Curcuminoids, a major turmeric component, have a sleep-enhancing effect by targeting the histamine H1 receptor.

Turmeric (Curcuma longa) had been considered as a universal panacea in functional foods and traditional medicines. In recent, the sedative-hypnotic effect of turmeric extract (TE) was reported. However, sleep-promoting compounds in TE have been not yet demonstrated. Curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) are the major constituents of turmeric being responsible for its various biological activities. Therefore, they can be first assumed to be sedative-hypnotic compounds of TE. In the present study, we aimed to investigate the effects and underlying mechanisms of curcuminoids and each constituent on the sleep-wake cycle of mice. Molecular docking studies, histamine H1 receptor (H1R) binding assays, and H1R knockout animal studies were used to investigate the molecular mechanisms underlying the sleep-promoting effects. Curcuminoids and their constituents reduced sleep latency and increased sleep duration in the pentobarbital-induced sleep test in mice. In addition, curcuminoids significantly increased the duration of NREMS and reduced sleep latency without altering the REMS and delta activity. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin were predicted to interact with H1R in the molecular model. In the binding affinity assay, we found that curcuminoids, as well as their constituents, significantly bind to H1R with the Ki value of 1.49 µg mL-1. Furthermore, sleep latency was reduced and NREMS frequency was increased following curcuminoid administration in wild-type mice but not in H1R knockout mice. Therefore, we conclude that curcuminoids reduce sleep latency and enhance the quantity of NREMS by acting as modulators of H1R, indicating their usefulness in treating insomnia.

Effects of propofol on sleep architecture and sleep-wake systems in rats.

Previous studies have shown that the synchronization of electroencephalogram (EEG) signals is found during propofol-induced general anesthesia, which is similar to that of slow-wave sleep (SWS). However, a complete understanding is lacking in terms of the characteristics of EEG changes in rats after propofol administration and whether propofol acts through natural sleep circuits. Here, we examined the characteristics of EEG patterns induced by intraperitoneal injection of propofol in rats. We found that high (10 mg/kg) and medium (5 mg/kg) doses of propofol induced a cortical EEG of low-frequency, high-amplitude activity with rare electromyographic activity and markedly shortened sleep latency. The high dose of propofol increased deep slow-wave sleep (SWS2) to 4 h, as well as the number of large SWS2 bouts (>480 s), their mean duration and the peak of the power density curve in the delta range of 0.75-3.25 Hz. After the medium dose of propofol, the total number of wakefulness, light slow-wave sleep (SWS1) and SWS2 episodes increased, whereas the mean duration of wakefulness decreased. The high dose of propofol significantly increased c-fos expression in the ventrolateral preoptic nucleus (VLPO) sleep center and decreased the number of c-fos-immunoreactive neurons in wake-related systems including the tuberomammillary nucleus (TMN), perifornical nucleus (PeF), lateral hypothalamic nucleus (LH), ventrolateral periaqueductal gray (vPAG) and supramammillary region (SuM). These results indicated that the high dose of propofol produced high-quality sleep by increasing SWS2, whereas the medium dose produced fragmented and low-quality sleep by disrupting the continuity of wakefulness. Furthermore, sleep-promoting effects of propofol are correlated with activation of the VLPO cluster and inhibition of the TMN, PeF, LH, vPAG and SuM.

A Novel Potent Sleep-Promoting Effect of Turmeric: Turmeric Increases Non-Rapid Eye Movement Sleep in Mice Via Histamine H1Receptor Blockade.

