the-clock lighting (RCL) (group 2, n = 7); HFHLD + RCL + Resveratrol (in a daily dose of 5 mg/kg intragastrically (group 3, n = 7). Results show that the combined effect of HFHLD and RCL reduces the serum melatonin (p < 0.001) and accelerates pro-inflammatory activities, oxidative stress, and metabolic disorder. There is a significant increase in the serum tumour necrosis factor-alpha (TNF-α) and C-reactive protein (CRP) (both p < 0.001), blood malondialdehyde-thiobarbituric acid adducts (MDA-TBA2) (p < 0.001), serum glucose (p < 0.01), insulin concentration, and the homeostatic model assessment insulin resistance (HOMA-IR) index (both p < 0.001), serum with very low-density lipoprotein (VLDL), and triacylglycerol (TAG) (both p < 0.001). At the same time, the decrease in the serum high-density lipoprotein (HDL) level (p < 0.001) is observed in the HFHLD + RCL group compared to the control. In the HFHLD + RCL + Resveratrol group, hypomelatonaemia (p < 0.001), pro-inflammatory actions, oxidative stress, and metabolic disorder were mitigated. Resveratrol can cause a significant rise in the serum melatonin and reduce serum TNF-α and CRP levels (both p < 0.001), blood MDA-TBA2 (p < 0.001), serum glucose (both p < 0.01), insulin concentration, and HOMA-IR (both p < 0.001), serum VLDL and TAG (both p < 0.001) compared to the group 2, while serum HDL level increases (p < 0.01). Resveratrol attenuates pro-inflammatory responses and prevents considerable metabolic disorder in rats fed HFHLD under RCL.

Subchronic Low-Dose Methylmercury Exposure Accelerated Cerebral Telomere Shortening in Relevant with Declined Urinary aMT6s Level in Rats

Methylmercury (MeHg) is a global pollutant with established toxic effects on the central nervous system (CNS). However, early events and early-warning biomarkers of CNS damage following exposure to low-dose MeHg are still lacking. This study aimed to investigate whether subchronic low-dose MeHg exposure had adverse effects on the cerebral telomere length, as well as serum melatonin and its urinary metabolite 6-sulfatoxymelatonin (aMT6s) in rats. Sixteen male Sprague Dawley rats were divided into two groups. Group I was the control group. In group II, rats were exposed to MeHg by gavage at a dose of 0.1 mg/kg/day for 3 months. This study revealed that MeHg exposure resulted in impairment of learning and memory ability, a slightly reduced number of neurons and an irregular arrangement of neurons in the hippocampus. It also significantly accelerated telomere shortening in the cerebral cortex, hippocampus and hypothalamus. Moreover, MeHg exposure decreased the levels of melatonin in serum and aMT6s in urine, partly by suppressing the synthesis of 5-hydroxytryptamine (5-HT) in the brain but promoted the expression of melatonin-catalyzing AANAT and ASMT. Importantly, cerebral telomere length was positively correlated with MT and aMT6s after MeHg exposure. These results suggested that the shortened telomere length in the brain may be an early event in MeHg-induced CNS toxicity, and the level of aMT6s in urine may serve as an early-warning biomarker for MeHg-induced CNS damage.

Adult Male Syrian Hamsters (Mesocricetus auratus) Exhibit Daily Oscillations in Their Serum Levels of Melatonin and Leptin As Well As in the Expression of the GnRH, GnIH, and Kisspeptin Genes

The complex neuronal and hormonal interaction between the brain and gonads controls the neuroendocrine reproductive axis. GnRH, GnIH, and kisspeptin are important neuropeptides in this relationship. Although seasonal variations of these neuropeptides have been demonstrated in photoperiodic animals, there is no clear evidence in their daily rhythms. Melatonin and leptin hormones are also two important hormones in reproductive regulation. In our study, the relationship of melatonin and leptin hormones with daily rhythm with GnIH, GnRH, and kisspeptin gene expressions and protein oscillations was examined. Adult male Syrian hamsters were exposed to the long photoperiod and at the end of the 30-day experimental period, blood and tissue samples from each group were collected at 04:00 h, 12:00 h, 20:00 h, and 00:00 h. Daily rhythms of melatonin and leptin hormones were determined by ELISA. Quantitative analysis of GnRH, GnIH, Kisspeptin, and β-actin genes was performed with the corresponding primers in Real-Time PCR. Protein expressions were determined by the Western Blot technique. Serum melatonin and leptin levels showed an inverse rhythmic relationship. Leptin level was found to be low while melatonin was high in the dark. Daily rhythms were observed in GnIH, GnRH, and kisspeptin mRNA expressions and protein oscillations. As a result, our findings could imply that all of the relationships between melatonin, leptin, GnIH, GnRH, and kisspeptin are not reproductive, but rather metabolic in nature.

