• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.598-601
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• 2010

This experiment was performed to investigate whether the combined-preparation of water extracts of germinated brown rice (WGR), water extracts of cultured mountain ginseng (WCG) and 70% ethanol extracts of Longanae Arillus (ELA) has hypnotic effects and/or enhances pentobarbital-induced sleep behaviors through the GABAergic system. The combined-preparation of WGR and WCG reduced sleep latency and prolonged sleep time induced by pentobarbital. ELA also reduced sleep latency and prolonged sleep time induced by pentobarbital. However, WGR or WCG itself did not induce sleep. The combined-preparation of WGR, WCG and ELA strongly reduced sleep latency and prolonged sleep time via chloride influx into primary cultured cerebellar granule cells. In conclusion, the combined-preparation of WGR, WCG and ELA augments pentobarbital-induced sleep behaviors through the modification of GABAergic system.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.508-516
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• 2007

Thymus magnus is an endemic (Ulleung Island) species in Korea. This plant is used as diaphoretics and carminatives in traditional medicine. In the literature, few scientific assays were realized on this species, such as antibiotic (Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and S. typhimurium) and antifungal activities. In order to clarify whether essential oil of T. magnus have pharmacological effects, anti-inflammatory, sedative, anti-depressant, analgesic, and sleep-prolonged effects were investigated using animal models. From this study, the following conclusions were attained; 1) Essential oil of T. magnus did not show any acute toxicity on mice when orally administered at the dose of 2-3 g/kg body weight. 2) Essential oil of T. magnus possessed strong anti-inflammatory activity, similar to that of a positive control prednisolone. 3) Essential oil of T. magnus had excellent analgesic activity, comparable to that of aspirin. 4) The essential oil of T. magnus possessed strong sleep-prolonged effect on pentobarbital induced-sleep test in mice model. 5) In the hot plate test, the essential oil of T. magnus had moderate effect. 6) And the essential oil of T. magnus had no significant effects in forced-swimming test and open-field test.

• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.149-154
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• 2023

Objectives : Far-infrared (FIR) lights have been investigated for sleep quality intervention. We sought to measure the advantageous effects of FIR in sleep using polysomnographic data as the objective outcomes. Methods : The ten healthy volunteers were enrolled in a single-center, prospective, patient-blind, single-arm trial. Individuals slept on a sham mattress and a FIR emitting mattress with polysomnography for one night each. Results : Sleep efficiency showed an increasing trend but was not statistically significant. PSQI-K significantly decreased (p=0.013). The latency to REM of the baseline was shorter than that of the intervention (p=0.008). Though there was no statistical significance, Stage N1 and N2 were shortened, and Stage N3 was prolonged after the intervention compared to the baseline. Conclusions : The FIR-emitting mattresses improved sleep quality on self-reported insomnia. We suggested the candidate for the markers altered by the FIR therapy, such as the normalization of REM latency and increased N3 sleep.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1364-1369
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• 2017

There is a growing demand for natural sleep aids due to various side effects of long-term administration of pharmacological treatments for insomnia. Honey has been reported to exhibit numerous potential health benefits, and it is hypothesized that honey may favorably affect insomnia treatment. Therefore, this study was performed to investigate the possible hypnotic effect of clover honey (CH) and to determine its in vivo mechanism. The total flavonoid content (TFC) of CH and fractions extracted with ethylacetate (EtOAc) and $H_2O$ was measured. The pentobarbital-induced sleep test using $GABA_A$-benzodiazepine (BZD) agonists and antagonists was conducted to evaluate the potential mechanism of action behind the sedative-hypnotic activity of CH in mice. The results showed that administration of 500 and 1,000 mg/kg of CH significantly (p<0.01) reduced the sleep latency to a level similar to that of diazepam (DZP, 2 mg/kg), and 1,000 mg/kg of CH significantly (p<0.01) prolonged the sleep duration, which was comparable to that of DZP (2 mg/kg). Administration of the EtOAc fraction with a higher TFC significantly reduced the sleep latency at 50 to 200 mg/kg and prolonged the sleep duration at 100 to 200 mg/kg, which were comparable to those after administration of DZP (2 mg/kg). However, co-administration of CH and EtOAc with flumazenil, a specific $GABA_A-BZD$ receptor antagonist, blocked the hypnotic effect. Our findings suggest that the hypnotic activity of CH may be attributed to allosteric modulation of $GABA_A-BZD$ receptors. The TFC of CH is expected to be a key factor that contributes to its hypnotic effect.

• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.1-6
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• 2021

[Purpose] We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [Methods] Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% ${\dot{V}}O_{2max}$) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00-7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% ${\dot{V}}O_{2max}$), and time to exhaustion (TTE) at 85% ${\dot{V}}O_{2max}$ were evaluated. [Results] On day 2, neither the MVC nor ${\dot{V}}O_2$ during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [Conclusion] A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.108-112
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• 2003

Objectives: The purpose of this study is to investigate the psychophysiological effects of total sleep deprivation by using auditory event-related potentials. Methods: Twenty four healthy college students (18 men, 6 women) participated in this study. The subjects remained awake for 37 hours under continuous surveillance. In the morning and the evening of two consecutive study days, auditory event-related potentials were checked. Results: The latencies of P300 and N200 were significantly prolonged (p<0.001) and their amplitudes decreased (p<0.05) as a consequence of sleep deprivation. The amplitude of P200 was significantly increased during sleep deprivation (p<0.05). However, there was no significant change in the latency and amplitude of N100. Conclusion: Among the components of auditory event-related potentials, P300 and N200 are good indicators of sleep-deprived status. Further investigation is necessary to elucidate the neurophysiological mechanisms of these findings.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.2
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• pp.59-63
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• 2012

Melatonin has been studied as a potential treatment of cancer, immune disorders, cardiovascular diseases, depression, seasonal affective disorder (SAD), circadian rhythm sleep disorders, sexual dysfunction and some forms of insomnia. Prolonged release melatonin has shown good results in treating insomnia in older adults. It may ameliorate circadian misalignment and SAD. Basic research indicates that melatonin may play a significant role in modulating the effects of drugs of abuse such as cocaine. A 2004 review found that melatonin significantly increased total sleep time in people suffering from sleep restriction. Therefore, in this study, in order to explain characteristics of melatonin, total energy, net charge, vibrational mode of melatonin are calculated by PM3 methods of HyperCam 6.0.

• 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.

• Safety and Health at Work
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• v.7 no.4
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• pp.363-371
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• 2016

Background: Seafaring is an inherently stressful environment. Because working time and leisure time is spent in the same confined environment for a prolonged period of time, many stressors present in seafaring can also be conceived of as chronic. We explored the effects of duration at sea, seafaring experience, environmental stressors, and psychological capital (PsyCap) on the sleep quality and fatigue of seafarers. PsyCap is a construct that draws upon ideas from positive psychology and positive organizational behavior, and is intended to capture an individual's psychological capacities that can be developed and utilized for performance improvements. Methods: We collected survey data from a sample of seafarers working in the offshore re-supply industry (n = 402) and a sample of seafarers working on board combined passenger and cargo ships (n = 340). Results: PsyCap emerged as a robust predictor with statistically significant relations to fatigue and sleep quality in both samples. PsyCap also interacted with duration at sea in explaining fatigue in seafarers working on board the passenger and cargo ships. Seafarers on passenger and cargo ships also reported significantly higher levels of fatigue than those working in the offshore re-supply industry. Conclusion: Coupled with emerging research showing that PsyCap is trainable, our results suggest that maritime organizations could have much to gain by being cognizant of and developing routines for continually developing the PsyCap of their employees.

• Natural Product Sciences
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• v.21 no.3
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• pp.219-225
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• 2015

In the previous experiments, we reported that ethanol extract of Gastrodiae Rhizoma, the dried tuber of Gastrodia ElataBlume (Orchidaceae) increased pentobarbital-induced sleeping behaviors. These experiments were undertaken to know whether 4-hydroxybenzaldehyde (4-HBD), is one of the major compounds of Gastrodiae Rhizoma increases pentobarbital-induced sleeping behaviors and changes sleep architectures via activating GABA_A-ergic systems in rodents. 4-HBD decreased locomotor activity in mice. 4-HBD increased total sleep time, and decreased of sleep onset by pentobarbital (28 mg/kg and 40 mg/kg). 4-HBD showed synergistic effects with muscimol (a GABA_A receptor agonist), shortening sleep onset and enhancing sleep time on pentobarbital-induced sleeping behaviors. On the other hand, 4-HBD (200 mg/kg, p.o.) itself significantly inhibited the counts of sleepwake cycles, and prolonged total sleep time and non-rapid eye movement (NREM) in rats. Moreover, 4-HBD increased intracellular Cl⁻ levels in the primary cultured cerebellar cells. The protein levels of glutamic acid decarboxylase (GAD) and GABA_A receptors subunits were over-expressed by 4-HBD. Consequently, these results demonstrate that 4-HBD increased NREM sleep as well as sleeping behaviors via the activation of GABA_A-ergic systems in rodents.