SCOPE: Turmeric has a broad spectrum of biological properties; however, the sleep-promoting effects of turmeric have not yet been reported. Thus, this study aims to investigate the effect of turmeric on sleep and the molecular mechanism underlying this effect. METHODS AND RESULTS: Pentobarbital-induce sleep test and sleep-wake profile assessment using recorded electroencephalography are used to evaluate the hypnotic effects of the turmeric extract (TE) compared to diazepam on sleep in mice. Additionally, the molecular mechanism of TE's sleep effect is investigated using ex vivo electrophysiological recordings from brain slices in histamine H1 receptor (H1 R) knockout mice. Oral administration of TE and diazepam significantly reduce sleep latency and increase non-rapid eye movement sleep (NREMS) duration without delta activity in mice. Like doxepin, TE inhibits the H1 R agonist (2-pyridylethylamine dihydrochloride)-induced increase in action potentials in the hypothalamic neurons. In animal tests using neurotransmitter agonists or antagonists, TE effect mimick H1 R antagonistic effect of doxepin. Additionally, both reduce sleep latency and increase NREMS in wild-type mice, although these effects are not observed in H1 R knockout mice. CONCLUSION: TE has a sleep-promoting effect owing to reduction in sleep latency and enhancement of NREMS via H1 R blockade; therefore, it could be useful in insomnia.

Efficacy of Triprolidine in the Treatment of Temporary Sleep Disturbance.

Triprolidine, a first-generation antihistamine for allergic rhinitis, has a shorter half-life and fewer persistent effects relative to other antihistamines and may be useful in the treatment of temporary sleep disturbance. Patients aged ≥18 years old were randomized 1:1:1 to receive either triprolidine 2.5 mg (n = 65), triprolidine 5 mg (n = 66), or placebo (n = 67) on 3 consecutive nights. Sleep disturbance index was monitored via wrist actimeter. Subjective measures were assessed via diary card. Triprolidine 2.5 mg had a significantly lower sleep disturbance index versus placebo on night 1 (P = .02); however, when adjusted for outliers, sleep disturbance index did not significantly differ between either dose of triprolidine versus placebo on night 1. Adjusted sleep disturbance index was significantly lower with triprolidine 2.5 and 5 mg versus placebo on night 3 (P = .0017 and P = .011, respectively) and for the mean of all 3 nights (P = .01 and P = .015, respectively). Sleep latency was significantly improved for triprolidine 2.5 mg versus placebo on nights 2 and 3 and for the mean of all 3 nights and for triprolidine 5 mg versus placebo for the mean of all 3 nights. Subjective measures showed those on both doses of triprolidine felt more refreshed on awakening versus placebo for the mean of all 3 nights, with no increase in daytime sleepiness. The frequency of adverse events was similar across groups. The optimum dose of triprolidine for treatment of temporary sleep disturbance was 2.5 mg. There were improvements in both objective and subjective measures of sleep quality versus placebo, with no safety concerns raised.

Anticonvulsant effects of the aqueous and methanol extracts from the stem bark of Psychotria camptopus Verdc. (Rubiacaea) in rats.

ETHNOPHARMACOLOGY RELEVANCE: The decoction from the stem bark of Psychotria camptopus (Rubiaceae) is used in the Cameroonian pharmacopoeia to treat neurological pathologies including epilepsy. AIM: The present work was undertaken to study the anticonvulsant properties of the aqueous (AE) and methanol (ME) extracts from the stem bark of P. camptopus in acute models of epileptic seizures in Wistar rats. METHOD: AE and ME were obtained by decoction and maceration of the stem bark powder in water and methanol, respectively. They were tested orally at the doses of 40, 80 and 120 mg/kg, on the latency of onset and duration of epileptic seizures induced by pentylene tetrazole (PTZ, 70 mg/kg, i.p.). The kinetic effect of both extracts at 120 mg/kg was evaluated. Their effects on diazepam (50 mg/kg) induced sleep and strychnine (STR, 2.5 mg/kg, i.p.) induced seizures were determined. ME was further tested on picrotoxin (PIC, 7.5 mg/kg, i.p.) and thiosemicarbazide (TSC, 50 mg/kg, i.p.) induced seizure models. The phytochemical composition of ME was assessed using LC-MS method, as well as its acute toxicity. RESULTS: AE and ME significantly (p < 0.001) reduced the duration of seizures in both PTZ and STR models. Their maximal effect was observed at 1 h after administration, though their effect at 120 mg/kg was maintained (p < 0.05) up to 24 h post-treatment. Both extracts significantly (p < 0.01) reduced sleep duration. ME significantly (p < 0.001) increased the latency of rat death on PIC-induced convulsions. In TSC rats, ME significantly (p < 0.001) delayed the latency to the first convulsion, and decreased the duration and frequency of convulsions. ME showed no acute toxicity while its phytochemical screening revealed the presence of two flavonoids (Rutin and Butin), two triterpenoid saponins (Psycotrianoside B and Bauerenone) and four alkaloids (10-Hydroxy-antirhine, 10-hydroxy-iso-deppeaninol, Emetine and Hodkinsine). In conclusion, AE and ME from the stem bark of P. camptopus have comparable anticonvulsant properties. The effect of ME is likely due to the presence of flavonoids and alkaloid and the activation of GABA pathway. These results further justify and support the use of P. camptopus in traditional medicine for the treatment of epilepsy.

