GABA mechanisms and sleep

Exploring the mechanism of action of Bailemian capsule in the treatment of insomnia based on metabolomics, 16S rRNA with UPLC-QE-Orbitrap-MS/MS

Bailemian capsule (BLMC) is composed of lily bulb, thorny Acanthopanax root, and other traditional Chinese medicines; it is commonly used to treat insomnia in traditional Chinese medicine. However, the active ingredients and mechanisms of action that underlie this treatment ability have not been fully explored. Here, a liquid chromatography-tandem mass spectrometry method was developed to qualitatively analyse the exogenous BLMC components that directly entered the blood and several brain regions after administration of BLMC to mice. A total of 47 compounds that directly entered the blood, including isoleucine. Moreover, there were 33, 34, 36, and 27 compounds distributed in the hypothalamus, hippocampus, frontal cortex, and temporal cortex of the mice, respectively. Subsequently, this study integrated network pharmacology, metabolomics and gut microbiota analysis to explore potential mechanism of BLMC against insomnia. The network pharmacology results suggest that BLMC affects insomnia by modulating the glutamatergic synaptic pathway. And serum and hypothalamic metabolomics analysis indicates that BLMC mainly regulates the metabolic pathways of D-Glutamine and D-Glutamic acid metabolism, significantly upregulating the differential metabolite glutamic acid and downregulating glutamine. In addition, analysis of gut microbiota indicates a close relationship between norank_f_Desulfovibirosaceae and glutamic acid. This study systematically revealed for the first time the potential pharmacological components of BLMC in treating insomnia, and explored its mechanism of action from multiple perspectives, laying the foundation for further exploration of the mechanism of BLMC in treating insomnia.

Aminoacetone is associated with sleep latency

INTRODUCTION

This study conducted a targeted analysis of metabolites involved in inflammatory, oxidative stress, and neuronal pathways that were previously implicated with sleepiness based on our prior work identifying metabolites in these pathways in persons with OSA. We examine associations between sleep latency (based on the Pittsburgh Sleep Quality Index) which is an important indicator of sleep quality and daytime sleepiness, and metabolic concentrations to identify potential mechanisms linking the two.

METHODS

This cross-sectional study included 88 participants newly diagnosed and untreated for OSA who underwent an overnight in-lab or at home sleep study recruited from the Emory Mechanisms of Sleepiness Symptoms Study (EMOSS). Fasting morning blood plasma samples were collected after the overnight sleep study. A multiple linear regression model was utilized to examine the association between metabolites of interest and sleep latency, controlling for baseline covariates of age, sex, body mass index (BMI), race, smoking status, and apnea hypopnea index (AHI).

RESULTS

Among the targeted metabolites, aminoacetone showed a significant association with sleep latency (adjusted mean (SE) = -0.39 (0.11); p = 0.00072). Participants with sleep onset latency >60 min had lower levels of aminoacetone than patients with sleep onset latency <15 min.

CONCLUSION

This is the first study to evaluate the relationship between aminoacetone and sleep latency in participants with newly diagnosed OSA. Our findings suggests that aminoacetone is associated with sleep latency in participants with OSA.

Can Endogenous or Exogenous Ketosis Tackle the Constraints of Ultraendurance Exercise?

A high-fat, low-carbohydrate, ketogenic diet has appealed to athletes for a long time due to its purported ability to improve exercise performance and postexercise recovery. The availability of ketone supplements has further sparked such interest. The review, therefore, focuses on the potential beneficial impact of exogenous and endogenous ketosis in the context of ultraendurance exercise.

Identifying iNOS and glycogen as biomarkers for degenerated cerebellar purkinje cells in autism spectrum disorder: Protective effects of erythropoietin and zinc sulfate

Autism spectrum disorder (ASD) is a collective neurodevelopmental disorder affecting young children and accounting for 1% of the world's population. The cerebellum is the major part of the human brain affected by ASD and is associated with a substantial reduction in the number of Purkinje cells. An association between ASD and the expression of the nitrosative stress biomarker inducible nitric oxide synthase (iNOS), as well as glycogen deposition in damaged Purkinje cells, has not been previously reported in the medical literature. To explore this correlation, young rats were injected with propionic acid (PPA) (500 mg/kg) for 5 days (model group), while the protection groups were treated with either erythropoietin (EPO, 5,000 U/kg) or 2 mg/kg zinc sulfate immediately after the PPA injections. ASD-like features were developed in the model group, as evidenced by cerebellum damage (degeneration of Purkinje cells) and cerebellar dysfunction (behavioral impairment). This study documented the exclusive expression of iNOS in the degenerated Purkinje cells, along with glycogen deposition in these cells. Additionally, PPA significantly (p < 0.001) modulated cerebellar tissue levels of mammalian target of rapamycin (mTOR), gamma-aminobutyric acid (GABA), GABAA receptor, serotonin, the marker of neuronal loss (calbindin D28K), and social interaction deficit. Some of these parameters were differentially protected by EPO and zinc sulfate, with the former providing greater protection than zinc sulfate. Furthermore, a significant correlation between the iNOS score and these parameters associated with ASD was observed. These findings demonstrate the colocalization of iNOS and glycogen in the damaged Purkinje cells induced by ASD, along with the modulation of ASD parameters, which were protected by EPO and zinc sulfate treatments. Thus, these potential novel biomarkers may offer possible therapeutic targets for the treatment of ASD.

Assessment of sedative activity of Chrysin: Behavioral approach with pharmacokinetics, toxicological profile and molecular docking

The purpose of this study was to investigate the sedative effects of Chrysin (CHR) along with modulatory effects on diazepam (DZP) and flumazenil (FLU) in an animal sleep model produced by thiopental sodium (TS). Additionally, we explored the pharmacokinetics and potential GABAA receptor interactions of CHR through computational studies. Swiss albino mice were treated with intraperitoneal administration of CHR (5 and 10 mg/kg), DZP (2 mg/kg), and FLU (0.1 mg/kg) either alone or in combination. Sleeping onset and duration were measured following TS administration. Molecular docking was performed to investigate CHR's binding affinity with GABAA (PDB: 6X3X) receptors. Results found that CHR significantly (p < 0.05) reduced sleep latency and increased sleep duration in a dose-dependent manner compared to the control group. The highest dose (CHR-10) exhibited the most potent significant sedative effect with onset (11.57 ± 1.74 min) and duration (172.86 ± 7.37 min). Combination therapy of CHR-10 with DZP resulted in synergistic effects, further enhancing sleep duration. In molecular docking, CHR demonstrated a higher binding affinity (-8.9 kcal/mol) for GABAA receptors compared to DZP (-8.7 kcal/mol) and FLU (-6.6 kcal/mol). CHR also showed favorable pharmacokinetic properties with high intestinal absorption and low toxicity. CHR exhibits promising sedative activity, with the potential to enhance the effects of traditional sedatives like DZP. However, further research, including clinical trials and detailed mechanistic studies, is warranted to explore its full therapeutic potential.

Cortical excitability on sleep deprivation measured by transcranial magnetic stimulation: A systematic review and meta-analysis

Sleep deprivation is a common public problem, and researchers speculated its neurophysiological mechanisms related to cortical excitatory and inhibitory activity. Recently, transcranial magnetic stimulation combined with electromyography (TMS-EMG) and electroencephalography (TMS-EEG) have been used to assess cortical excitability in sleep-deprived individuals, but the results were inconsistent. Therefore, we conducted a meta-analysis to summarize relevant TMS-evoked indices of excitability and inhibition for exploring the cortical effects of sleep deprivation. In TMS-EMG studies, short-interval cortical inhibition (SICI) significantly decreased in sleep-deprived subjects; while the intracortical facilitation (ICF), resting motor threshold (RMT), and cortical silent period (CSP) were not significant compared to healthy controls. In TMS-EEG studies, the amplitude and slope of TMS-evoked potential (TEP) increased in sleep-deprived subjects. This study indicated that cortical inhibition decreased following sleep deprivation based on the TMS-EMG results and cortical excitability enhanced in the TMS-EEG results, supporting the disturbance of cortical excitability in sleep-deprived individuals.

Enhancing sleep quality in synucleinopathies through physical exercise

During sleep, several crucial processes for brain homeostasis occur, including the rearrangement of synaptic connections, which is essential for memory formation and updating. Sleep also facilitates the removal of neurotoxic waste products, the accumulation of which plays a key role in neurodegeneration. Various neural components and environmental factors regulate and influence the physiological transition between wakefulness and sleep. Disruptions in this complex system form the basis of sleep disorders, as commonly observed in synucleinopathies. Synucleinopathies are neurodegenerative disorders characterized by abnormal build-up of α-synuclein protein aggregates in the brain. This accumulation in different brain regions leads to a spectrum of clinical manifestations, including hypokinesia, cognitive impairment, psychiatric symptoms, and neurovegetative disturbances. Sleep disorders are highly prevalent in individuals with synucleinopathies, and they not only affect the overall well-being of patients but also directly contribute to disease severity and progression. Therefore, it is crucial to develop effective therapeutic strategies to improve sleep quality in these patients. Adequate sleep is vital for brain health, and the role of synucleinopathies in disrupting sleep patterns must be taken into account. In this context, it is essential to explore the role of physical exercise as a potential non-pharmacological intervention to manage sleep disorders in individuals with synucleinopathies. The current evidence on the efficacy of exercise programs to enhance sleep quality in this patient population is discussed.

