• Journal of Applied Biological Chemistry
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• 제61권4호
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• pp.397-403
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• 2018

조팝나무(Spiraea prunifolia) 잎을 80% MeOH 수용액으로 추출한 뒤, 감압 농축한 추출물을 EtOAc, n-BuOH과 $H_2O$층으로 계통 분획을 실시하였다. n-BuOH분획에 대하여 $SiO_2$, ODS column chromatograph 및 중압분취 장비를 반복실시하여 2종의 phenolic glucoside화합물을 분리 및 정제하였다. NMR 및 Mass데이터를 해석하여, isosalicin (1)와 crenatin (2)로 구조 동정 하였다. 분리한 2종의 화합물에 대하여 UPLC-MS/MS 질량 분석기를 기반으로 다중반응검지 (MRM mode) 분석법을 이용하여 정량분석 하였다. 그 결과, crenatin은 9.53 mg/g 및 isosalicin은 0.65 mg/g이 조팝나무 잎 추출물에 함유된 것을 확인하였다. 조팝나무 잎에서 분리된 화합물이 $H_2O_2$에 의해 유발된 산화스트레스로부터 신경세포 보호효과를 검증한 결과, 신경모세포종인 SK-N-MC 세포에 대해서 화합물 1 및 2 (100 mM) 모두 세포 독성은 보이지 않았으며, 특히 화합물 2 (crenatin)는 $H_2O_2$처리에 따른 신경세포의 외형적 변화, 세포 손상, 세포 사멸을 억제하여 산화스트레스로부터 신경세포를 보호하는 효과가 있음을 확인하였다.

• Journal of Ginseng Research
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• 제46권3호
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• pp.348-356
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• 2022

Background: Gintonin is a ginseng-derived exogenous G-protein-coupled lysophosphatidic acid (LPA) receptor ligand. Gintonin exerts its neuronal and non-neuronal in vitro and in vivo effects through LPA receptor subtypes. However, it is unknown whether gintonin can bind to the plasma membrane of cells and can transactivate the epidermal growth factor (EGF) receptor. In the present study, we examined whether gintonin-biotin conjugates directly bound to LPA receptors and transactivated the EGF receptor. Methods: We designed gintonin-biotin conjugates through gintonin biotinylation and examined whether gintonin-biotin conjugate binding sites co-localized with the LPA receptor subtype binding sites. We further examined whether gintonin-biotin transactivated the EGF receptor via LPA receptor regulation via phosphor-EGF and cell migration assays. Results: Gintonin-biotin conjugates elicit [Ca²⁺]_i transient similar to that observed with unbiotinylated gintonin in cultured PC3 cells, suggesting that biotinylation does not affect physiological activity of gintonin. We proved that gintonin-biotin conjugate binding sites co-localized with the LPA1/6 receptor binding sites. Gintonin-biotin binding to the LPA1 receptor transactivates the epidermal growth factor (EGF) receptor through phosphorylation, while the LPA1/3 receptor antagonist, Ki16425, blocked phosphorylation of the EGF receptor. Additionally, an EGF receptor inhibitor AG1478 blocked gintonin-biotin conjugate-mediated cell migration. Conclusions: We observed the binding between ginseng-derived gintonin and the plasma membrane target proteins corresponding to the LPA1/6 receptor subtypes. Moreover, gintonin transactivated EGF receptors via LPA receptor regulation. Our results suggest that gintonin directly binds to the LPA receptor subtypes and transactivates the EGF receptor. It may explain the molecular basis of ginseng physiology/pharmacology in biological systems.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.252-259
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• 2016

Neuropathic pain is a complex state showing increased pain response with dysfunctional inhibitory neurotransmission. The TREK family, one of the two pore domain $K^+$ (K2P) channel subgroups were focused among various mechanisms of neuropathic pain. These channels influence neuronal excitability and are thought to be related in mechano/thermosensation. However, only a little is known about the expression and role of TREK-1 and TREK-2, in neuropathic pain. It is performed to know whether TREK-1 and/or 2 are positively related in dorsal root ganglion (DRG) of a mouse neuropathic pain model, the chronic constriction injury (CCI) model. Following this purpose, Reverse Transcription Polymerase Chain Reaction (RT-PCR) and western blot analyses were performed using mouse DRG of CCI model and compared to the sham surgery group. Immunofluorescence staining of isolectin-B4 (IB4) and TREK were performed. Electrophysiological recordings of single channel currents were analyzed to obtain the information about the channel. Interactions with known TREK activators were tested to confirm the expression. While both TREK-1 and TREK-2 mRNA were significantly overexpressed in DRG of CCI mice, only TREK-1 showed significant increase (~9 fold) in western blot analysis. The TREK-1-like channel recorded in DRG neurons of the CCI mouse showed similar current-voltage relationship and conductance to TREK-1. It was easily activated by low pH solution (pH 6.3), negative pressure, and riluzole. Immunofluorescence images showed the expression of TREK-1 was stronger compared to TREK-2 on IB4 positive neurons. These results suggest that modulation of the TREK-1 channel may have beneficial analgesic effects in neuropathic pain patients.