Melatonin: From Pharmacokinetics to Clinical Use in Autism Spectrum Disorder.

The role of melatonin has been extensively investigated in pathophysiological conditions, including autism spectrum disorder (ASD). Reduced melatonin secretion has been reported in ASD and led to many clinical trials using immediate-release and prolonged-release oral formulations of melatonin. However, melatonin's effects in ASD and the choice of formulation type require further study. Therapeutic benefits of melatonin on sleep disorders in ASD were observed, notably on sleep latency and sleep quality. Importantly, melatonin may also have a role in improving autistic behavioral impairments. The objective of this article is to review factors influencing treatment response and possible side effects following melatonin administration. It appears that the effects of exposure to exogenous melatonin are dependent on age, sex, route and time of administration, formulation type, dose, and association with several substances (such as tobacco or contraceptive pills). In addition, no major melatonin-related adverse effect was described in typical development and ASD. In conclusion, melatonin represents currently a well-validated and tolerated treatment for sleep disorders in children and adolescents with ASD. A more thorough consideration of factors influencing melatonin pharmacokinetics could illuminate the best use of melatonin in this population. Future studies are required in ASD to explore further dose-effect relationships of melatonin on sleep problems and autistic behavioral impairments.

Nelumbo nucifera promotes non-rapid eye movement sleep by regulating GABAergic receptors in rat model.

ETHNOPHARMACOLOGICAL RELEVANCE: Nelumbo nucifera are used in folk medicine for anti-depressant, anti-convulsant, neuroprotective, and many other purposes. AIM OF THE STUDY: The present work evaluated the sleep potentiating effects of water extract from lotus seed in rat, and the neuropharmacological mechanisms underlying these effects. MATERIALS AND METHODS: Pentobarbital-induced sleep test and electroencephalogram (EEG) analysis were applied to investigate sleep latency, duration, total sleeping time and sleep quality of Lotus extract. In addition, real-time PCR and HPLC analysis were applied to analyze the signaling pathway. RESULTS: We found that the amounts of the possible active compounds GABA (2.33 mg/g) and L-tryptophan (2.00 mg/g) were higher than quinidine (0.55 mg/g) and neferine (0.16 mg/g) in lotus seed extract. High dose (160 mg/kg) administration of lotus extract led to a tendency towards decreased sleep latency time and an increase in sleep duration time compared to the control group in a pentobarbital-induced sleep model (p < 0.05). After high dose administration, total sleep and NREM were significantly increased compared to control, while wake time and REM were significantly decreased. Lotus extract-treated rats showed significantly reduced wake time and increased sleep time in a caffeine-induced model of arousal. The transcription level of GABAA receptor, GABAB receptor, and serotonin receptor tended to increase with dose, and lotus extract showed a strong dose-dependent binding capacity to the GABAA receptor. CONCLUSION: The above results strongly suggest that GABA contained in lotus seed extract acts as a sleep potentiating compound, and that sleep-potentiating activity involves GABAA receptor binding.

Effects of Tangerine Essential Oil on Brain Waves, Moods, and Sleep Onset Latency.