Study on the effect of Chamomile extract on melatonin hormone levels in subjects suffering from insomnia and anxiety

Introduction and Aim: Insomnia and anxiety are the most common among the psychiatric disorders. These disorders have been associated to melatonin levels; an endocrine hormone produced by the pineal gland in brain. Melatonin has also been associated to several metabolic processes in the body. In this study we aimed to investigate into the effect of chamomile extract on serum melatonin levels as well as on various other blood parameters. Materials and Methods: Fifty randomized subjects were orally treated with chamomile extract (15% w/v daily) for 8 weeks. Liver enzymes, urea, creatinine, and lipid profile were measured to see the effect of chamomile extract on the body. Results: From the results, we found a significant increase in the melatonin levels after treatment with chamomile extract. We also did not observe any rise in the liver enzyme levels, blood urea and serum creatinine. Also we found decrease in cholesterol and triglyceride levels. Conclusion: This study suggests that chamomile extract can be a natural and safe nutritional strategy for improving sleep duration and quality and in improving the lipids levels.

ВЛИЯНИЕ МЕЛАТОНИНА НА ДИНАМИКУ МАССЫ ТЕЛА И УРОВЕНЬ БЕЛКА КЛОТО В КРОВИ У ЖИВОТНЫХС ПРЕЖДЕВРЕМЕННЫМ СТАРЕНИЕМ, ВЫЗВАННЫМТЕМНОВОЙ ДЕПРИВАЦИЕЙ

On the model of premature aging induced by 30-day dark deprivation (light-dark cycle 24/0 h, artificial illumination 300 Lux), the effect of exogenous melatonin (0.3 mg/kg, 14 days after the cancellation of dark deprivation, intragastric dailyin 2 % starch mucus) on the dynamics of body weight and the level of Klotho protein in the blood was studied in outbred white male rats of 4 months of age. It has been shown that prolonged dark deprivation is accompanied by a statistically significantdecrease in the content of the Klotho protein in the blood serum, which is a marker of premature aging. Metabolic disorders associated with a statistically significant decrease in the level of melatonin and Klotho protein in the blood were expressedin fluctuations in the dynamics and rate of body weight gain in animals. At the same time, exogenous melatonin had a protective effect on the condition of animals –it contributed to an increase in the content of Klotho protein in the blood serum and restoredthe level of melatonin to the values of the negative control indicator.

A Reduced Tryptophan Diet in Patients with Diarrhoea-Predominant Irritable Bowel Syndrome Improves Their Abdominal Symptoms and Their Quality of Life through Reduction of Serotonin Levels and Its Urinary Metabolites.

