• 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.

• Archives of Pharmacal Research
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• v.28 no.8
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• pp.930-935
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• 2005

We have investigated the effects of relatively high concentration of carbachol (CCh), an agonist of muscarinic acetylcholine receptor (mAChR), on cardiac automaticity in mouse heart. Action potentials from automatically beating right atria of mice were measured with conventional microelectrodes. When atria were treated with $100{\mu}M$ CCh, atrial beating was immediately arrested and diastolic membrane potential (DMP) was depolarized. After exposure of the atria to CCh for $\~4 min$, action potentials were regenerated. The regenerated action potentials had lower frequency and shorter duration when compared with the control. When atria were pre-exposed to pirenzepine $(1{\mu}M)$, an $M_1$ mAChR antagonist, there was complete inhibition of CCh-induced depolarization of DMP and regeneration of action potentials. Pre-exposure to AFDX-116 (11 ({2-[(diethylamino)-methyl]-1-piperidyl}acetyl)-5, 11-dihydro-6H-pyridol[2,3-b][1,4] benzodiazepine-6-one base, $1{\mu}M$), an $M_2$ mAChR antagonist, failed to block CCh-induced arrest of the beating. However, prolonged exposure to CCh elicited gradual depolarization of DMP and slight acceleration in beating rate. Our data indicate that high concentration of CCh depolarizes membrane potential and recovers right atrial automaticity via $M_1$ mAChR, providing functional evidence for the role of $M_1$ mAChR in the atrial myocytes.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.314-322
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• 1994

This study aimed to investigate the existence of GABA receptor and the mechanisms of action of GABA and diazepam on the trachealis muscle isolated from dog. Horizontal muscle strips of $2mm{\times}15mm$ were prepared from canine trachea, and isometric myography in isolated muscle chamber bubbled with 95/5%-$O_2/CO_2$at $36^{\circ}C$, at the pH of 7.4 was performed. Muscle strips contracted responding to the electrical field stimulation (ESP) by 2~20 Hz, 20 msec, monophasic square wave of 60 VDC GABA and diazepam suppressed the EFS-induced contractions to the similar extent, significantly. (p<0.05) Bicuculline, a $GABA_A$ receptor antagonist blocked both GABA- and diazepam- inhibitions; but DAVA, a $GABA_B$ receptor antagonist did not affect either of them. These results suggest that in the canine trachealis muscle, there may be only $GABA_A$ receptor, and GABA and diazepam inhibit the contractility via $GABA_A$A receptor.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.189-195
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• 1988

This study aimed to investigate the autonomic innervations of human vas deferens and the effect of diazepam, a benzodiazepine sedative antianxiety drug, on the smooth muscle contractility of vas deferens. The specimens were obtained from healthy volunteers undergoing elective vasectomy with local anesthesia. The muscle preparation did not show any spontaneous contraction, but showed a good contraction induced by norepinephrine exerting the strongest response at $33^{\circ}C$. Phentolamine inhibited the norepinephrine-induced contraction concentration-dependently. Isoproterenol, a beta-adrenergic agonist evoked a considerable extent of contraction, and this contractile activity was antagonized by propranolol, a beta-adrenergic blocking agent. Acetylcholine induced a dashing contraction of the human vas deferens, and atropine, a muscarinic receptor blocking agent abolished the acetylcholine-induced contraction. Diazepam inhibited the norepinephrine-induced contraction in a concentration dependent manner. These results suggest that the smooth muscle of human vas deferens has cholinergic muscarinic and beta adrenergic receptors as well as the predominant alpha adrepergic receptor. Diazepam inhibits the motility, especially norepinephrine-induced contraction of human vas deferens.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.119-142
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• 2008

Zizyphi Spinosi Semen (ZSS) has been widely used for the treatment of anxiety and insomnia in Korea and China. This experiment was performed to know whether sanjoinine A, one of major alkaloid compounds of ZSS has anxiolytic and hypnotic effects through the GABAergic systems. Our results showed that administration of sanjoinine A increased open arm entries and spent time in open arm in the elevated plus-maze and increased head dips in hole board test. Different from traditional anxiolytic, diazepam, sanjoinine A itself did not decrease locomotor activity and strength level in mice. Furthermore, Sanjoinine A (0.5-2.0 mg/kg) prolonged sleeping time and reduced sleeping latency induced by pentobarbital in a dose-dependent manner similar to muscimol, a $GABA_A$ receptor agonist. Sanjoinine A (0.25-1.0 mg/kg) also increased sleeping rate and sleeping time in the combined administration at the sub-hypnotic dose of pentobarbital and showed synergic effects with muscimol in potentiating sleeping onset and enhancing sleeping time induced by pentobarbital. However, sanjoinine A itself did not induce sleeping at the higher dose. In addition, both of sanjoinine A and pentobarbital increased chloride influx in primary cultured cerebellar granule cells. Sanjoinine A decreased the $GABA_A$ receptor ${\alpha}$-subunit expression and increased ${\gamma}$-subunit expression, and had no effects on abundance of ${\beta}$-subunit in primary cultured cerebellar granule cells, showing different expression of subunits from pentobarbital. In conclusion, sanjoinine A shows anxiolytic-like effects and augments pentabarbital-induced sleeping behaviors through the modification of GABAergic systems. [This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (The Regional Research Universities Program/Center for Healthcare Technology Development)].