Tangerine (Citrus tangerina) is one of the most important crops of Thailand with a total harvest that exceeds 100,000 tons. Citrus essential oils are widely used as aromatherapy and medicinal agents. The effect of tangerine essential oil on human brain waves and sleep activity has not been reported. In the present study, we therefore evaluated these effects of tangerine essential oil by measurement of electroencephalography (EEG) activity with 32 channel platforms according to the international 10-20 system in 10 male and 10 female subjects. Then the sleep onset latency was studied to further confirm the effect on sleep activity. The results revealed that different concentrations, subthreshold to suprathreshold, of tangerine oil gave different brain responses. Undiluted tangerine oil inhalation reduced slow and fast alpha wave powers and elevated low and mid beta wave powers. The subthreshold and threshold dilution showed the opposite effect to the brain compared with suprathreshold concentration. Inhalation of threshold concentration showed effectively decreased alpha and beta wave powers and increased theta wave power, which emphasize its sedative effect. The reduction of sleep onset latency was confirmed with the implementation of the observed sedative effect of tangerine oil.

Is time elapsed between cannabis use and sleep start time associated with sleep continuity? An experience sampling method.

BACKGROUND: A substantial proportion of people using cannabis report using it to improve sleep. Yet, little research exists on the associations between the timing of cannabis use and sleep. This study examines the time elapsed between cannabis use and sleep start time and its association with two of the main indicators of sleep continuity: (1) sleep onset latency (SOL) and (2) number of awakenings (NOA) throughout the night. METHODS: Each morning, for 7 consecutive days, daily cannabis users (n = 54) reported on the timing of previous night's cannabis use and sleep indicators on their smartphones. Mixed effects models examined the relations of within- and between-subjects' time elapsed between previous night cannabis use and sleep start time, with (1) SOL and (2) NOA. RESULTS: Within subjects, shorter time elapsed between cannabis use and sleep start time was associated with shorter SOL (ß = 0.519, p = 0.010), but not NOA (ß = -0.030, p = 0.535). Furthermore, between individuals, the time gap between the previous night cannabis use and sleep start time was not associated with SOL or NOA (p > 0.05). CONCLUSIONS: It is possible that cannabis use proximal to bedtime is associated with shorted sleep onset latency but not nighttime awakenings. Cannabis users should be informed about both the potential sleep aid effects of cannabis and its limitations. Pending further evidence of the effects of cannabis on sleep, cannabis users experiencing sleep problems should be provided with evidence-based alternatives to improve sleep, e.g., pharmacological and behavioral treatments.

A Pilot Crossover Trial of Sleep Medications for Sleep-disturbed Methadone Maintenance Patients.

OBJECTIVES: Problems with sleep are a common and detrimental occurrence among individuals who receive methadone maintenance for opioid use disorder (OUD). METHODS: We enrolled ten methadone-maintained persons with insomnia (60% female, mean age 40) in a double-blind trial using actigraphy to confirm daily sleep reports. After a no-medication week to establish baseline sleep patterns, each participant received 1 week each of mirtazapine (30 mg), zolpidem (sustained-release 12.5 mg), mirtazapine (30 mg IR) plus zolpidem (10 mg), and placebo, with a washout week between each medication week. Study medication order was randomized so that the order of each 1-week medication treatment was different for each participant, but all participants received all 4 regimens. RESULTS: We found that mirtazapine alone improved total sleep (mean 23 minutes), sleep latency (mean 23 minutes), and sleep efficiency (mean 3%), surpassing the other regiments. CONCLUSIONS: This pilot work suggests that mirtazapine is worthy of further testing as a sleep aid for persons with OUD receiving methadone maintenance.

Analgesic, anti-inflammatory and sedative/hypnotic effects of Icaritin, and its effect on chloride influx in mouse brain cortical cells.

Inflammation and insomnia are medical problems that may severely affect work and health, thereby necessitating strategies for their effective treatment. Icartin (ICT) is a major active monomeric component of icariin  . Studies have revealed that ICT possesses several pharmacological properties such anti-inflammatory, anti-tumor, anti-fibrotic, anti-osteoporotic and neuroprotective effects. The present research was carried out to investigate the anti-inflammatory, analgesic and sedative/hypnotic effects of ICT. The results obtained revealed that ICT exerted a good anti-inflammatory effect related to the downregulations of inflammatory cytokines and the inhibition of COX-2 signaling pathway. Moreover, ICT enhanced Cl- influx in mouse cortical cells in a concentration-dependent manner. These data suggest that ICT exerts a hypnotic effect in mice through a mechanism associated with increased Cl- influx in cortical cells.