(1). An essential component of any treatment for patients with irritable bowel syndrome (IBS) is an adequate diet. Currently, a low FODMAP diet is recommended as a first-line therapy, but it does not relieve abdominal discomfort in all patients, and alternative nutritional treatment is required. The purpose of this study was to evaluate the effect of a tryptophan-lowering diet (TRP) on abdominal and mental symptoms in patients with irritable bowel syndrome with predominant diarrhea (IBS-D). (2). The study included 40 patients with IBS-D, and 40 healthy subjects served as a baseline for IBS-D patients, after excluding comorbidities. The TRP intake was calculated using the nutritional calculator. The severity of abdominal symptoms was assessed using the gastrointestinal symptom rating scale (GSRS-IBS). Mental state was assessed using the Hamilton anxiety rating scale (HAM-A), the Hamilton depression rating scale (HAM-D), and the insomnia severity index (ISI). The serum levels of serotonin and melatonin and the urinary excretion of their metabolites 5-hydroxyindoleacetic acid (5-HIAA) and 6-sulfatoxymelatonin (aMT6) were determined by the ELISA method. The severity of symptoms and laboratory data were analyzed before and after a 12 week diet with tryptophan restricted to a daily dose 10 mg per kilogram body weight. (3). Compared to the control group, patients with IBS-D had a higher serum level of serotonin (198.2 ± 38.1 vs. 142.3 ± 36.4 ng/mL; p < 0.001) but a similar level of melatonin (8.6 ± 1.1 vs. 9.4 ± 3.0 pg/mL; p > 0.05). The urinary excretion of 5-HIAA was also higher in patients with IBS-D patients (7.7 ± 1.5 vs. 6.0 ± 1.7 mg/24 h; p < 0.001). After nutritional treatment, both the serum serotonin level and the urinary 5-HIAA excretion significantly decreased (p < 0.001). The severity of the abdominal symptoms and anxiety also decreased, while the HAM-D score and the ISI score remained unchanged (4). Lowering the dietary intake of tryptophan may reduce abdominal complaints and does not alter the mental state of IBS-D patients.

Disruption of regulatory mechanisms as a stress factor for patients with metabolic syndrome

Introduction. Throughout history, humanity has lived and developed in accordance with its biological rhythms, which provided the adaptation of the body to the factors of external and internal environment, ensuring the normal synchronous functioning of all its components.The purpose of this work was to study the stressful influence of circadian rhythms disturbance on patients with metabolic syndrome (MS) under conditions of dark deprivation.Material and methods of investigation. We selected patients with MS and disturbed circadian rhythms – a total of 102 people (all men) from among those who constantly work at night, in whom a decrease in melatonin levels was recorded at the preliminary stage. According to the set objectives, 102 patients (young age according to WHO criteria) were divided into three groups of 33, 37 and 32 persons according to the criterion "duration of influence of dark deprivation and MS history duration": 0–5, 5–10 and over 10 years. In the first group the mean age was 30.1 ± 1.4 years, in the second group – 36.5 ± 1.5 years, in the third group the mean age did not exceed 40.3 ± 0.9 years. Melatonin levels (as confirmation of circadian rhythm disturbances) in blood serum were studied in all study participants using Melatonin ELISA immunoassay kit (IBL, Germany). Results and discussion. Normally, when blood cortisol is measured before 10 a.m., its average value varies in a wide range from138 to 635 nmol/l. The increase up to 700 nmol/l is admitted, which is regarded as a negative influence of external factors during the examination. However, one should keep in mind that during evening measurements, cortisol levels in men may normally decrease to 80 nmol/l.Conclusions. Thus, dark deprivation in patients with metabolic syndrome leads to the formation of a stress response. Maximum changes occur after 10 years of disturbance of regulatory mechanisms and lead to a pronounced imbalance between the sympathetic and parasympathetic nervous system, increased vascular tone and changes in the profile of blood pressure during the day towards the predominance of Non-dippers and Night-peers, which increases the risk of progression of metabolic syndrome symptoms.

Influence of photoperiod variations on the mRNA expression pattern of melatonin bio-synthesizing enzyme genes in the pineal organ and retina: A study in relation to the serum melatonin profile in the tropical carp Catla catla.

Surface-dwelling C. catla were exposed to different photoperiods (8L:16D, 12L:12D, 12D:12L and 16L:8D) and the mRNA level profile of enzymes involved in melatonin synthesis was evaluated in the pineal gland and retina. Furthermore, a comparative analysis of the serum melatonin profile with the mRNA level was also performed. The results indicated diurnal variations in the transcripts of tph1, aanat and hiomt in the pineal organ and retina, and these variations change with the change in lighting regime. The serum melatonin profile showed rhythmicity in the natural photoperiod, but the serum melatonin level increased proportionally with increasing daylength. In short photoperiods, the peak value (though lower than in long photoperiods) of melatonin maintains a longer duration in serum. Moreover, the comparative analysis revealed a similar profile of mRNA of pineal aanat1 and aanat2 with serum melatonin under the same lighting conditions. This indicates that serum melatonin is produced by the pineal gland. Our results specify the importance of day length and the timing of onset or offset of the dark for maintaining the oscillating levels of serum melatonin and mRNA levels of melatonin biosynthesizing enzyme genes in the pineal organ and retina as well. The findings in this study highlight the distinctive pattern of mRNA levels in the pineal organ and retina under different photoperiods. The pineal melatonin biosynthesizing enzyme genes showed a similar pattern with serum melatonin levels while the retinal genes changed dramatically with photoperiod. We also revealed a light-dependent transcriptional regulation of pineal aanat genes in C. catla. Moreover, our results suggest that ALAN and skyglow can influence the levels of serum melatonin and its biosynthesis, resulting in desynchronization of the entire biological clock as well as the overall physiology of the animal.