Gene expression is associated with brain function of insomnia disorder, rather than brain structure

Previous research has found brain structural and functional abnormalities in patients with insomnia disorder (ID). However, the relationship between brain abnormalities in ID and brain gene expression is unclear. This study explored the relationship between gene expression and brain structural or functional abnormalities in ID, and we validated the reliability of the results with two independent datasets (discover dataset: healthy control (HC) = 129, ID = 264; validation dataset: HC = 160, ID = 115). Brain imaging results show that ID has abnormal resting-state spontaneous activity, regional homogeneity, and widespread gray matter volume reduction compared to HC. The association analysis results with gene expression further revealed that brain function abnormalities in ID were significantly associated with gene expression, but structural abnormalities were not. This study establishes a link between transcriptional changes and brain functional abnormalities in ID, revealing a genetic basis that may involve several biological pathways. Specifically, these pathways include hormonal regulation of the hypothalamic-pituitary-adrenal (HPA) axis, which plays a crucial role in stress response and sleep regulation; ion transport across membranes, vital for neuronal communication; and inhibitory neuronal regulation, essential for maintaining normal brain function. Furthermore, the ID-related genes are enriched for brain tissue and cortical cells, emphasizing their relevance in understanding the biological underpinnings of ID.

GABALAGEN Alleviates Stress-Induced Sleep Disorders in Rats

(1) Background: Gamma-aminobutyric acid (GABA) is an amino acid and the primary inhibitory neurotransmitter in the brain. GABA has been shown to reduce stress and promote sleep. GABALAGEN (GBL) is the product of fermented fish collagen by Lactobacillus brevis BJ20 and Lactobacillus plantarum BJ21, naturally enriched with GABA through the fermentation process and characterized by low molecular weight. (2) Methods: The present study evaluated the GABAA affinity of GBL through receptor binding assay. The sedative effects of GBL were investigated through electroencephalography (EEG) analysis in an animal model of electro foot shock (EFS) stress-induced sleep disorder, and then we examined the expression of orexin and the GABAA receptor in the brain region using immunohistochemistry and an enzyme-linked immunosorbent assay (ELISA). (3) Results: We found that on the binding assay, GBL displayed high affinity to the GABAA receptor. Also, after treatment with GBL, the percentage of the total time in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep was significantly and dose-dependently increased in EFS-induced rats. Consistent with behavioral results, the GBL-treated groups showed that the expression of GABAA receptor immune-positive cells in the VLPO was markedly and dose-dependently increased. Also, the GBL-treated groups showed that the expression of the orexin-A level in LH was significantly decreased. (4) Conclusions: GBL showed efficacy and potential to be used as an anti-stress therapy to treat sleep deprivation through the stimulation of GABAA receptors and the consequent inhibition of orexin activity.

Microbiome-Based Therapeutics for Insomnia

Insomnia poses considerable risks to both physical and mental health, leading to cognitive impairment, weakened immune function, metabolic dysfunction, cardiovascular issues, and reduced quality of life. Given the significant global increase in insomnia and the growing scientific evidence connecting gut microbiota to this disorder, targeting gut microbiota as an intervention for insomnia has gained popularity. In this review, we summarize current microbiome-based therapeutics for insomnia, including dietary modifications; probiotic, prebiotic, postbiotic, and synbiotic interventions; and fecal microbiota transplantation. Moreover, we assess the capabilities and weaknesses of these technologies to offer valuable insights for future studies.

The Effect of Water-Soluble Alpinia Galanga Extract on Sleep and the Activation of the GABAAergic/Serotonergic Pathway in Mice

Background/Objectives: With increasing interest in plant-based compounds that can enhance sleep quality without the side effects of caffeine, Alpinia galanga (AG) has emerged as a promising herbal supplement for improving mental alertness. This study assessed the impact of water-soluble AG extract on sleep quality; the activity of GABAergic, glutamatergic, and serotonergic receptors; and concentrations of dopamine and serotonin in the brains of mice. Methods: The study employed two experimental models using BALB/c mice to examine the impact of pentobarbital-induced sleep and caffeine-induced insomnia. In the first model, a set of 20 mice was assigned to four groups to assess the effects of pentobarbital (42 mg/kg) or pentobarbital with AG extract on sleep induction, with observations made 45 min post-administration. In the second model, 20 mice were divided into four groups to evaluate the impact of caffeine (25 mg/kg) alone or caffeine with varying doses of AG extract (61.25 or 205.50 mg/kg administered orally) on brain activity along with additional analyses on receptor proteins and neurotransmitters. Results: A higher dose of AG extract (205.50 mg/kg) significantly increased total deep sleep duration compared to the caffeine group (p < 0.0001). Furthermore, this dose extended sleep latency and suppressed GABAergic and glutamatergic receptor activity compared to the lower AG dose (p < 0.05). Additionally, the 205.50 mg/kg dose elevated serotonin and dopamine levels compared to caffeine (p < 0.0001), suggesting improved sleep quality alongside enhanced wakefulness. Conclusions: Our data indicate that a higher dose of AG extract improved sleep latency and duration by regulating GABAergic and glutamatergic receptors through the GABAergic/serotonergic pathway in mice.

Sleep-improving effect and the potential mechanism of Morus alba L. on mice

As insufficient sleep has become a widespread concern in modern society, potential sleep-improving effect of mulberry (Morus alba L.) leaf ethanol extract (MLE) and the related mechanism were investigated in the present study. According to the results, MLE could significantly shorten sleep latency by 33 %, extend sleep duration by 56 % and increase sleep ratio of mice through increasing 5-HT and GABA release in serum, hypothalamus and hippocampus. Metabonomic analysis showed that phenylalanine metabolism, arginine and proline metabolism might be the potential pathways of MLE to improve sleep. Network pharmacological and LC-MS analysis suggested that the key sleep-improving active ingredients in MLE might be luteolin, kaempferol, naringenin, morin, stigmasterol and β-sitosterol. Further molecular docking and qRT-PCR results demonstrated that the key targets for MLE to improve sleep might be MAOA, GABRA1 and GABRA2. In conclusion, MLE showed outstanding sleep-improving effect and great potential for the application as novel sleep-improving functional food.

Progress in GABAA receptor agonists for insomnia disorder

Insomnia is the most common sleep disorder in which an individual has trouble falling or staying asleep. Chronic sleep loss interferes with daily functioning and adversely affects health. The main clinical drugs for insomnia are the positive allosteric modulator of the GABA (gamma-aminobutyric acid) A receptors (GABAARs) at the benzodiazepine site with selectivity of the GABA-α1 receptor. They are divided into benzodiazepine drugs and non-benzodiazepine drugs. Most recently, the first partial positive allosteric modulator of GABAAR Dimdazenil was approved by National Medical Products Administration (NMPA) and launched in China. This review summarized the mechanism of actions of current clinical drugs for insomnia, and the clinical applications of these drugs, which may help to understand their involvement in insomnia, and to search for more selective and potent ligands to be used in the treatment of insomnia.

Phytol exerts sedative-like effects and modulates the diazepam and flumazenil's action, possibly through the GABAA receptor interaction pathway

This study aimed at the evaluation of the sedative effect of phytol (PHY) with possible molecular mechanisms through in vivo and in silico studies. For this, adult male mice were randomly divided into six individual groups, namely control (vehicle), two standards (DZP: diazepam at 2 m/kg, FLU: flumazenil at 0.1 mg/kg), three test groups (PHY at 25, 50, and 75 mg/kg), and three combined groups with the DZP-2 and/or FLU-0.1 with PHY-75 mg/kg. After thirty minutes, each animal was treated with thiopental sodium (TS) at 40 mg/kg to produce sedation and observed for latency and duration of sleep up to 4 h. In silico studies were performed with the 6X3X protein of the GABAA receptor α1 and β2 subunits. The results demonstrate that PHY dose-dependently enhanced sleep duration in animals. However, it produced an insignificant sleep duration compared to the control and standard groups. It also significantly (p < 0.05) decreased the latency and increased the duration of sleep with DZP-2, while reducing these parameters with FLU-0.1. In in silico studies, DZP and FLU exhibited binding affinities with 6X3X by -6.8 and -6.9 kcal/mol, respectively, while PHY exhibited -6.9 kcal/mol. Taken together, PHY may exert a sedative-like effect in TS-induced sleeping mice and modulate the effects of DZP and FLU, possibly through interacting with the 6X3X protein of the GABAA receptor. PHY may be one of the good candidates for the management of sleep disturbances, such as insomnia.