Eszopiclone for the treatment of primary insomnia: a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials.

STUDY OBJECTIVE: In this study, we performed a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials to evaluate the efficacy and safety of eszopiclone for the treatment of primary insomnia. METHODS: We searched MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials and PubMed from inception to June 2018. Additionally, we searched the ClinicalTrials.gov trials register for other relevant trials. According to participants, intervention, comparison, outcome (PICO) criteria, studies were included that focused on: adults diagnosed with primary insomnia, aged 18-65 and > 65 years; eszopiclone for the treatment of primary insomnia; comparison were made between eszopiclone and placebo; as well as primary outcomes, secondary outcomes, and adverse effects. RESULTS: A total of six randomized trials involving 2809 patients with primary insomnia were included in our analysis. Our analysis suggested that eszopiclone was associated with significant improvements in subjective sleep latency, wake after sleep onset, number of awakenings, total sleep time at one week, two weeks, one month, three months and six months. Meanwhile, eszopiclone was associated with increased quality of sleep, ability to function, daytime alertness and sense of physical well-being at one week, one month, three months and six months. Dizziness and unpleasant taste were the most common adverse effects in elderly subgroup. Alternately, non-elderly patients may be more prone to adverse effects such as infection, pharyngitis, somnolence, unpleasant taste and dry mouth. CONCLUSION: This meta-analysis showed that eszopiclone is an effective and safe therapy option for patients with primary insomnia, especially in elderly patients. However, due to the high clinical heterogeneity in some outcomes, further standardized preparation, large-scale and rigorously designed trials are needed.

The effects of a sleep/recovery supplement: 'Night Time Recharge' on sleep parameters in young adults.

BACKGROUND: Concentrated cherry juice reportedly contains melatonin which, in turn, has been highlighted as an important regulator in initiating sleep. AIM: The present investigation aims to clarify whether Night Time Recharge (NTR), a marketed sleep aid containing cherry extract, improves key sleep parameters in young, active adults with mildly poor sleep. METHODS: A double-blind, randomized, placebo-controlled, cross-over study design was employed. Twenty participants (nine female) consumed either NTR or a placebo for seven days. Accelerometers were used to assess sleep quality and physical activity levels. Urinary levels of 6-sulphatoxymelatonin (6-SMT), a marker of melatonin synthesis, was assessed via enzyme-linked immunosorbent assay. RESULTS: 6-SMT levels increased following NTR treatment (28.95 ng/ml) compared with placebo (4.0 ng/ml) (p < 0.001). There was also a significant difference (p = 0.047) in dietary tryptophan consumption during the NTR treatment (1236 mg) versus placebo (1149 mg). No trace of melatonin was detected from our analysis of the supplement. NTR had no significant effect on any sleep parameters with the exception of sleep latency (p = 0.001). CONCLUSIONS: As chemical analysis of NTR by liquid-chromatography mass-spectrometry identified no detectable melatonin, the tryptophan content of the supplement is a likely reason for improvement in sleep latency. These results are in contrast to previous studies which have found a positive effect on sleep following cherry supplementation. Future work should focus on sleep latency and investigating whether cherry juice is effective in participants with problems in initiating sleep.

Anti-inflammatory, anti-nociceptive and sedative-hypnotic activities of lucidone D extracted from Ganoderma lucidum.

Inflammation and insomnia are two types of symptoms very likely occur in life, seriously perplexing people's work and life. How to alleviate these symptoms is an urgent medical problem. Lucidone D (LUC) is a terpene from the ethanol extract of Ganoderma lucidum fruiting body. Triterpenoids are also the main pharmacological components of Ganoderma lucidum. In recent years, people pay more and more attention to its anti-inflammatory effect. In this study, LPS induced RAW264.7 macrophage inflammatory response model was used to evaluate the anti-inflammatory activity of LUC. The results showed that LUC could significantly inhibit the production of inflammatory mediators NO, which may play a role by down-regulating the expression level of iNOS and COX-2 proteins. Meanwhile, the production of TNF-α and IL-6 was significantly inhibited. These results indicate that LUC has obvious anti-inflammatory activity. Writhing and sedation tests in ICR male mice showed that LUC showed significant analgesic and sedative effects. In conclusion, these results suggest the anti-inflammatory, analgesic and sedative effects of LUC in vitro and in vivo.