Photoperiod-independent diurnal feeding improved the growth and feed utilization of juvenile rainbow trout (Oncorhynchus mykiss) by inducing food anticipatory activity

A three-month culture experiment was designed to assess the effects of photoperiod and feeding regime on growth, feed utilization, and food anticipatory activity (FAA) of juvenile rainbow trout. The experiment included two photoperiods: 24L:0D (LL) and 12L:12D (LD); three feeding regimes: random feeding (R), mid-dark stage feeding (D), and mid-light stage feeding (L). A total of six treatment groups (R-LL, D-LL, L-LL, R-LD, D-LD, L-LD) were defined. The experimental results showed that the growth and feed utilization of the scheduled feeding groups (D and L groups) were significantly higher than those of the R group under both photoperiods, and there was no statistical difference between the D and L groups. A typical FAA was observed in the L group, independent of the photoperiod. Also, the digestive enzyme activity of the L group was synchronized by the feeding time under both photoperiods. There were rhythms in serum levels of glucose (GLU), triglyceride (TG), and total-cholesterol (T-CHO) in the D and L groups. Serum GLU also had a rhythm in the R group, but the peaks occurred at the feeding point (LL group) or after the feeding point (LD group), reflecting a possible passive rise in GLU after feeding. Serum cortisol was higher in the R group than in the scheduled feeding group, indicating that random feeding caused stress to juvenile rainbow trout. Serum insulin levels were found to increase before feeding in all three feeding regimes, probably reflecting the anticipation of food induced by the last meal. Serum melatonin levels were suppressed by the LL group. Serum 5-HT levels were synchronized by meal time in the R and L groups. Finally, rhythms of appetite-related genes were observed under all three feeding regimes, and more genes were rhythmic under LL, suggesting that food can strongly synchronize the feeding rhythm of juvenile rainbow trout when lacking light zeitgeber. In summary, this study concluded that diurnal feeding (L group) independent of photoperiod induced typical FAA in juvenile rainbow trout and that the LD (12L:12D) photoperiod and L (mid-light phase) feeding were recommended in the juvenile rainbow trout aquaculture.

Effect of platelet-rich plasma combined with tranexamic acid in the treatment of melasma and its effect on the serum levels of vascular endothelial growth factor, endothelin-1 and melatonin.

To investigate the effect of platelet-rich plasma (PRP) combined with tranexamic acid (TXA) in the treatment of melasma and its effect on the serum levels of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) and melanin stimulating hormone (MSH). We retrospectively analyzed clinical data of 80 patients with melasma treated in our hospital from January 2020 to June 2021. Patients (n=38) in the control group received simple oral TXA treatment. Patients (n=42) in the study group received PRP combined with oral TXA treatment. We assessed the treatment effects on the serum biochemical index levels, the adverse reactions, and the recurrence rates in the two groups. The total efficacy of the study group (90.48%) was higher than that of the control group (73.68%) (p<0.05). After the treatment, the levels of serum VEGF increased and the levels of ET-1 and MSH decreased in both groups, but the changes in the study group were more pronounced than those in the control group (p<0.05). We found similar incidences of the adverse reaction in the study group (7.14%) and the control group (5.26%; p>0.05). The disease recurrence rates between the two groups three months after the treatment were similar (p>0.05). However, the disease recurrence rate in the study group (4.76%) was lower than that in the control group (21.05%) 6 months after treatment (p<0.05). PRP combined with oral TXA can improve the treatment effect of TXA alone in the treatment of melasma, maintaining normal levels of VEGF, ET-1 and MSH, reducing disease recurrences.