Improvement of sleep duration and quality through GABAA receptor by whey protein hydrolysate containing DIQK as the main active compound

This study characterized the sleep activity, sleep mechanism, and active peptides of whey protein hydrolysates selected through behavioral analysis of fruit flies (Drosophila melanogaster). Sleep-inducing whey protein (WP) hydrolysate was selected through fruit fly behavior analysis, and sleep activity was measured using a pentobarbital model and electroencephalographic analysis. The mechanism of action was confirmed using a γ-aminobutyric acid (GABA) receptor antagonist, and the active peptide was identified using liquid chromatography-mass spectrometry. Whey protein hydrolysate, prepared using Alcalase and Prozyme (WP-AP), increased sleep time in a dose-dependent manner. The WP-AP significantly increased not only sleep time but also slow-wave sleep and showed an insomnia-alleviating effect in a caffeine-induced insomnia mouse model. In addition, the gene and protein expression levels of GABA subtype A receptors increased in the brains of mice orally administered with WP-AP. Through peptide analysis, the mixture of DIQK, VPPF peptide, and GABA contained in WP-AP was estimated to exhibit sleep activity, and due to its high content, DIQK was speculated to be the main sleep-inducing ingredient. These results indicate that WP-AP has the potential to be used as a new ingredient to improve sleep quality.

Efficacy and safety of auricular acupressure on reduction of estazolam in patients with insomnia: a study protocol for a three-arm, blinded randomized controlled trial

BACKGROUND

Drug-dependent insomnia refers to insomnia patients taking sedatives and sleeping pills regularly for a long period. Auricular acupressure (AA) has attracted growing attention as a complementary treatment for insomnia. Nevertheless, there is a lack of rigorous studies evaluating AA specifically for estazolam-dependent insomnia. Our proposed trial aims to assess the therapeutic effect of AA on estazolam-dependent insomnia.

METHODS

This study is a randomized, single-blinded, three-arm controlled trial. No less than 108 participants will be randomized into one of three groups: AA group, sham auricular acupressure (SAA) group, and conventional dosage reduction group. All treatments will be administered for 4 weeks, with a follow-up period of 1 month. The primary clinical outcomes will be estazolam dosing and reduction rates, serum gamma-aminobutyric acid (GABA) and cortisol (CORT) levels. Secondary outcomes will concern the Pittsburgh sleep quality index (PSQI) and Benzodiazepine Withdrawal Symptom Questionnaire (BWSQ). Both intention-to-treat and per-protocol analyses will be performed, with the significance level determined as 5%.

DISCUSSION

The study results will provide evidence on the efficacy and safety of AA in managing estazolam-dependent insomnia by analyzing its immediate effect, time-effect relationship, and reduction of estazolam use.

TRIAL REGISTRATION

Clinicaltrials.gov (identification number: NCT06258226; Registered 5 February 2024, https://clinicaltrials.gov/ct2/show/NCT06258226 ).

Consumption of poly-γ-glutamate-vitamin B6 supplement and urinary microbiota profiles in Korean healthy adults: a randomized, double-blinded, placebo-controlled intervention study

BACKGROUND/OBJECTIVES

Poly-γ-glutamic acid (γ-PGA), a natural polymer found in fermented soybean products, has been reported to play a prebiotic role in the gut. This intervention study investigated the effects of γ-PGA-containing supplement consumption on urinary microbiota in healthy adults because of limited data on such investigation.

SUBJECTS/METHODS

A 4-week parallel trial including 39 male and female Korean adults, who were free of chronic diseases and infection, was designed as a randomized, double-blinded, placebo-controlled study. A total of 30 participants completed the study wherein the intervention group (n = 17) received a mixture supplement containing 600 mg/day of γ-PGA and 100 mg/day of vitamin B6, while the control group (n = 13) received a placebo. Paired datasets (baseline and endpoint data) of microbiota profiles, which were constructed via urinary assays of microbe-derived extracellular vesicles, were analyzed and compared between the two groups.

RESULTS

Only the intervention group yielded significant results for the Bray-Curtis and Jaccard dissimilarity indices between baseline and endpoint data (P < 0.05). In the phylum-level analysis of microbial composition, the Firmicutes to Bacteroidetes ratio (FB ratio) tended to decrease from baseline in the intervention group; however, it increased in the control group. Differences between the baseline and endpoint FB ratios were significant between the two groups (P < 0.05).

CONCLUSION

This study's findings suggest that γ-PGA-vitamin B6 supplementation potentially alters the microbial community composition of a host. Further investigation into the biological consequences of commensal microbiota alteration by γ-PGA-containing supplement consumption is warranted.

Antioxidant Carbon Dots Nanozymes Alleviate Stress-induced Depression by Modulating Gut Microbiota

Depression is a debilitating mental illness that severely threatens millions of individuals and public health. Because of the multifactorial etiologies, there is currently no cure for depression; thus, it is urgently imperative to find alternative antidepressants and strategies. Growing evidence underscores the prominent role of oxidative stress as key pathological hallmarks of depression, making oxidative stress a potential therapeutic target. In this study, we report a N-doped carbon dot nanozyme (CDzyme) with excellent antioxidant capacity for treating depression by remodeling redox homeostasis and gut microbiota. The CDzymes prepared via microwave-assisted fast polymerization of histidine and glucose exhibit superior biocompatibility. Benefiting from the unique structure, CDzymes can provide abundant electrons, hydrogen atoms, and protons for reducing reactions, as well as catalytic sites to mimic redox enzymes. These mechanisms collaborating endow CDzymes with broad-spectrum antioxidant capacity to scavenge reactive oxygen and nitrogen species (•OH, O2-•, H2O2, ONOO-), and oxygen/nitrogen centered free radicals. A depression animal model was established by chronic unpredictable mild stress (CUMS) to evaluate the therapeutic efficacy of CDzymes from the behavioral, physiological, and biochemical index and intestinal flora assessments. CDzymes can remarkably improve depression-like behaviors and key neurotransmitters produced in hippocampus tissues and restore the gut microbiota compositions and the amino acid metabolic functions, proving the potential in treating depression through the intestinal-brain axis system. This study will facilitate the development of intestinal flora dysbiosis nanomedicines and treatment strategies for depression and other oxidative stress related multifactorial diseases.

Steroid Hormone Biosynthesis and Dietary Related Metabolites Associated with Excessive Daytime Sleepiness

Background

Excessive daytime sleepiness (EDS) is a complex sleep problem that affects approximately 33% of the United States population. Although EDS usually occurs in conjunction with insufficient sleep, and other sleep and circadian disorders, recent studies have shown unique genetic markers and metabolic pathways underlying EDS. Here, we aimed to further elucidate the biological profile of EDS using large scale single- and pathway-level metabolomics analyses.

Methods

Metabolomics data were available for 877 metabolites in 6,071 individuals from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) and EDS was assessed using the Epworth Sleepiness Scale (ESS) questionnaire. We performed linear regression for each metabolite on continuous ESS, adjusting for demographic, lifestyle, and physiological confounders, and in sex specific groups. Subsequently, gaussian graphical modelling was performed coupled with pathway and enrichment analyses to generate a holistic interactive network of the metabolomic profile of EDS associations.

Findings

We identified seven metabolites belonging to steroids, sphingomyelin, and long chain fatty acids sub-pathways in the primary model associated with EDS, and an additional three metabolites in the male-specific analysis. The identified metabolites particularly played a role in steroid hormone biosynthesis.

Interpretation

Our findings indicate that an EDS metabolomic profile is characterized by endogenous and dietary metabolites within the steroid hormone biosynthesis pathway, with some pathways that differ by sex. Our findings identify potential pathways to target for addressing the causes or consequences of EDS and related sleep disorders.

Funding

Details regarding funding supporting this work and all studies involved are provided in the acknowledgments section.

Sedative Effects of Daidzin, Possibly Through the GABAA Receptor Interaction Pathway: In Vivo Approach with Molecular Dynamic Simulations

The soy isoflavone daidzin (DZN) has been considered a hopeful bioactive compound having diverse biological activities, including anxiolytic, memory-enhancing, and antiepileptic effects, in experimental animals. However, its sedative and hypnotic effects are yet to be discovered. This study aimed to evaluate its sedative/hypnotic effect on Swiss mice. Additionally, in silico studies were also performed to see the possible molecular mechanisms behind the tested neurological effect. For this, male Swiss albino mice were treated with DZN (5, 10, or 20 mg/kg) intraperitoneally (i.p.) with or without the standard GABAergic medication diazepam (DZP) and/or flumazenil (FLU) and checked for the onset and duration of sleeping time using thiopental sodium-induced as well as DZP-induced sleeping tests. A molecular docking study was also performed to check its interaction capacity with the α1 and β2 subunits of the GABAA receptor. Findings suggest that DZN dose-dependently and significantly reduced the latency while increasing the duration of sleep in animals. In combination therapy, DZN shows synergistic effects with the DZP-2 and DZP-2 + FLU-0.01 groups, resulting in significantly (p < 0.05) reduced latency and increased sleep duration. Further, molecular docking studies demonstrate that DZN has a strong binding affinity of - 7.2 kcal/mol, which is closer to the standard ligand DZP (- 8.3 kcal/mol) against the GABAA (6X3X) receptor. Molecular dynamic simulations indicated stability and similar binding locations for DZP and DZN with 6X3X. In conclusion, DZN shows sedative effects on Swiss mice, possibly through the GABAA receptor interaction pathway.