GABA and l-theanine mixture decreases sleep latency and improves NREM sleep.

CONTEXT: γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter and it is well established that activation of GABAA receptors favours sleep. l-Theanine, a naturally occurring amino acid first discovered in green tea, is a well-known anti-anxiety supplement with proven relaxation benefits. OBJECTIVE: This study investigated the potential synergistic sleep enhancement effect of GABA/l-theanine mixture. MATERIALS AND METHODS: Pentobarbital-induced sleep test was applied to find proper concentration for sleep-promoting effect in ICR mice. Electroencephalogram (EEG) analysis was performed to investigate total sleeping time and sleep quality in normal SD rats and caffeine-induced awareness model. Real-time polymerase chain reaction (RT-PCR) was applied to investigate whether the sleep-promoting mechanism of GABA/l-theanine mixture involved transcriptional processes. RESULTS: GABA/l-theanine mixture (100/20 mg/kg) showed a decrease in sleep latency (20.7 and 14.9%) and an increase in sleep duration (87.3 and 26.8%) compared to GABA or theanine alone. GABA/l-theanine mixture led to a significant increase in rapid eye movement (REM) (99.6%) and non-REM (NREM) (20.6%) compared to controls. The use of GABA/l-theanine mixture rather than GABA or l-theanine alone restored to normal levels sleep time and quality in the arousal animal model. The administration of GABA/l-theanine led to increased expression of GABA and the glutamate GluN1 receptor subunit. CONCLUSIONS: GABA/l-theanine mixture has a positive synergistic effect on sleep quality and duration as compared to the GABA or l-theanine alone. The increase in GABA receptor and GluN1 expression is attributed to the potential neuromodulatory properties of GABA/l-theanine combination, which seems to affect sleep behaviour.

Suvorexant (Belsomra® Tablets 10, 15, and 20 mg): Japanese Drug-Use Results Survey.

BACKGROUND: We report on the results of a Japanese postmarketing drug-use survey of suvorexant (Belsomra®) tablets. METHODS: A survey with a ≤ 6-month observation period after the start of administration was conducted, targeting insomnia patients who were treated with suvorexant for the first time in Japan. Information on the safety and efficacy of the drug product was collected. The evaluation period was July 21, 2015-August 12, 2017, and the target number of patients was 3428. RESULTS: The mean administration period for the safety analysis population of 3248 patients was 113 days. At 6 months after the start of treatment, 48.6% (1577/3248) of the patients had been continually receiving treatment, and 51.4% (1671/3248) of the patients discontinued/dropped out of treatment before 6 months. Among the patients who discontinued/dropped out of the treatment, more than 30% discontinued due to improvement. The mean treatment duration for those who had discontinued treatment for this reason was 62 days. The incidence rate of adverse drug reactions among those in the safety analysis population was 9.7%, and the common adverse drug reactions were somnolence (3.6%), insomnia (1.2%), dizziness (1.1%), and nightmare (0.8%), all of which are described in the product label. No additional noteworthy events were observed. In 2439 patients with a final overall global assessment of sleep judged by physicians, the 'improved' rate was 74.0%. Among 2424 patients who provided a final overall global assessment, the improvement rate was 73.2%, which was comparable with the improvement rate judged by physicians. Regarding clinical effects (based on patient diary data or physician's assessment), reduction in median sleep latency and increase in median total sleep time (reduction from 60 to 50 min and increase from 300 to 360 min compared with baseline, respectively) were observed at 1 week after the start of treatment and onwards, and the effect was maintained after the start of treatment for 6 months. A similar effect was observed irrespective of age groups or reasons for using suvorexant. CONCLUSION: This survey was an exploratory observational study without a control group; the interpretation of results may require the consideration of factors that may have caused bias in the results, such as demographic characteristics and effects of other drugs. However, the results suggest that suvorexant can be a useful drug in daily clinical practice for treating insomnia.