Association of melatonin and glutathione peroxidase enzyme in patients with type 2 diabetes mellitus

Diabetes mellitus (DM) is a group of diseases characterized by high blood glucose levels resulting from a defect in the body’s ability to produce and/or use insulin. It is believed that oxidative stress plays important role in the development of vascular complications in type 2 diabetes. The objectives: to determine the serum concentrations of endogenous melatonin and glutathione peroxidase (GPx) in cases of Type 2 DM and compare it with normal controls and to assess the correlation between melatonin and GPx. A case control study was done on 70 patients with diabetes mellitus type 2 according to ADA definition of DM type 2 recruited from Al Imamain Al-Kathemeaain medical city, Baghdad, Iraq who compared with 70 age, BMI and gender matched healthy control group in the levels of serum melatonin, serum glutathione peroxidase (GPx), fasting blood glucose (FBG) level, glycated hemoglobin (HbA1c), lipid profile, serum urea and serum creatinine. The activities of GPX enzyme (5.3021±1.2098) were significantly (p=0.037) lower than those of controls (6.6185±2.06877) which is accompanied with a significant reduction in the melatonin levels in patients (13.7652±2.75756) comparing with controls (17.3398±2.80153) with a significant positive correlation between GPX activity and melatonin levels in both patients and control groups. Inconclusions; melatonin levels showed to be reduced significantly in diabetic patient which may play an essential role in reducing the defense mechanism against ROS via affecting the activity of GPx enzyme.

The role of melatonin in the development of postmenopausal osteoporosis.

Melatonin is an important endogenous hormone that modulates homeostasis in the microenvironment. Recent studies have indicated that serum melatonin levels are closely associated with the occurrence and development of osteoporosis in postmenopausal women. Exogenous melatonin could also improve bone mass and increase skeletal strength. To determine the underlying mechanisms of melatonin in the prevention and treatment of postmenopausal osteoporosis, we performed this review to analyze the role of melatonin in bone metabolism according to its physiological functions. Serum melatonin is related to bone mass, the measurement of which is a potential method for the diagnosis of osteoporosis. Melatonin has a direct effect on bone remodeling by promoting osteogenesis and suppressing osteoclastogenesis. Melatonin also regulates the biological rhythm of bone tissue, which benefits its osteogenic effect. Additionally, melatonin participates in the modulation of the bone microenvironment. Melatonin attenuates the damage induced by oxidative stress and inflammation on osteoblasts and prevents osteolysis from reactive oxygen species and inflammatory factors. As an alternative drug for osteoporosis, melatonin can improve the gut ecology, remodel microbiota composition, regulate substance absorption and maintain metabolic balance, all of which are beneficial to the health of bone structure. In conclusion, our review systematically demonstrates the effects of melatonin on bone metabolism. Based on the evidence in this review, melatonin will play a more important role in the diagnosis, prevention and treatment of postmenopausal osteoporosis.

Prevalence of Insomnia among Emergency Doctors and their Physiological Link with Serum Melatonin: Key to Better Sleep among Doctors of LUMHS

Background: As a consequence of the epidemic, health care workers have been subjected to unusual levels of stress, anxiety, and sleep issues. Chronic insomnia is usually linked to circadian rhythm abnormalities. Insomnia is a frequent indication of a lack of serum melatonin. Objective: To detect the prevalence of Insomnia among doctors at LUMHS and their physiological role with regard to serum melatonin levels. Methodology: This cross-sectional study was conducted involving 116 doctors, out of which male 48(41.3%) and female 68 (58.6%), working in all clinical wards of Liaquat University of Medical &amp; Health Sciences, Jamshoro / Hyderabad from August 2021 to February 2022. Each patient's demographic information was collected. Serum Melatonin levels in the blood were measured using an ELISA KIT. Along with (Insomnia severity index) questioner was filled out by each participant. SPSS version 26 was used to analyze the collected data. Results: This study found that physicians' sleep and wake cycles are disrupted owing to their long, stressful working hours, out of 116 participants, 42.68 percent experienced insomnia. Regardless of age, gender, or BMI, Insomnia was shown to be co- related with a lower blood melatonin level (r value=-.585**, p=0.001). Conclusion: The findings of this investigation are in line with our hypothesis that reduced serum Melatonin levels in insomniacs lead to delayed signal transduction, causing circadian oscillator system anomalies. We have found that insomnia among doctors shows significant variations in relation to department, sex, designation, and working hours. Further addressing it requires molecular studies. Keywords: Insomnia, Prevalence, Serum Melatonin, sleep disturbance

Intervention Effects of Okra Extract on Brain-Gut Peptides and Intestinal Microorganisms in Sleep Deprivation Rats.