Fly into tranquility: GABA's role in Drosophila sleep

Sleep is conserved across the animal kingdom, and Drosophila melanogaster is a prime model to understand its intricate circadian and homeostatic control. GABA (gamma-aminobutyric acid), the brain's main inhibitory neurotransmitter, plays a central role in sleep. This review delves into GABA's complex mechanisms of actions within Drosophila's sleep-regulating neural networks. We discuss how GABA promotes sleep, both by inhibiting circadian arousal neurons and by being a key neurotransmitter in sleep homeostatic circuits. GABA's impact on sleep is modulated by glia through astrocytic GABA recapture and metabolism. Interestingly, GABA can be coexpressed with other neurotransmitters in sleep-regulating neurons, which likely contributes to context-based sleep plasticity.

Periostracum Cicadae Extract and N-Acetyldopamine Regulate the Sleep-Related Neurotransmitters in PCPA-Induced Insomnia Rats

Insomnia is the second most prevalent mental illness worldwide. Periostracum cicadae (PC), as an animal traditional Chinese medicine with rich pharmacological effects, has been documented as a treatment for children's night cries, and later extended to treat insomnia. This study aimed to investigate the effects of PC extract and N-acetyldopamine compounds in ameliorating insomnia. The UPLC-ESI-QTOF-MS analysis determined that PC extract mainly contained N-acetyldopamine components. Previously, we also isolated some acetyldopamine polymers from PC extract, among which acetyldopamine dimer A (NADA) was present in high content. Molecular docking and molecular dynamic simulations demonstrated that NADA could form stable complexes with 5-HT1A, BDNF, and D2R proteins, respectively. The effects of PC extract and NADA on insomnia were evaluated in the PCPA-induced insomnia model. The results indicated that PC extract and NADA could effectively ameliorate hypothalamic pathology of insomnia rats, increase the levels of 5-HT, GABA, and BDNF, and decrease the levels of DA, DOPAC, and HVA. Meanwhile, the PC extract and NADA also could significantly affect the expression of 5-HT1A, BDNF, and DARPP-32 proteins. This study proved that PC extract and acetyldopamine dimer A could effectively improve PCPA-induced insomnia in rats. It is speculated that the main pharmacological substances of PC were acetyldopamine components.

Combined effects of pharmacological interventions and intermittent theta-burst stimulation on motor sequence learning

Drugs that modulate N-methyl-D-aspartate (NMDA) or γ-Aminobutyric acid type A (GABA A ) receptors can shed light on their role in synaptic plasticity mechanisms underlying the effects of non-invasive brain stimulation. However, research on the combined effects of these drugs and exogenous stimulation on motor learning is limited. This study aimed to investigate the effects of pharmacological interventions combined with intermittent theta-burst stimulation (iTBS) on human motor learning. Nine right-handed healthy subjects (mean age ± SD: 31.56 ± 12.96 years; 6 females) participated in this double-blind crossover study. All participants were assigned to four drug conditions in a randomized order: (1) D-cycloserine (partial NMDA receptor agonist), (2) D-cycloserine + dextromethorphan (NMDA receptor agonist + antagonist), (3) lorazepam (GABA A receptor agonist), and (4) placebo (identical microcrystalline cellulose capsule). After drug intake, participants practiced the 12-item keyboard sequential task as a baseline measure. Two hours after drug intake, iTBS was administered at the primary motor cortex. Following iTBS, the retention test was performed in the same manner as the baseline measure. Our findings revealed that lorazepam combined with iTBS impaired motor learning during the retention test. Future studies are still needed for a better understanding of the mechanisms through which TMS may influence human motor learning.

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.

Lactuca sativa L. Extract Enhances Sleep Duration Through Upregulation of Adenosine A1 Receptor and GABAA Receptors Subunits in Pentobarbital-Injected Mice

We investigated the effects of Lactuca sativa L. extracts (Lactuc) on pentobarbital-induced sleep in mice to elucidate the mechanisms underlying its impact on sleep quality. Mice were randomly assigned to five groups: control, positive control (diazepam 2 mg/kg b.w.), and three groups orally administered with Lactuc (50, 100, and 200 mg/kg b.w.). After 2 weeks of oral administration and intraperitoneal injections, the mice were killed. We found that the Lactuc-administered groups had significantly reduced sleep latency and increased sleep duration compared with the control group. Furthermore, the oral administration of Lactuc induced a significant increase in mRNA expression and protein expression of adenosine A1 receptor in the brains compared with the expressions in the control group. In addition, the Lactuc-administered groups exhibited significantly higher levels of mRNA expressions of GABAA receptors subunits α2, β2, γ1, and, γ2 in the brain tissue. Therefore, we suggest that Lactuc could be used to develop natural products that effectively improve sleep quality and duration.

The effect of modified Qiyuan paste on mice with low immunity and sleep deprivation by regulating GABA nerve and immune system

BACKGROUND

Low immunity and sleep disorders are prevalent suboptimal health conditions in contemporary populations, which render them susceptible to the infiltration of pathogenic factors. LJC, which has a long history in traditional Chinese medicine for nourishing the Yin and blood and calming the mind, is obtained by modifying Qiyuan paste. Dendrobium officinale Kimura et Migo has been shown to improve the immune function in sleep-deprived mice. In this study, based on the traditional Chinese medicine theory, LJC was prepared by adding D. officinale Kimura et Migo to Qiyuan paste decoction.

METHODS

Indicators of Yin deficiency syndrome, such as back temperature and grip strength, were measured in each group of mice; furthermore, behavioral tests and pentobarbital sodium-induced sleep tests were performed. An automatic biochemical analyzer, enzyme-linked immunosorbent assay kit, and other methods were used to determine routine blood parameters, serum immunoglobulin (IgG, IgA, and IgM), cont (C3, C4), acid phosphatase (ACP) and lactate dehydrogenase (LDH) levels in the spleen, serum hemolysin, and delayed-type hypersensitivity (DTH) levels. In addition, serum levels of γ-aminobutyric acid (GABA) and glutamate (Glu) were detected using high-performance liquid chromatography (HPLC). Hematoxylin-eosin staining and Nissl staining were used to assess the histological alterations in the hypothalamus tissue. Western blot and immunohistochemistry were used to detect the expressions of the GABA pathway proteins GABRA1, GAD, GAT1, and GABAT1 and those of CD4+ and CD8+ proteins in the thymus and spleen tissues.

RESULTS

The findings indicated that LJC prolonged the sleep duration, improved the pathological changes in the hippocampus, effectively upregulated the GABA content in the serum of mice, downregulated the Glu content and Glu/GABA ratio, enhanced the expressions of GABRA1, GAT1, and GAD, and decreased the expression of GABAT1 to assuage sleep disorders. Importantly, LJC alleviated the damage to the thymus and spleen tissues in the model mice and enhanced the activities of ACP and LDH in the spleen of the immunocompromised mice. Moreover, serum hemolysin levels and serum IgG, IgA, and IgM levels increased after LJC administration, which manifested as increased CD4+ content, decreased CD8+ content, and enhanced DTH response. In addition, LJC significantly increased the levels of complement C3 and C4, increased the number of white blood cells and lymphocytes, and decreased the percentage of neutrophils in the blood.

CONCLUSIONS

LJC can lead to improvements in immunocompromised mice models with insufficient sleep. The underlying mechanism may involve regulation of the GABA/Glu content and the expression levels of GABA metabolism pathway-related proteins in the brain of mice, enhancing their specific and nonspecific immune functions.

Reversal of Obesity by Enhancing Slow-wave Sleep via a Prokineticin Receptor Neural Circuit

Obese subjects often exhibit hypersomnia accompanied by severe sleep fragmentation, while emerging evidence suggests that poor sleep quality promotes overeating and exacerbates diet-induced obesity (DIO). However, the neural circuit and signaling mechanism underlying the reciprocal control of appetite and sleep is yet not elucidated. Here, we report a neural circuit where prokineticin receptor 2 (PROKR2)-expressing neurons within the parabrachial nucleus (PBN) of the brainstem received direct projections from neuropeptide Y receptor Y2 (NPY2R)-expressing neurons within the lateral preoptic area (LPO) of the hypothalamus. The RNA-Seq results revealed Prokr2 in the PBN is the most regulated GPCR signaling gene that is responsible for comorbidity of obesity and sleep dysfunction. Furthermore, those NPY2R LPO neurons are minimally active during NREM sleep and maximally active during wakefulness and REM sleep. Activation of the NPY2R LPO →PBN circuit or the postsynaptic PROKR2 PBN neurons suppressed feeding of a high-fat diet and abrogated morbid sleep patterns in DIO mice. Further studies showed that genetic ablation of the PROKR2 signaling within PROKR2 PBN neurons alleviated the hyperphagia and weight gain, and restored sleep dysfunction in DIO mice. We further discovered pterostilbene, a plant-derived stilbenoid, is a powerful anti-obesity and sleep-improving agent, robustly suppressed hyperphagia and promoted reconstruction of a healthier sleep architecture, thereby leading to significant weight loss. Collectively, our results unveil a neural mechanism for the reciprocal control of appetite and sleep, through which pterostilbene, along with a class of similarly structured compounds, may be developed as effective therapeutics for tackling obesity and sleep disorders.

