• Biomolecules & Therapeutics
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• v.24 no.2
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• pp.115-122
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• 2016

Sleep, which is an essential part of human life, is modulated by neurotransmitter systems, including gamma-aminobutyric acid (GABA) and dopamine signaling. However, the mechanisms that initiate and maintain sleep remain obscure. In this study, we investigated the relationship between melatonin (MT) and dopamine D2-like receptor signaling in pentobarbital-induced sleep and the intracellular mechanisms of sleep maintenance in the cerebral cortex. In mice, pentobarbital-induced sleep was augmented by intraperitoneal administration of 30 mg/kg MT. To investigate the relationship between MT and D2-like receptors, we administered quinpirole, a D2-like receptor agonist, to MT- and pentobarbital-treated mice. Quinpirole (1 mg/kg, i.p.) increased the duration of MT-augmented sleep in mice. In addition, locomotor activity analysis showed that neither MT nor quinpirole produced sedative effects when administered alone. In order to understand the mechanisms underlying quinpirole-augmented sleep, we measured protein levels of mitogen-activated protein kinases (MAPKs) and cortical protein kinases related to MT signaling. Treatment with quinpirole or MT activated extracellular-signal-regulated kinase 1 and 2 (ERK1/2), p38 MAPK, and protein kinase C (PKC) in the cerebral cortex, while protein kinase A (PKA) activation was not altered significantly. Taken together, our results show that quinpirole increases the duration of MT-augmented sleep through ERK1/2, p38 MAPK, and PKC signaling. These findings suggest that modulation of D2-like receptors might enhance the effect of MT on sleep.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.27-36
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• 2017

Angelicae Gigantis Radix (AGR, Angelica gigas) has been used for a long time as a traditional folk medicine in Korea and oriental countries. Decursinol angelate (DCA) is structurally isomeric decursin, one of the major components of AGR. This study was performed to confirm whether DCA augments pentobarbital-induced sleeping behaviors via the activation of $GABA_A$-ergic systems in animals. Oral administration of DCA (10, 25 and 50 mg/kg) markedly suppressed spontaneous locomotor activity. DCA also prolonged sleeping time, and decreased the sleep latency by pentobarbital (42 mg/kg), in a dose-dependent manner, similar to muscimol, both at the hypnotic (42 mg/kg) and sub-hypnotic (28 mg/kg) dosages. Especially, DCA increased the number of sleeping animals in the sub-hypnotic dosage. DCA (50 mg/kg, p.o.) itself modulated sleep architectures; DCA reduced the counts of sleep/wake cycles. At the same time, DCA increased total sleep time, but not non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. In the molecular experiments. DCA (0.001, 0.01 and $0.1{\mu}g/ml$) increased intracellular Cl- influx level in hypothalamic primary cultured neuronal cells of rats. In addition, DCA increased the protein expression of glutamic acid decarboxylase ($GAD_{65/67}$) and $GABA_A$ receptors subtypes. Taken together, these results suggest that DCA potentiates pentobarbital-induced sleeping behaviors through the activation of $GABA_A$-ergic systems, and can be useful in the treatment of insomnia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.6
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• pp.996-999
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• 2011

This experiment was performed to investigate whether the combined-preparation of crude drugs (The $Well^{TM}$ Preparation, TW), has hypnotic effects and/or enhances pentobarbital-induced sleep behaviors. TW was mixed with water extracts of Ginseng Radix red, Germinated brown rice, cultured mountain ginseng, and 50% ethanol extracts of Longanae Arillus, Nelumbinis Folium and Chrysanthemi Flos. TW (100 mg/kg, p.o.) reduced sleep onset and prolonged sleep time induced by pentobarbital similar to muscimol (0.2 ${\mu}M$), a $GABA_A$ receptor agonist. Also, TW (2 ${\mu}g$/ml) and pentobarbital (2.5 ${\mu}M$) did not affect the chloride influx in primary cultured cerebellar granule cells, respectively, but the combined-treatment of TW (2 ${\mu}g$/ml) and pentobarbital (2.5 ${\mu}M$) increased the chloride influx onto the cells. In conclusion, TW augments pentobarbital-induced sleep behaviors; these effects may result from chloride channel activation.