Objective Okra, possessing various bioactive components, is used to treat different diseases. This study sought to estimate the intervention effects of okra extract (OE) on brain-gut peptides (BGPs) and intestinal microorganisms in sleep deprivation (SD) rats. Methods SD rat models were established using the modified multiple platform method and then treated with normal saline, diazepam tablets, or different doses of OE. Body weight and average daily water consumption of rats were recorded. Depressive behaviors of rats were assessed by the open field test and sucrose preference test. Serum levels of noradrenaline, melatonin, inflammatory factors (IL-1β/IL-6/TNF-α/IL-4/IL-10), and BGP indexes, including gastrin (GAS), motilin (MTL), 5-hydroxytryptamine (5-HT), cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were measured by ELISA. Additionally, the DNA relative contents of representative intestinal microorganisms in the collected rat feces were determined using RT-qPCR. Results SD decreased body weight and average daily water consumption and induced depressive behaviors as well as stress and inflammatory responses in rats. SD rats exhibited lowered GAS, MTL, 5-HT, and VIP but elevated CCK and showed diminished DNA relative contents of Bacteroidetes and probiotics (Bifidobacteria and Lactobacilli) but increased Clostridium perfringens. OE at different doses ameliorated the depressive behaviors and mitigated the stress and inflammatory responses in SD rats, raised the serum contents of GAS, MTL, 5-HT, and VIP, reduced CCK level, elevated the DNA relative contents of Bacteroidetes and probiotics, but diminished Clostridium perfringens. OE exhibited similar intervention effects to diazepam tablets (positive control). Conclusion OE exerts intervention effects on BGPs and intestinal microorganisms in SD rats.

Light wavelength and its impact on broiler health

Light is a powerful management tool in poultry production systems, affecting productivity, physiology, and behavior. The objective of this study was to understand the impacts of three light colors (blue, green, or white) on broiler health. Broilers (N = 14,256) were raised in floor pens with fresh litter from 0 to 35 d in 9 rooms (2 blocked trials). Additionally, 2 genotypes (Ross YPMx708 and EPMx708) and sex were studied (6 room replications per lighting treatment and 18 pen replicates per sex × genotype × lighting program). Blood samples and tissue samples from the retina and the pineal gland were collected from birds (16–18 d of age) 9 times in one 24-hr period per trial, then analyzed to determine melatonin levels (pg/mL). Mobility was assessed via gait scoring, using a 0 to 5 scale at 31 to 32 d of age. Footpad dermatitis was assessed using a 0 to 4 scale, and litter quality by a subjective scoring system (scores ranging from 0–4). Mortality and morbidity causes were identified through necropsies performed by pathologists. Data were analyzed as a 3 × 2 × 2 factorial design, with trial as a random variable block and lighting treatment nested within rooms (MIXED procedure, SAS). Birds raised under blue light had lower serum melatonin levels during one time-point during the scotophase, but no other differences were noted. No effect of light color was observed for melatonin produced in the tissues, nor mobility and footpad dermatitis. An interaction was noted for litter quality where a higher percentage of pens housing YPM-708 broilers had litter categorized into dry, but not easily moved with the foot (category 1). Males had higher incidence of infectious and metabolic deaths than females. Interactions were observed between light and sex, where males raised under white light had a higher incidence of skeletal causes of mortality. Overall, the results showed that light color had minor impacts only on melatonin levels, mobility, footpad dermatitis, litter quality, and cause of mortality.

Melatonin improves cardiac remodeling and brain-heart sympathetic hyperactivation aggravated by light disruption after myocardial infarction.