Adaptive changes in BMAL2 with increased locomotion associated with the evolution of unihemispheric slow-wave sleep in mammals

Marine mammals, especially cetaceans, have evolved a very special form of sleep characterized by unihemispheric slow-wave sleep (USWS) and a negligible amount or complete absence of rapid-eye-movement sleep; however, the underlying genetic mechanisms remain unclear. Here, we detected unique, significant selection signatures in basic helix-loop-helix ARNT like 2 (BMAL2; also called ARNTL2), a key circadian regulator, in marine mammal lineages, and identified two nonsynonymous amino acid substitutions (K204E and K346Q) in the important PER-ARNT-SIM domain of cetacean BMAL2 via sequence comparison with other mammals. In vitro assays revealed that these cetacean-specific mutations specifically enhanced the response to E-box-like enhancer and consequently promoted the transcriptional activation of PER2, which is closely linked to sleep regulation. The increased PER2 expression, which was further confirmed both in vitro and in vivo, is beneficial for allowing cetaceans to maintain continuous movement and alertness during sleep. Concordantly, the locomotor activities of zebrafish overexpressing the cetacean-specific mutant bmal2 were significantly higher than the zebrafish overexpressing the wild-type gene. Subsequently, transcriptome analyses revealed that cetacean-specific mutations caused the upregulation of arousal-related genes and the downregulation of several sleep-promoting genes, which is consistent with the need to maintain hemispheric arousal during USWS. Our findings suggest a potential close relationship between adaptive changes in BMAL2 and the remarkable adaptation of USWS and may provide novel insights into the genetic basis of the evolution of animal sleep.

Impact of evolution on lifestyle in microbiome

This chapter analyses the interaction between microbiota and humans from an evolutionary point of view. Long-term interactions between gut microbiota and host have been generated as a result of dietary choices through coevolutionary processes, where mutuality of advantage is essential. Likewise, the characteristics of the intestinal environment have made it possible to describe different intrahost evolutionary mechanisms affecting microbiota. For its part, the intestinal microbiota has been of great importance in the evolution of mammals, allowing the diversification of dietary niches, phenotypic plasticity and the selection of host phenotypes. Although the origin of the human intestinal microbial community is still not known with certainty, mother-offspring transmission plays a key role, and it seems that transmissibility between individuals in adulthood also has important implications. Finally, it should be noted that certain aspects inherent to modern lifestyle, including refined diets, antibiotic intake, exposure to air pollutants, microplastics, and stress, could negatively affect the diversity and composition of our gut microbiota. This chapter aims to combine current knowledge to provide a comprehensive view of the interaction between microbiota and humans throughout evolution.

Terpenoids derived from Semen Ziziphi Spinosae oil enhance sleep by modulating neurotransmitter signaling in mice

Semen Ziziphi Spinosae oil (SZSO) is a natural vegetable oil extracted from Semen Ziziphi Spinosae, a traditional Chinese medicine renowned for its sleep-promoting properties, while the mechanisms are still unclear. Our findings revealed that the terpenoids present in SZSO (T-SZSO) were identified as the active components responsible for promoting sleep. Network pharmacological analysis suggested that T-SZSO targeted different sleep-aid pathways to varying degrees and exhibited potential for preventing central nervous system diseases. Notably, lupeol and betulinicaldehyde exhibited more pronounced effects. Additionally, T-SZSO significantly elevated serotonin levels, enhanced gamma-aminobutyric acid (GABA) synthesis, promoted GABA A receptor expression, and decreased glutamate and norepinephrine expression levels. Moreover, T-SZSO was found to downregulate IL-1β expression while upregulating superoxide dismutase and inducible nitric oxide synthase levels. In conclusion, this study presents the first investigation into the pharmacological basis of SZSO in promoting sleep and highlights the potential of nature food in improving suboptimal health conditions.

Pharmacokinetics, tissue distribution, and plasma protein binding ratio of bicuculline following intragastric and intravenous administration in rats using ultra-high-performance liquid chromatography-tandem mass spectrometry

Bicuculline is a natural isoquinoline alkaloid that works as a gamma-aminobutyric acid receptor antagonist. It is widely found in Papaveraceae plants used in traditional Chinese medicines. Bicuculline not only has been shown to have favorable analgesic, memory-improving, and anxiolytic effects but may also cause adverse effects such as convulsions and epilepsy. A simple, rapid, and sensitive method was developed and validated for the determination of bicuculline in the plasma and tissue samples in rats by ultra-high-performance liquid chromatography-tandem mass spectrometry (MS/MS). The chromatographic separation was performed on a Thermo Scientific C18 column. The MS/MS system was operated in the positive multiple reaction monitoring mode, and the precursor-product ion transitions were optimized as m/z 368.0 → 307.1 for bicuculline and as 354.1 → 188.1 for protopine (internal standard). The linearity, accuracy, precision, recovery, and matrix effect were within acceptable limits. The experimental data showed that bicuculline was rapidly absorbed and eliminated in rats, with a moderate plasma protein binding ratio and low bioavailability. The main tissues of distribution were the kidney, liver, and brain; bicuculline could exert its pharmacological effects across the blood-brain barrier. This study has positive implications for the clinical use of herbal medicines containing bicuculline and for further development.

Advances in the Immunology of the Host-Parasite Interactions in African Trypanosomosis, including Single-Cell Transcriptomics

Trypanosomes are single-celled extracellular parasites that infect mammals, including humans and livestock, causing global public health concerns and economic losses. These parasites cycle between insect vectors, such as tsetse flies and vertebrate hosts, undergoing morphological, cellular, and biochemical changes. They have remarkable immune evasion mechanisms to escape the host's innate and adaptive immune responses, such as surface coat antigenic variation and the induction of the loss of specificity and memory of antibody responses, enabling the prolongation of infection. Since trypanosomes circulate through the host body in blood and lymph fluid and invade various organs, understanding the interaction between trypanosomes and tissue niches is essential. Here, we present an up-to-date overview of host-parasite interactions and survival strategies for trypanosomes by introducing and discussing the latest studies investigating the transcriptomics of parasites according to life cycle stages, as well as host cells in various tissues and organs, using single-cell and spatial sequencing applications. In recent years, this information has improved our understanding of trypanosomosis by deciphering the diverse populations of parasites in the developmental process, as well as the highly heterogeneous immune and tissue-resident cells involved in anti-trypanosome responses. Ultimately, the goal of these approaches is to gain an in-depth understanding of parasite biology and host immunity, potentially leading to new vaccination and therapeutic strategies against trypanosomosis.

Difluoromethylated Difunctionalization of Alkenes under Visible Light

Difluoromethylated compounds usually act as bioisosteres for alcohol functional groups and show unique physicochemical and biological properties. The cyano-difluoromethylation of alkenes using 5-((difluoromethyl)sulfonyl)-1-phenyl-1H-tetrazole as a CF2H radical difluoromethyl precursor was developed to afford nitriles including a CF2H group. A low-cost, stable, easily handled 5-((difluoromethyl)sulfonyl)-1-methyl-1H-tetrazole (DFSMT) was synthesized and applied as the radical CF2H reagent. Using DFSMT as the radical CF2H precursor, the oxyl-difluoromethylation of alkenes was developed to obtain difluoromethylated ether products. All of the reactions showed good functional group tolerability. Initial mechanistic experiments indicated that the CF2H radical was involved as the key active intermediate.

Efficacy and safety of Dimdazenil in the adult insomnia patients: a phase II randomized, multicenter, double-blind, placebo-controlled, and parallel-group study

STUDY OBJECTIVES

To evaluate the efficacy and safety of Dimdazenil, a positive allosteric modulator with selectivity for α1, α5 subunit-containing GABAA receptors, on sleep variables in patients with insomnia disorder.

METHODS

In this randomized, double-blind, placebo-controlled trial, adults (18-65 years) with insomnia disorder were randomized (1:1:1:1 to receive daily oral placebo, Dimdazenil (1.5, 2.5, or 5 mg) for 14 days. The primary efficacy outcome was the total sleep time (TST) on day 1/2 and day 13/14, measured by polysomnography. The secondary outcome measures included (1) latency to persistent sleep (LPS), sleep efficiency (SE), wake after sleep onset (WASO) and number of awakenings (NAW) on days 1/2 and day 13/14, and (2) the average subjective sleep latency (sSL), total sleep time (sTST), wake after sleep onset (sWASO) and number of awakenings (sNAW) recorded in sleep diary and sleep questionnaire, and the evaluation of insomnia severity index. Rebound insomnia, withdrawal, and treatment-emergent adverse events were also assessed.