[Melatonin for children with insomnia].

Treatment for insomnia with melatonin (MT) in children and adolescents aged 0-17 years has doubled since 2011. The efficacy and safety profile for MT in children has not been determined. Recent clinical trials indicate, that MT only has a clinical effect on sleep latency, not on total sleep time. Furthermore, it has emerged, that proper sleep hygiene can cure the sleep problem in 50% of the children. Typically, the safety evaluation only entails an unclassified report of adverse events. Two long-term studies investigate and dispel the potential influence of MT on puberty.

Triphlorethol A, a Dietary Polyphenol from Seaweed, Decreases Sleep Latency and Increases Non-Rapid Eye Movement Sleep in Mice.

In our previous studies, we have demonstrated that marine polyphenol phlorotannins promote sleep through the benzodiazepine site of the gamma-aminobutyric acid type A (GABAA) receptors. In this follow-up study, the sleep-promoting effects of triphlorethol A, one of the major phlorotannin constituents, were investigated. The effect of triphlorethol A on sleep-wake architecture and profiles was evaluated based on electroencephalogram and electromyogram data from C57BL/6N mice and compared with the well-known hypnotic drug zolpidem. Oral administration of triphlorethol A (5, 10, 25, and 50 mg/kg) dose-dependently decreased sleep latency and increased sleep duration during pentobarbital-induced sleep in imprinting control region mice. Triphlorethol A (50 mg/kg) significantly decreased sleep latency and increased the amount of non-rapid eye movement sleep (NREMS) in C57BL/6N mice, without affecting rapid eye movement sleep (REMS). There was no significant difference between the effects of triphlorethol A at 50 mg/kg and zolpidem at 10 mg/kg. Triphlorethol A had no effect on delta activity (0.5⁻4 Hz) of NREMS, whereas zolpidem significantly decreased it. These results not only support the sleep-promoting effects of marine polyphenol phlorotannins, but also suggest that the marine polyphenol compound triphlorethol A is a promising structure for developing novel sedative hypnotics.

Non-24-Hour Sleep-Wake Circadian Rhythm Disorder in a Sighted Male With Normal Functioning.

ABSTRACT: This is a rare case of non-24-hour sleep-wake rhythm disorder in a sighted male with normal functioning. The patient, a 23-year-old doctorate graduate student, presented with difficulty falling asleep and excessive daytime sleepiness. He reported variable sleep and wake times. Overnight baseline polysomnography was unremarkable and his Multiple Sleep Latency Test was significant for short mean sleep latency. Sleep diary and actigraphy were obtained, which demonstrated a pattern of delaying of sleep and wake times each day. He had excellent symptom response to nightly melatonin.

Adenosine A2A receptor mediates hypnotic effects of ethanol in mice.

Ethanol has extensive effects on sleep and daytime alertness, causing premature disability and death. Adenosine, as a potent sleep-promoting substance, is involved in many cellular and behavioral responses to ethanol. However, the mechanisms of hypnotic effects of ethanol remain unclear. In this study, we investigated the role of adenosine in ethanol-induced sleep using C57BL/6Slac mice, adenosine A2A receptor (A2AR) knockout mice, and their wild-type littermates. The results showed that intraperitoneal injection of ethanol (3.0 g/kg) at 21:00 decreased the latency to non-rapid eye movement (NREM) sleep and increased the duration of NREM sleep for 5 h. Ethanol dose-dependently increased NREM sleep, which was consistent with decreases in wakefulness in C57BL/6Slac mice compared with their own control. Caffeine (5, 10, or 15 mg/kg), a nonspecific adenosine receptor antagonist, dose-dependently and at high doses completely blocked ethanol-induced NREM sleep when administered 30 min prior to (but not after) ethanol injection. Moreover, ethanol-induced NREM sleep was completely abolished in A2AR knockout mice compared with wild-type mice. These findings strongly indicate that A2AR is a key receptor for the hypnotic effects of ethanol, and pretreatment of caffeine might be a strategy to counter the hypnotic effects of ethanol.