Light in the external environment might affect cardiovascular function. The light disruption seems to be related to changes in cardiovascular physiological functions, and disturbing light may be a risk factor for cardiovascular diseases. Prior studies have found that light disruption after myocardial infarction (MI) exacerbates cardiac remodeling, and the brain-heart sympathetic nervous system may be one of the key mechanisms. However, how to improve light-disrupted cardiac remodeling remains unclear. Melatonin is an indoleamine secreted by the pineal gland and controlled by endogenous circadian oscillators within the suprachiasmatic nucleus, which is closely associated with light/dark cycle. This study aimed to explore whether melatonin could improve light-disrupted cardiac remodeling and modulate the brain-heart sympathetic nervous system. Our study revealed that light disruption reduced serum melatonin levels, aggravated cardiac sympathetic remodeling, caused overactivation of the brain-heart sympathetic nervous system, exacerbated cardiac dysfunction, and increased cardiac fibrosis after MI, while melatonin treatment improved light disruption-exacerbated cardiac remodeling and brain-heart sympathetic hyperactivation after MI. Furthermore, RNA-Seq results revealed the significant changes at the cardiac transcription level. In conclusion, melatonin may be a potential therapy for light-disrupted cardiac remodeling.

Temporal profile of serum melatonin levels in paediatric pineal tumours subjected to surgery: newer insights.

Pineal tumours (PTs) are rare and histologically variable. Serum melatonin is a well-known product of this gland, albeit with uncertain clinical implications vis-à-vis its utility as a potential tumour marker. In particular, the temporal profile of serum melatonin during the disease course remains unclear and infrequently studied. Ten children with pineal tumours were prospectively studied over 2years. Midnight serum melatonin levels were estimated before and after surgery (6-week postoperatively) and at the time of clinical-radiological progression. Different clinical, radiological, histological and treatment variables were correlated with the mean change in the pre- and postoperative serum melatonin levels using statistical methods. Histopathologically, 5 of these cases (50%) were pineal cell tumours, while the rest were tumours of non-pineal cell origin. The mean preoperative serum melatonin level was 94.9pg/ml (range 20-397pg/ml), while the mean postoperative level was 69.6pg/ml (range 45-156pg/ml; in one case, the levels became non-detectable). Tumour histology (p = 0.04) and gender (p = 0.03) correlated with high preoperative serum levels. While the change in overall mean value did not have any statistical significance (effect size 0.29, p value 0.340), postoperative serum melatonin elevation was significant in tumours of non-pineal cell origin (large effect size 0.93, p value 0.004). The serum melatonin may be affected by age, gender and symptom duration. However, the dynamic of serum melatonin in the perioperative period is largely dependent on the cell of origin of the PT.

Nocturnal urine 6-hydroxy sulfate melatonin is associated with the outcome of subjects with sepsis

Abstract Background It is imperative to identify potential biomarkers for early diagnosis and intervention of severe sepsis. This study investigated the relationship between melatonin secretion and outcome of sepsis after 28-day admission. Methods Patients with sepsis were randomly divided into an eye mask group and a control group. Blood and urine samples were collected from day 0 to 4. Relevant clinical data and 28-day survival data were obtained. Serum melatonin and urine 6-hydroxy sulfate melatonin (6-SMT) levels were measured. Results The outcome of sepsis did not differ between the eye mask and control groups. Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores were significantly higher and monocyte human leukocyte antigen-DR (mHLA-DR), serum melatonin, nocturnal urine 6-SMT, and 24-hour urine 6-SMT levels were significantly lower in the nonsurvivors than in the survivors. The outcome at day 28 after admission was significantly associated with APACHE II and SOFA scores and mHLA-DR, nocturnal urine 6-SMT, and 24-hour urine 6-SMT levels. The areas under the receiver operating characteristic curve were 0.785, 0.740, 0.774, and 0.858 for APACHE II score, SOFA score, mHLA-DR expression, and nocturnal urine 6-SMT amount, respectively. The optimal thresholds for mHLA-DR and nocturnal urine 6-SMT were 30.13% and 43.60%, respectively. Nocturnal urine 6-SMT level was significantly and positively correlated with mHLA-DR expression. Conclusion Nocturnal urine 6-SMT level may be a feasible biomarker to predict the outcome of patients with sepsis. The use of a night-time eye mask has no significant effect on the outcome of sepsis. Clinical trials This study was registered at clinicaltrials.gov (NCT02304224).