RESULTS

Of 569 patients screened, 288 (76.4% female) were randomized and received one dose. For the primary outcomes, TST was significantly improved in the Dimdazenil 1.5, 2.5, and 5 mg group compared with the placebo group at day 1/2, and significantly improved in the Dimdazenil 2.5 and 5 mg groups compared with the placebo group at day 13/14. The Least Squares Means (standard errors) and 95% Confidence Intervals for the three active doses compared to placebo are 25.5 (8.31), (9.16, 41.89) for the 1.5 mg dose; 17.4 (8.19), (1.29, 33.55) for the 2.5 mg dose; 22.8 (8.15), (6.72, 38.80) for the 5 mg dose on day 1/2. Corresponding data on day 13/14 are 7.6 (8.07), (-8.24, 23.53) and 19.3 (8.06), (3.43, 35.17) and 18.2 (7.95), (2.49, 33.80). LPS was significantly reduced in the Dimdazenil 5 mg group compared with the placebo group on day 1/2. SE was significantly improved in the Dimdazenil 1.5 and 5 mg group compared with the placebo group at day 1/2. In the subjective sleep parameters, sSL on average was significantly lower in the Dimdazenil 1.5, 2.5, and 5 mg groups compared with the placebo group. sTST on average was significantly higher in the Dimdazenil 1.5, 2.5, and 5 mg groups compared with the placebo group. The most common TEAEs were dizziness, vertigo, and weakness with no clinically relevant treatment-related serious adverse events.

CONCLUSIONS

Dimdazenil of 1.5, 2.5, and 5 mg improved certain objective and subjective sleep outcomes in people with insomnia disorder, with a favorable safety profile. These findings suggested that Dimdazenil may represent a promising new treatment for insomnia disorder, a prevalent condition with limited effective and safe treatments available.

CLINICAL TRIAL INFORMATION

A multicenter, randomized, double-blind, multidose, placebo parallel controlled phase II clinical study of EVT201 in the treatment of insomnia disorders (http://www.chinadrugtrials.org), with the number of CTR20150664.

Transcranial Direct Current Stimulation (tDCS) Ameliorates Stress-Induced Sleep Disruption via Activating Infralimbic-Ventrolateral Preoptic Projections

Transcranial direct current stimulation (tDCS) is acknowledged for its non-invasive modulation of neuronal activity in psychiatric disorders. However, its application in insomnia research yields varied outcomes depending on different tDCS types and patient conditions. Our primary objective is to elucidate its efficiency and uncover the underlying mechanisms in insomnia treatment. We hypothesized that anodal prefrontal cortex stimulation activates glutamatergic projections from the infralimbic cortex (IL) to the ventrolateral preoptic area (VLPO) to promote sleep. After administering 0.06 mA of electrical currents for 8 min, our results indicate significant non-rapid eye movement (NREM) enhancement in naïve mice within the initial 3 h post-stimulation, persisting up to 16-24 h. In the insomnia group, tDCS enhanced NREM sleep bout numbers during acute stress response and improved NREM and REM sleep duration in subsequent acute insomnia. Sleep quality, assessed through NREM delta powers, remains unaffected. Interference of the IL-VLPO pathway, utilizing designer receptors exclusively activated by designer drugs (DREADDs) with the cre-DIO system, partially blocked tDCS's sleep improvement in stress-induced insomnia. This study elucidated that the activation of the IL-VLPO pathway mediates tDCS's effect on stress-induced insomnia. These findings support the understanding of tDCS effects on sleep disturbances, providing valuable insights for future research and clinical applications in sleep therapy.

Cannabidiol and brain function: current knowledge and future perspectives

Cannabidiol (CBD) is a naturally occurring non-psychoactive cannabinoid found in Cannabis sativa, commonly known as cannabis or hemp. Although currently available CBD products do not meet the safety standards of most food safety authorities to be approved as a dietary supplement or food additive, CBD has been gaining widespread attention in recent years due to its various potential health benefits. While primarily known for its therapeutic effects in managing epileptic seizures, psychosis, anxiety, (neuropathic) pain, and inflammation, CBD's influence on brain function has also piqued the interest of researchers and individuals seeking to enhance cognitive performance. The primary objective of this review is to gather, synthesize, and consolidate scientifically proven evidence on the impact of CBD on brain function and its therapeutic significance in treating neurological and mental disorders. First, basic background information on CBD, including its biomolecular properties and mechanisms of action is presented. Next, evidence for CBD effects in the human brain is provided followed by a discussion on the potential implications of CBD as a neurotherapeutic agent. The potential effectiveness of CBD in reducing chronic pain is considered but also in reducing the symptoms of various brain disorders such as epilepsy, Alzheimer's, Huntington's and Parkinson's disease. Additionally, the implications of using CBD to manage psychiatric conditions such as psychosis, anxiety and fear, depression, and substance use disorders are explored. An overview of the beneficial effects of CBD on aspects of human behavior, such as sleep, motor control, cognition and memory, is then provided. As CBD products remain largely unregulated, it is crucial to address the ethical concerns associated with their use, including product quality, consistency, and safety. Therefore, this review discusses the need for responsible research and regulation of CBD to ensure its safety and efficacy as a therapeutic agent for brain disorders or to stimulate behavioral and cognitive abilities of healthy individuals.

Different Doses of Dexmedetomidine Reduce Postoperative Sleep Disturbance Incidence in Patients under General Anesthesia by Elevating Serum Neurotransmitter Levels

Postoperative sleep disturbance is a common issue that affects recovery in patients undergoing general anesthesia. Dexmedetomidine (Dex) has a potential role in improving postoperative sleep quality. We evaluated the effects of different doses of Dex on postoperative sleep disturbance and serum neurotransmitters in patients undergoing radical gastrectomy under general anesthesia. Patients were assigned to the control, NS, and Dex (Dex-L/M/H) groups based on different treatment doses [0.2, 0.4, and 0.6 μg/(kg · h)]. The Athens Insomnia Scale (AIS) and ELISA kits were used to assess sleep disturbance and serum neurotransmitter (GABA, 5-HT, NE) levels before surgery and on postoperative days one, four, and seven. The effects of different doses on postoperative sleep disturbance incidence and serum neurotransmitter levels were analyzed by the Fisher exact test and one-way and repeated-measures ANOVA. Patients had no differences in gender, age, body mass index, operation time, and bleeding volume. Different Dex doses reduced the postoperative AIS score of patients under general anesthesia, improved their sleep, and increased serum levels of 5-HT, NE, and GABA. Furthermore, the effects were dose-dependent within the range of safe clinical use. Specifically, Dex at doses of 0.2, 0.4, and 0.6 μg/(kg · h) reduced postoperative AIS score, elevated serum neurotransmitter levels, and reduced postoperative sleep disturbance incidence. Collectively, Dex has a potential preventive effect on postoperative sleep disturbance in patients undergoing general anesthesia for radical gastrectomy. The optimal dose of Dex is between 0.2 and 0.6 μg/(kg · h), which significantly reduces the incidence of postoperative sleep disturbance and increases serum neurotransmitter levels.

Effects of Prebiotic Yeast Mannan on Gut Health and Sleep Quality in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study

Human gut health is closely related to sleep. We aimed to evaluate the efficacy of yeast mannan (YM) in improving bowel habits and sleep quality, along with metabolomics in fecal samples. A total of 40 healthy adults (age range, 22-64 years) with discomfort in defecation were enrolled and randomly allocated to receive either YM (n = 20; 1.1 g/day) or placebo (n = 20) for four weeks. Participants recorded their defecation habits throughout the test periods. Sleep electroencephalogram (EEG) recording using an EEG device and fecal sampling were performed pre- and post-treatment. The YM group significantly increased defecation frequency and stool volumes compared to the placebo group. After 4 weeks of treatment, the non-REM sleep stage 3 (N3) duration in the YM group was significantly higher than that in the placebo group. YM ingestion significantly lengthened total time in bed (TIB) and significantly shortened N3 latency compared to placebo intake during the trial. The metabolomics analysis found a total of 20 metabolite differences between the YM and placebo groups. As a result of stepwise linear regression, changes in fecal propionate and gamma-aminobutyric acid (GABA) levels were identified as the primary factors explaining changes in TIB and N3 latency, respectively. Our findings suggest that the prebiotic YM could be beneficial to gut health and sleep quality.

The relationship between sleep, gut microbiota, and metabolome in patients with depression and anxiety: A secondary analysis of the observational study

BACKGROUND

Growing attention is paid to the association between alterations in the gut microbiota and their metabolites in patients with psychiatric disorders. Our study aimed to determine how gut microbiota and metabolomes are related to the sleep quality among patients with depression and anxiety disorders by analyzing the datasets of our previous study.