• The Korean Journal of Pharmacology
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• v.15 no.1_2 s.25
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• pp.13-19
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• 1979

Circadian susceptibility of sleeping induced by pentobarbital was observrd in male DDO mouse treated with phenobarbital and ginseng saponin. The pentobarbital elimination rate was also measured in the same animal. The mouse had been maintained for one week under 12 hours of artificial illumination extending from 06:00 to 18:00 hours alternating with 12 hours of darkness. During the period the animals were administered intraperitoneally with 100mg/kg of phenobarbital for three days or 10mg/kg and 100mg/kg of ginseng saponin for seven days. At 24 hours after last injection pentobarbital sleeping time and elimination rate were measured following intraperitoneal administration of 50mg/kg of pentobarbital sodium. In a control group treated with saline, the duration of pentobarbital-induced sleep varied with circadian rhythmicity, which had a trough at 02:00 hours of light phase and a crest at 14:00 hours of dark phase. And the elimination rate measured at 02:00 hours was faster than that at 14:00 hours. Pretreatment with phenobarbital markedly shortened the pentobarbital steeping time and abolished the circadian rhythmicity. Those were correlated with the increased pentobartital elimination by phenobarbital throughout light and dark phases examined. Ginseng saponin, given for seven days in a dose of 10mg/kg or 100mg/kg, did not affect the circadian rhythmicity of sleeping and the elimination rate. Sleeping time during light phase, however, was somewhat shortened in ginseng treated animals, which was not matched with the finding of unaltered elimination rate. It seemed that the central nervous system stimulating effect of ginseng saponin might be involved in the findings observed.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.479-485
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• 2015

This study was performed to investigate the sedative-hypnotic activity of ${\gamma}$-aminobutyric acid (GABA)-enriched fermented marine organisms (FMO), including sea tangle (FST) and oyster (FO) by Lactobacillus brevis BJ20 (L. brevis BJ20). FST and FO were tested for their binding activity of the $GABA_A$-benzodiazepine and 5-$HT_{2C}$ receptors, which are well-known molecular targets for sleep aids. We also measured the sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of FST and FO. In $GABA_A$ and 5-$HT_{2C}$ receptor binding assays, FST displayed an effective concentration-dependent binding affinity to $GABA_A$ receptor, similar to the binding affinity to 5-$HT_{2C}$ receptor. FO exhibited higher affinity to 5-$HT_{2C}$ receptor, compared with the $GABA_A$ receptor. The oral administration of FST and FO produced a dose-dependent decrease in sleep latency and increase in sleep duration in pentobarbital-induced hypnosis. The data demonstrate that FST and FO possess sedativehypnotic activity possibly by modulating $GABA_A$ and 5-$HT_{2C}$ receptors. We propose that FST and FO might be effective agents for treatment of insomnia.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.314-320
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• 2014

This study was investigated to know whether pachymic acid (PA), one of the predominant triterpenoids in Poria cocos (Hoelen) has the sedative-hypnotic effects, and underlying mechanisms are mediated via ${\gamma}$-aminobutyric acid (GABA)-ergic systems. Oral administration of PA markedly suppressed locomotion activity in mice. This compound also prolonged sleeping time, and reduced sleep latency showing synergic effects with muscimol (0.2 mg/kg) in shortening sleep onset and enhancing sleep time induced by pentobarbital, both at the hypnotic (40 mg/kg) and sub-hypnotic (28 mg/kg) doses. Additionally, PA elevated intracellular chloride levels in hypothalamic primary cultured neuronal cells of rats. Moreover, Western blotting quantitative results showed that PA increased the amount of protein level expression of $GAD_{65/67}$ over a broader range of doses. PA increased ${\alpha}$- and ${\beta}$-subunits protein levels, but decreased ${\gamma}$-subunit protein levels in $GABA_A$ receptors. The present experiment provides evidence for the hypnotic effects as PA enhanced pentobarbital-induced sleeping behaviors via $GABA_A$-ergic mechanisms in rodents. Taken together, it is proposed that PA may be useful for the treatment of sleep disturbed subjects with insomnia.

• Biomolecules & Therapeutics
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• v.32 no.5
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• pp.531-539
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• 2024

Sleep is one of the most essential physiological phenomena for maintaining health. Sleep disturbances, such as insomnia, are often accompanied by psychiatric or physical conditions such as impaired attention, anxiety, and stress. Medication used to treat insomnia have concerns about potential side effects with long-term use, so interest in the use of alternative medicine is increasing. In this study, we investigated the hypnotic effects of β-lapachone (β-Lap), a natural naphthoquinone compound, using pentobarbital-induced sleep test, immunohistochemistry, real-time PCR, and western blot in mice. Our results indicated that β-Lap exerts a significant hypnotic effect by showing a decrease in sleep onset latency and an increase in total sleep time in pentobarbital-induced sleep model. The results of c-Fos immunostaining showed that β-Lap decreased neuronal activity in the basal forebrain and lateral hypothalamus, which are wakefulness-promoting brain regions, while increasing in the ventrolateral preoptic nucleus, a sleep-promoting region; all these effects were significantly abolished by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an adenosine A₁ receptor (A₁R) antagonist. Western blot analysis showed that β-Lap increased extracellular signal-regulated kinase phosphorylation and nuclear factor-kappa B translocation from the cytoplasm to the nucleus; these effects were inhibited by DPCPX. Additionally, β-Lap increased the mRNA levels of A₁R. Taken together, these results suggest that β-Lap exerts hypnotic effects, potentially through A₁R.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.646-653
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• 2017