Acupoint compatibility effect and mechanism of Shenmen (HT7) and Sanyinjiao (SP6) in improving daytime fatigue and sleepiness of insomnia

To observe the acupoint compatibility effect of Shenmen (HT7) and Sanyinjiao (SP6) in improving daytime fatigue and sleepiness of insomnia, and its mechanism in regulating hypothalamic-pituitary-adrenal (HPA) axis and suprachiasmatic nucleus-pineal gland-melatonin (SCN-PG-MT) system. Ninety patients with insomnia were randomly divided into HT7, SP6 and HT7-SP6 (HT7 plus SP6) groups, with 30 cases in each group. Electroacupuncture (EA,5 Hz/25 Hz) was applied to HT7, SP6 or HT7-SP6 in each group for 30 min. The EA treatment was conducted once daily, 5 days a week for 2 weeks. Before and after treatment, the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were observed, separately. The contents of serum adrenocorticotrophic hormone (ACTH), cortisol (CS) and melatonin (MT) were detected by ELISA. Compared with before treatment, the sleep quality, sleep time, sleep efficiency, sleep disturbance, daytime dysfunction scores and total score of PSQI in the three groups after treatment were decreased (P<0.05), the time to fall asleep score of PSQI and total score of ESS were decreased in the SP6 and HT7-SP6 groups (P<0.05). After treatment, the sleep quality, time to fall asleep, sleep efficiency, daytime dysfunction scores, total score of PSQI and total score of ESS in the HT7-SP6 group were lower than those in the HT7 group (P<0.05), the sleep quality, sleep efficiency and total score of PSQI in the SP6 group were lower than those in the HT7 group (P<0.05). Compared with before treatment, the serum ACTH and CS levels in the three groups were decreased (P<0.05), and the serum MT levels in the SP6 and HT7-SP6 groups were increased (P<0.05). After treatment, the ACTH and CS levels in the HT7-SP6 group were lower than those in the HT7 group (P<0.05), and the serum MT levels in the SP6 and HT7-SP6 groups were higher than that in the HT7 group (P<0.05). The compatibility of HT7 and SP6 has a synergism effect on the improvement of night sleep quality and daytime fatigue and sleepiness of insomnia patients, the mechanism may be related with its function in down-regulating the serum ACTH and CS levels and increasing the serum MT content. SP6 has a better effect than HT7, and plays a major role in acupoint compatibility.

Gene expression profile associated with Asmt knockout-induced depression-like behaviors and exercise effects in mouse hypothalamus.

Sleep disorder caused by abnormal circadian rhythm is one of the main symptoms and risk factors of depression. As a known hormone regulating circadian rhythms, melatonin (MT) is also namely N-acetyl-5-methoxytryptamine. N-acetylserotonin methyltransferase (Asmt) is the key rate-limiting enzyme of MT synthesis and has been reportedly associated with depression. Although 50–90% of patients with depression have sleep disorders, there are no effective treatment ways in the clinic. Exercise can regulate circadian rhythm and play an important role in depression treatment. In the present study, we showed that Asmt knockout induced depression-like behaviors, which were ameliorated by swimming exercise. Moreover, swimming exercise increased serum levels of MT and 5-hydroxytryptamine (5-HT) in Asmt knockout mice. In addition, the microarray data identified 10 differentially expressed genes (DEGs) in KO mice compared with WT mice and 29 DEGs in KO mice after swimming exercise. Among the DEGs, the direction and magnitude of change in epidermal growth factor receptor pathway substrate 8-like 1 (Eps8l1) and phospholipase C-β 2 (Plcb2) were confirmed by qRT-PCR partly. Subsequent bioinformatic analysis showed that these DEGs were enriched significantly in the p53 signaling pathway, long-term depression and estrogen signaling pathway. In the protein–protein interaction (PPI) networks, membrane palmitoylated protein 1 (Mpp1) and p53-induced death domain protein 1 (Pidd1) were hub genes to participate in the pathological mechanisms of depression and exercise intervention. These findings may provide new targets for the treatment of depression.