METHODS

Samples were collected from 40 patients (depression: 32 patients [80.0%]); anxiety disorders: 8 patients [20.0%]) in this study. Gut microbiomes were analyzed using 16S rRNA gene sequencing and gut metabolomes were analyzed by a mass spectrometry approach. Based on the Pittsburgh Sleep Quality Index (PSQI), patients were categorized into two groups: the insomnia group (PSQI score ≥ 9, n = 20) and the non-insomnia group (PSQI score < 9, n = 20).

RESULTS

The insomnia group showed a lower alpha diversity in the Chao1 and Shannon indices than the non-insomnia group after the false discovery rate (FDR) correction. The relative abundance of genus Bacteroides showed a positive correlation with PSQI scores in the non-insomnia group. The concentrations of glucosamine and N-methylglutamate were significantly higher in the insomnia group than in the non-insomnia group.

CONCLUSIONS

Our findings suggest that specific taxa could affect the sleep quality among patients with depression and anxiety disorders. Further studies are needed to elucidate the impact of sleep on specific gut microbiota and metabolomes in depression and anxiety disorders.

Prolonged Zaleplon Treatment Increases the Expression of Proteins Involved in GABAergic and Glutamatergic Signaling in the Rat Hippocampus

Zaleplon is a positive allosteric modulator of the γ-aminobutyric acid (GABA)A receptor approved for the short-term treatment of insomnia. Previous publications on zaleplon have not addressed the proteins involved in its mechanism of action but have mostly referred to behavioral or pharmacological studies. Since both GABAergic and glutamatergic signaling have been shown to regulate wakefulness and sleep, we examined the effects of prolonged zaleplon treatment (0.625 mg/kg for 5 days) on these systems in the hippocampus of male Wistar rats. Western blot and immunohistochemical analyses showed that the upregulated components of GABAergic signaling (glutamate decarboxylase, vesicular GABA transporter, GABA, and α1 subunit of the GABAA receptor) were accompanied by increased protein levels in the glutamatergic system (vesicular glutamate transporter 1 and NR1, NR2A, and NR2B subunits of N-methyl-d-aspartate receptor). Our results, showing that zaleplon enhances GABA neurotransmission in the hippocampus, were not surprising. However, we found that treatment also increased glutamatergic signaling. This could be the result of the downregulation of adenosine A1 receptors, important modulators of the glutamatergic system. Further studies are needed to investigate the effects of the zaleplon-induced increase in hippocampal glutamatergic neurotransmission and the possible involvement of the adenosine system in zaleplon's mechanism of action.

The possible "calming effect" of subchronic supplementation of a standardised phospholipid carrier-based Melissa officinalis L. extract in healthy adults with emotional distress and poor sleep conditions: results from a prospective, randomised, double-blinded, placebo-controlled clinical trial

Background: Emotional distress conditions such as depression, anxiety, stress, and poor sleep are widespread health problems that have a significant impact on people's lives. Conventional drugs are commonly prescribed to treat emotional distress and poor sleep conditions; however, these medications have several limitations and have shown multiple side effects. Over recent years botanicals-based pharmacological agents have gained increasing research and clinical interest in the management of emotional distress and sleep disorder. Of note, Melissa officinalis L. (MO) leaf extract has demonstrated considerable neuropharmacological properties both in animal and human studies and has emerged as a promising natural "calming agent." However, research in this area is limited, and more studies are needed to validate its efficacy in amelioration of emotional distress and poor sleep conditions. Objectives: We aimed to assess the pharmacological effects of subchronic supplementation of an innovative standardised phospholipid carrier-based MO aqueous extract on emotional distress and poor sleep conditions. Design: A 3-week prospective, randomised, placebo-controlled, parallel-group, double-blinded clinical trial was conducted in 100 healthy adults complaining of a moderate degree of depression, anxiety, or stress, with scores of ≥14, ≥10, and ≥19, respectively, in the self-report Depression, Anxiety, and Stress Scale (DASS-42) or poor sleep, as indicated by the score of >5 in the Pittsburgh Sleep Quality Index (PSQI) scale. In addition, the impact of emotional distress and/or poor sleep on participants' mental wellbeing, emotional feelings, and quality of life was also assessed using the self-reported Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS), Positive and Negative Affect Schedule (PANAS) scale, and quality of life (WHO-QoL-BREF) scale, respectively. Results: Oral supplementation of 200 mg of phospholipid-based MO aqueous extract (Relissa™) tablets twice a day (i.e., 400 mg/day) for 3 weeks led to significant improvements in the depressive mood, anxiety, stress, positive and negative affect (emotional feelings), overall mental wellbeing, and quality-of-life scores (all p values <0.001). Supplementation of MO extract was well tolerated, and no treatment-emergent effects or serious adverse events were reported. Conclusion: According to the results of this study, the phospholipid carrier-based MO aqueous extract possesses considerable neuropharmacological properties, and its supplementation may provide a promising therapeutic option for the management of moderate emotional distress and/or poor sleep conditions. Clinical Trial Registration: clinicaltrials.gov, identifier NCT05602688.

Sex hormone dose escalation for treating abnormal sleep in ovariectomized rats: in vitro GABA synthesis in sleep-related brain areas

No data in the literature have evaluated sex hormone dose escalation for treating abnormal sleep of ovariectomized rats-nor studies on the role of sex hormones in GABA synthesis of rats' sleep-related areas. The main aim of this study was to determine the maximum tolerated dose (MTD) of estradiol (ET), progesterone (PT), and the mixture of both (EPT) to restore normal sleep in a model of menopause in rats. The second purpose was to describe the in vitro activity of glutamate decarboxylase (GAD) in sleep-related brain areas in the presence or absence of sex hormones. A weekly dose-escalation design of ET, PT, or EPT was implemented in ovariectomized rats (six per group). Dose escalation continued until the dose at which 100% of the rats exhibited a state of "complete somnolence." Doses that were not toxic or did not show side effects were considered. For in vitro experiments, sleep-related brain areas were separated and incubated with radiolabeled glutamate. Estradiol (17β-E2), progesterone (P), and pyridoxal phosphate (PLP) were added to this assay, and GAD activity was determined. Under the same conditions, a second test was carried out, but the P antagonist RU486 was added to assess the role of P in GAD activity. Ovariectomy increased periodic awakenings compared to those determined for the SHAM group. The EPT for ovariectomized rats was very effective by the fifth week in decreasing arousal and achieving a similar sleep behavior to the SHAM-control group. Rats tolerated the ET, PT, and EPT well to the maximum planned dose (0.66 mg/kg and 4.4 mg/kg, respectively). No lethal events occurred; the MTD was reached. The in vitro studies indicated that the presence of 17β-E2 plus P in the assay triggered the activity of isotype 65 GAD in all the studied brain areas. RU486 in the incubation medium blocked such activity; however, the action of isotype 67 GAD was not blocked by RU486. A dose-escalation model was determined; the MTD coincided with the maximum dose of ET and PT used. However, the EPT combination restored normal sleep in the menopause model compared to the SHAMs without toxic effects. The in vitro model demonstrated that 17β-E2 plus P presence in the assay increased the activity of GAD65 in the studied brain tissues.

Polymorphism and Multi-Component Crystal Formation of GABA and Gabapentin

This study exploits the polymorphism and multi-component crystal formation of γ-amino butanoic acid (GABA) and its pharmaceutically active derivative, gabapentin. Two polymorphs of GABA and both polymorphs of gabapentin are structurally revisited, together with gabapentin monohydrate. Hereby, GABA form II is only accessible under special conditions using additives, whereas gabapentin converts to the monohydrate even in the presence of trace amounts of water. Different accessibilities and phase stabilities of these phases are still not fully clarified. Thus, indicators of phase stability are discussed involving intermolecular interactions, molecular conformations, and crystallization environment. Calculated lattice energy differences for polymorphs reveal their similar stability. Quantification of the hydrogen bond strengths with the atoms-in-molecules (AIM) model in conjunction with non-covalent interaction (NCI) plots also shows similar hydrogen bond binding energy values for all polymorphs. We demonstrate that differences in the interacting modes, in an interplay with the intermolecular repulsion, allow the formation of the desired phase under different crystallization environments. Salts and co-crystals of GABA and gabapentin with fumaric as well as succinic acid further serve as models to highlight how strongly HBs act as the motif-directing force in the solid-phase GABA-analogs. Six novel multi-component entities were synthesized, and structural and computational analysis was performed: GABA fumarate (2:1); two gabapentin fumarates (2:1) and (1:1); two GABA succinates (2:1) and (1:1); and a gabapentin:succinic acid co-crystal. Energetically highly attractive carboxyl/carboxylate interaction overcomes other factors and dominates the multi-component phase formation. Decisive commonalities in the crystallization behavior of zwitterionic GABA-derivatives are discussed, which show how they can and should be understood as a whole for possible related future products.