• Journal of Oriental Neuropsychiatry
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• v.19 no.1
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• pp.43-54
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• 2008

Objective: The aim of this study is to evaluate the anticonvulsive effects of Gamiheichumhwan extract and to explain its action in GABAergic neuromodulation of the rat brain. Method: The extracts of Gamiheichumhwan were investigated for their inhibitory effect on GABA transaminase activity, their influence on brain GABA and glutamate levels, their agonistic activity on GABA/benzodiazepine receptor and anticonvulsive action using in vitro and in vivo assays. Results: 1. The extract inhibited dose-dependently GABA transaminase (GABA-T) activity by 4.6% and 18.9%, respectively at dosages of 250 mg/kg and 500mg/kg mouse (p.o.). 2. Brian GABA level was increased to 72.0% and brain glutamate level was decreased to 9.6% at a dosage of 500 mg/kg mouse (p.o.). 3. The extract suppressed [3H]Ro15-1788 binding to rat cerebral cortical membrane by $81.4{\pm}0.8%$ at a dosage of 3.2 mg, suggesting its agonistic activity on GABA/benzodiazepin receptor. 4. The extract showed anticonvulsive effect by lengthening the onset time of convulsion, shortening the convulsion duration and diminishing the lethality. Conclusion : It is suggested that Gamiheichumhwan can be used to somnipathy and adapted to treatment and prevention of epilepsy or convulsion.

• BMB Reports
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• v.53 no.1
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• pp.20-27
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• 2020

Translocator protein (TSPO), also known as peripheral benzodiazepine receptor, is a transmembrane protein located on the outer mitochondria membrane (OMM) and mainly expressed in glial cells in the brain. Because of the close correlation of its expression level with neuropathology and therapeutic efficacies of several TSPO binding ligands under many neurological conditions, TSPO has been regarded as both biomarker and therapeutic target, and the biological functions of TSPO have been a major research focus. However, recent genetic studies with animal and cellular models revealed unexpected results contrary to the anticipated biological importance of TSPO and cast doubt on the action modes of the TSPO-binding drugs. In this review, we summarize recent controversial findings on the discrepancy between pharmacological and genetic studies of TSPO and suggest some future direction to understand this old and mysterious protein.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.217-221
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• 2007

Ginseng has been widely used for the management of anxiety and emotional instability, but there is little experimental evidence supporting these clinical applications. The anxiolytic-like effect of ginseng saponin and polysaccharide fractions of white (WG) and red ginsengs (RG) was investigated using the elevated plus-maze test. The saponin (SF) and polysaccharide (PF) fractions were orally administered to male ICR mice for 3 days and behavioral test for the anxiolytic activity were performed. SF significantly increased the time-spent open arms and number into the in the open arm entries. However, PF weakly increased the time-spent in the open arms, but did not increase number into the open ann entries. The WG showed more potent anxiolytic-like effect than that of RG. The anxiolytic-like activities were antagonized by flumazenil, but not by esmolol. These findings suggest the saponin fractions of WG and RG promote the anxiolytic-like activity by antagonizing GABN/benzodiazepine receptors in mice.

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.3-19
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• 2001

Recent basic and clinical studies demonstrate a major role for neural plasticity in the etiology and treatment of depression and stress-related illness. The neural plasticity is reflected both in the birth of new cell in the adult brain(neurogenesis) and the death of genetically healthy cells(apoptosis) in the response to the individual's interaction with the environment. The neural plasticity includes adaptations of intracellular signal transduction pathway and gene expression, as well as alterations in neuronal morphology and cell survival. At the cellular level, repeated stress causes shortening and debranching of dendrite in the CA3 region of hippocampus and suppress neurogenesis of dentate gyrus granule neurons. At the molecular level, both form of structural remodeling appear to be mediated by glucocorticoid hormone working in concert with glutamate and N-methyl-D-aspartate(NMDA) receptor, along with transmitters such as serotonin and GABA-benzodiazepine system. In addition, the decreased expression and reduced level of brain-derived neurotrophic factor(BDNF) could contribute the atrophy and decreased function of stress-vulnerable hippocampal neurons. It is also suggested that atrophy and death of neurons in the hippocampus, as well as prefrontal cortex and possibly other regions, could contribute to the pathophysiology of depression. Antidepressant treatment could oppose these adverse cellular effects, which may be regarded as a loss of neural plasticity, by blocking or reversing the atrophy of hippocampal neurons and by increasing cell survival and function via up-regulation of cyclic adenosine monophosphate response element-binding proteins(CREB) and BDNF. In this article, the molecular and cellular mechanisms that underlie stress, depression, and action of antidepressant are precisely discussed.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.139-143
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• 2005

Periodic limb movements in sleep (PLMS) have been diagnosed easily by nocturnal polysomnography (NPSG) and treated effectively with dopamine receptor agonist, benzodiazepine and opioid. However, few reports have objectively assessed the treatment responses. We treated a PLMS patient with clonazepam and pramipexole, and evaluated their efficacy with actigraphy. Clonazepam improved sleep quality without reducing frequency of limb movements, and pramipexole reduced frequency of limb movements without improving sleep quality, results which are consistent with previous study findings. Actigraphy proved useful in evaluation of treatment response of PLMS.