Alcalase hydrolysis of liquid egg white was used to produce 5-hydroxytryptophan (HTP) under various conditions and investigate the sleep-potentiating activity of liquid egg white hydrolysate (LEH) on pentobarbital-induced sleep. Alcalase hydrolysis yielded the highest content of 5-HTP ($13.50{\mu}g/mL$), while neutrase hydrolysis showed the lowest 5-HTP content ($5.23{\mu}g/mL$). The liquid egg white to water ratio (1:1) was optimal for the production of 5-HTP with high amino-nitrogen (A-N) content and degree of hydrolysis. The 5-HTP, amino-nitrogen, and degree of hydrolysis increased until 24 h of hydrolysis and slightly increased thereafter during hydrolysis with 2% and 5% enzyme addition. 5-HTP administration at doses of 6 and 9 mg/kg significantly increased sleep duration and decreased sleep latency time compared to that in the control (p<0.05). LEH (150 mg/mouse), which was equivalent to 5-HTP at 6 mg/kg, significantly decreased sleep latency time and increased sleep duration time compared to that in the control (p<0.05). Oral administration of LEH showed sleep-potentiating effects because of 5-HTP. The sleep-potentiating activity of LEH may have occurred through 5-HTP in our pentobarbital-induced sleep model. LEH may be a valuable alternative to sleep enhancement and may be used as a sleep-potentiating agent.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.208-214
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• 2018

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate the biological and sleep-promoting effects of combined ${\gamma}$-aminobutyric acid (GABA) and 5-hydroxytryptophan (5-HTP) using caffeine-induced sleepless fruit flies, ICR mice, and Sprague-Dawley rats. MATERIALS/METHODS: Video-tracking analysis was applied to investigate behavioral changes of Drosophila melanogaster. Pentobarbital-induced sleep test and electroencephalogram (EEG) patterns were used for analysis of sleep latency, duration, and quantity and quality of sleep in vertebrate models. RESULTS: Administration of combined GABA/5-HTP could significantly reverse the caffeine induced total distance of flies (P < 0.001). Also, individually administered and combined GABA/5-HTP significantly increased the total sleeping time in the caffeine-induced sleepless ICR mice (P < 0.001). In the caffeine-induced sleepless SD-rats, combined GABA/5-HTP showed significant differences in sleep quality between individual amino acid administrations (P < 0.05). CONCLUSIONS: Taken together, we identified inhibitory effects of combined GABA/5-HTP in locomotor activity, sleep quantity and quality in caffeine-induced sleepless models, indicating that combined GABA/5-HTP may be effective in patients with insomnia by providing sufficient sleep.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.432-438
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• 2018

Worldwide, caffeine is among the most commonly used stimulatory substances. Unfortunately, significant caffeine consumption is associated with several adverse effects, ranging from sleep disturbances (including insomnia) to cardiovascular problems. This study investigates whether treatment with the Evodia rutaecarpa aqueous extract (ERAE) from berries and its major molecular component, evodiamine, can reduce the adverse caffeine-induced sleep-related and excitation effects. We combined measurements from the pentobarbital-induced sleep test, the open field test, and the locomotor activity test in mice that had been dosed with caffeine. We found that ERAE and evodiamine administration reduced the degree of caffeine-induced sleep disruption during the sleep test. Additionally, we found that evodiamine significantly inhibits caffeine-induced excitation during the open field test, as well as decreasing hyperlocomotion in the locomotor activity test. Additional in vitro experiments showed that caffeine administration decreased the expression of ${\gamma}$-aminobutyric acid $(GABA)_A$ receptor subunits in the mouse hypothalamus. However, evodiamine treatment significantly reversed this expression reduction. Taken together, our results demonstrate that ERAE and its major compound, evodiamine, provide an excellent candidate for the treatment or prevention of caffeine-induced sleep disturbances and excitatory states, and that the mechanism of these beneficial effects acts, at least in part, through the $GABA_A$-ergic system.