D’Adamo C, Rosner B, Chen J, Pauli EK. A Randomized, Double-Blind, Placebo-Controlled Decentralized Trial to Assess Sleep, Health Outcomes, and Overall Well-Being in Healthy Adults Reporting Disturbed Sleep, Taking a Melatonin-Free Supplement

Inadequate sleep is a global health concern. Sleep is multidimensional and complex; new multi-ingredient agents are needed. This study assessed the comparative effects of two multi-ingredient supplements on sleep relative to placebo. Adults (N = 620) seeking better sleep were randomly assigned to receive one of three study products. Sleep A (contained lower (0.35 mg THC and higher levels of botanicals (75 mg each hops oil and valerian oil), Sleep B (contained higher THC (0.85 mg) and lower botanicals (20 mg each hops oil and valerian oil) or placebo) for 4 weeks. Sleep disturbance was assessed at baseline and weekly using NIH's Patient-Reported Outcomes Measurement Information System (PROMIS™) Sleep Disturbance SF 8A survey. Anxiety, stress, pain, and well-being were assessed using validated measures at baseline and weekly. A linear mixed-effects regression model was used to assess the change in health outcome score between active product groups and the placebo. There was a significant difference in sleep disturbance, anxiety, stress, and well-being between Sleep A and placebo. There was no significant difference in any health parameter between Sleep B and placebo. Side effects were mild or moderate. There were no significant differences in the frequency of side effects between the study groups. A botanical blend containing a low concentration of THC improved sleep disturbance, anxiety, stress, and well-being in healthy individuals that reported better sleep as a primary health concern.

Integrating animal experiments, mass spectrometry and network-based approach to reveal the sleep-improving effects of Ziziphi Spinosae Semen and γ-aminobutyric acid mixture

BACKGROUND

Ziziphi Spinosae Semen (ZSS) is a plant widely used as medicine and food in Asian countries due to its numerous health benefits. γ-aminobutyric acid (GABA), a non-proteinaceous amino acid, is one of the major inhibitory neurotransmitters with a relaxant function. In this study, a system pharmacology approach was employed to assess the effects of a mixture composed of ZSS and GABA (ZSSG) on sleep improvement.

METHODS

Mice were divided into five groups (n = 10) and received either no treatment, sodium pentobarbital, or sodium barbital with diazepam or ZSSG. The effects of ZSSG on sleep quality were evaluated in mice, and differential metabolites associated with sleep were identified among the control, ZSS, GABA, and ZSSG groups. Additionally, network-based ingredient-insomnia proximity analysis was applied to explore the major ingredients.

RESULTS

ZSSG significantly improved sleep quality by decreasing sleep latency and prolonging sleep duration in sodium pentobarbital-induced sleeping mouse model (P < 0.05). ZSSG significantly enhanced the brain content of GABA in mice. Furthermore, ZSSG also significantly decreased sleep latency-induced by sodium barbital in mice (P < 0.05). Metabolic analysis revealed significant differences in 10 metabolites between ZSSG group and the groups administering ZSS or GABA. Lastly, using the network-based ingredient screening model, we discovered potential four active ingredients and three pairwise ingredient combinations with synergistic effect on insomnia from ZSSG among 85 ingredients identified by UPLC-Q/TOF-MS. Also, we have constructed an online computation platform.

CONCLUSION

Our data demonstrated that ZSSG improved the sleeping quality of mice and helped to balance metabolic disorders-associated with sleep disorders. Moreover, based on the network-based prediction method, the four potential active ingredients in ZSSG could serve as quality markers-associated with insomnia. The network-based framework may open up a new avenue for the discovery of active ingredients of herbal medicine for treating complex chronic diseases or symptoms, such as insomnia.

Metabolites Potentially Determine the High Antioxidant Properties of Limosilactobacillus fermentum U-21

Many kinds of Lactobacillus are common occupants of humans' digestive tract that support the preservation of a balanced microbial environment that benefits host health. In this study, the unique lactic acid bacterium strain Limosilactobacillus fermentum U-21, which was isolated from the feces of a healthy human, was examined for its metabolite profile in order to compare it to that of the strain L. fermentum 279, which does not have antioxidant (AO) capabilities. By using GC × GC-MS, the metabolite fingerprint of each strain was identified, and the data were then subjected to multivariate bioinformatics analysis. The L. fermentum U-21 strain has previously been shown to possess distinctive antioxidant properties in in vivo and in vitro studies, positioning it as a drug candidate for the treatment of Parkinsonism. The production of multiple distinct compounds is shown by the metabolite analysis, demonstrating the unique characteristics of the L. fermentum U-21 strain. According to reports, some of the L. fermentum U-21 metabolites found in this study have health-promoting properties. The GC × GC-MS-based metabolomic tests defined strain L. fermentum U-21 as a potential postbiotic with significant antioxidant potential.

Association between sleep slow-wave activity and in-vivo estimates of myelin in healthy young men

Sleep has been suggested to contribute to myelinogenesis and associated structural changes in the brain. As a principal hallmark of sleep, slow-wave activity (SWA) is homeostatically regulated but also differs between individuals. Besides its homeostatic function, SWA topography is suggested to reflect processes of brain maturation. Here, we assessed whether interindividual differences in sleep SWA and its homeostatic response to sleep manipulations are associated with in-vivo myelin estimates in a sample of healthy young men. Two hundred twenty-six participants (18-31 y.) underwent an in-lab protocol in which SWA was assessed at baseline (BAS), after sleep deprivation (high homeostatic sleep pressure, HSP) and after sleep saturation (low homeostatic sleep pressure, LSP). Early-night frontal SWA, the frontal-occipital SWA ratio, as well as the overnight exponential SWA decay were computed over sleep conditions. Semi-quantitative magnetization transfer saturation maps (MTsat), providing markers for myelin content, were acquired during a separate laboratory visit. Early-night frontal SWA was negatively associated with regional myelin estimates in the temporal portion of the inferior longitudinal fasciculus. By contrast, neither the responsiveness of SWA to sleep saturation or deprivation, its overnight dynamics, nor the frontal/occipital SWA ratio were associated with brain structural indices. Our results indicate that frontal SWA generation tracks inter-individual differences in continued structural brain re-organization during early adulthood. This stage of life is not only characterized by ongoing region-specific changes in myelin content, but also by a sharp decrease and a shift towards frontal predominance in SWA generation.

β-asarone prolongs sleep via regulating the level of glutamate in the PVN

People of all ages could suffer from sleep disorders, which are increasingly recognized as common manifestations of neurologic disease. Acorus tatarinowii is a herb that has been used in traditional medicine to promote sleep. β-asarone, as the main component of volatile oil obtained from Acorus tatarinowii, may be the main contributor to the sleeping-promoting efficacy of Acorus tatarinowii. In the study, adult male C57BL/6 mice were administered β-asarone at 12.5 mg/kg, 25 mg/kg, and 50 mg/kg. Behavioral experiments showed that β-asarone at 25 mg/kg could significantly improve sleep duration. It was also observed that the proportion of NREM (Non-Rapid Eye Movement) sleep increased considerably after administration of β-asarone. In the PVN (paraventricular nucleus of hypothalamus) region of the hypothalamus, it was observed that the glutamate content decreased after β-asarone treatment. At the same time, the expression of VGLUT2 (vesicular glutamate transporters 2) decreased while the expression of GAD65 (glutamic acid decarboxylase 65) and GABARAP (GABA Type A Receptor-Associated Protein) increased in the hypothalamus, suggesting that β-asarone may suppress arousal by reducing glutamate and promoting transformation of glutamate to the inhibitory neurotransmitter GABA (γ-aminobutyric acid). This study is the first to focus on the association between β-asarone and sleep, shedding perspectives for pharmacological applications of β-asarone and providing a new direction for future research.

Protocol for a pilot and feasibility randomized-controlled trial of four weeks of oral γ-aminobutyric acid (GABA) intake and its effect on pain and sleep in middle-to-older aged adults

Approximately 1.71 billion people globally live with musculoskeletal pain conditions, including low back pain, knee pain, and neck pain Cieza et al. (2020). In the US, an estimated 20.4% of U.S. adult had chronic pain and 8.0% of U.S. adults had high-impact chronic pain, with higher prevalence associated with advancing age Dahlhamer et al. (2018). On the other hand, between 50 and 70 million US adults have a sleep disorder (American Sleep Association). Although the link between sleep and pain is widely established, the neurobiological mechanisms underlying this relationship have yet to be fully elucidated, specifically within an aged population. As currently available sleep and chronic pain therapies are only partially effective, novel treatment approaches are urgently needed. Given the potential mechanistic role of γ-aminobutyric acid (GABA) in both conditions, and the availability of GABA supplements over the counter, the present proposal will determine the feasibility and acceptability of oral GABA administration in middle-to-older aged adults with chronic pain and sleep disorders as well as characterize the potential neurobiological mechanisms involved in both conditions. Results from the present investigation using a parallel, double-blinded, placebo-controlled study will provide novel preliminary information needed for future translational pain and sleep research.