• 대한신경과학회지
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• 제35권1호
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• pp.8-15
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• 2017

Near-infrared spectroscopy (NIRS), a noninvasive optical method, utilizes the characteristic absorption spectra of hemoglobin in the near-infrared range to provide information on cerebral hemodynamic changes in various clinical situations. NIRS monitoring have been used mainly to detect reduced perfusion of the brain during orthostatic stress for three common forms of orthostatic intolerance (OI); orthostatic hypotension, neurally mediated syncope, and postural orthostatic tachycardia syndrome. Autonomic function testing is an important diagnostic test to assess their autonomic nervous systems for patients with symptom of OI. However, these techniques cannot measure dynamic changes in cerebral blood flow. There are many experimentations about study of NIRS to reveal the pathophysiology of patients with OI. Research using NIRS in other neurologic diseases (stroke, epilepsy and migraine) are ongoing. NIRS have been experimentally used in all stages of stroke and may complement the established diagnostic and monitoring tools. NIRS also provide pathophysiological approach during rehabilitation and secondary prevention of stroke. The hemodynamic response to seizure has long been a topic for discussion in association with the neuronal damage resulting from convulsion. One critical issue when unpredictable events are to be detected is how continuous NIRS data are analyzed. Besides, NIRS studies targeting pathophysiological aspects of migraine may contribute to a deeper understanding of mechanisms relating to aura of migraine. NIRS monitoring may play an important role to trend regional hemodynamic distribution of flow in real time and also highlights the pathophysiology and management of not only patients with OI symptoms but also those with various neurologic diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.371-376
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• 2017

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion ($O_2{^-}$), on membrane excitability in the rat MDH neurons. For this, we used patch clamp recording and confocal imaging. An application of X/XO ($300{\mu}M/30mU$) induced membrane depolarization and inward currents. When slices were pretreated with ROS scavengers, such as phenyl N-tert-butylnitrone (PBN), superoxide dismutase (SOD), and catalase, X/XO-induced responses decreased. Fluorescence intensity in the DCF-DA and DHE-loaded MDH cells increased on the application of X/XO. An anion channel blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), significantly decreased X/XO-induced depolarization. X/XO elicited an inward current associated with a linear current-voltage relationship that reversed near -40 mV. X/XO-induced depolarization reduced in the presence of $La^{3+}$, a nonselective cation channel (NSCC) blocker, and by lowering the external sodium concentration, indicating that membrane depolarization and inward current are induced by influx of $Na^+$ ions. In conclusion, X/XO-induced ROS modulate the membrane excitability of MDH neurons, which was related to the activation of NSCC.

• The Korean Journal of Physiology and Pharmacology
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• 제20권2호
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• pp.185-192
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• 2016

Ampicillin, a ${\beta}$-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ischemia, ampicillin (200 mg/kg, intraperitoneally [i.p.]) or penicillin G (6,000 U/kg or 20,000 U/kg, i.p.) was administered daily for 5 days. The pretreatment with ampicillin but not with penicillin G significantly attenuated neuronal damage in the hippocampal CA1 subfield. Mechanistically, the increased activity of matrix metalloproteinases (MMPs) following forebrain ischemia was also attenuated by ampicillin treatment. In addition, the ampicillin treatment reversed increased immunoreactivities to glial fibrillary acidic protein and isolectin B4, markers of astrocytes and microglia, respectively. Furthermore, the ampicillin treatment significantly increased the level of glutamate transporter-1, and dihydrokainic acid (DHK, 10 mg/kg, i.p.), an inhibitor of glutamate transporter-1 (GLT-1), reversed the neuroprotective effect of ampicillin. Taken together, these data indicate that ampicillin provides neuroprotection against ischemia-reperfusion brain injury, possibly through inducing the GLT-1 protein and inhibiting the activity of MMP in the mouse hippocampus.

• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.125-131
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• 2017

Status epilepticus is the most common serious neurological condition triggered by abnormal electrical activity, leading to severe and widespread cell loss in the brain. Lithium has been one of the main drugs used for the treatment of bipolar disorder for decades, and its anticonvulsant and neuroprotective properties have been described in several neurological disease models. However, the therapeutic mechanisms underlying lithium's actions remain poorly understood. The muscarinic receptor agonist pilocarpine is used to induce status epilepticus, which is followed by hippocampal damage. The present study was designed to investigate the effects of lithium post-treatment on seizure susceptibility and hippocampal neuropathological changes following pilocarpine-induced status epilepticus. Status epilepticus was induced by administration of pilocarpine hydrochloride (320 mg/kg, i.p.) in C57BL/6 mice at 8 weeks of age. Lithium (80 mg/kg, i.p.) was administered 15 minutes after the pilocarpine injection. After the lithium injection, status epilepticus onset time and mortality were recorded. Lithium significantly delayed the onset time of status epilepticus and reduced mortality compared to the vehicle-treated group. Moreover, lithium effectively blocked pilocarpine-induced neuronal death in the hippocampus as estimated by cresyl violet and Fluoro-Jade B staining. However, lithium did not reduce glial activation following pilocarpine-induced status epilepticus. These results suggest that lithium has a neuroprotective effect and would be useful in the treatment of neurological disorders, in particular status epilepticus.

• Journal of Nutrition and Health
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• 제33권1호
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• pp.5-12
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• 2000

The control of food intake is a complex phenomenon caused by interactions between central and peripheral control mechanisms. The hypothalamic and brain stem regions have been identified as centers for food intake and energy expenditure in animals and humans. Of these, the ventromedial and lateral hypothalamic areas are involved in the control of food intake. Also, large amounts of neurotransmitters known to be involved in feeding are present in the hippocampus. Paricularly, tryptophan hydroxylase(TPH), known as a factor in the control of food intake, is present in high levels in the paraventricular nucleus of the hypothalamus and the hippocampus. In this study, TPH expression levels in the hypothalamic and hippocampal regions of fasting, anorexia mutant, and control mice were compared using RT-PCR and immunohistochemical methods. Differences in body weight among the fasting, anorexia mutant, and control groups wire observed. No statistical significance was noted in the number of TPH-immunoactivity in the hypothalamic nuclei, but relatively higher populations of such fibers were observed in the fasting group : the control group yielded samples with an overall value of 170.3${\pm}$3.5 in terms of immunoreactivity-induced optical density, whereas the fasting group yielded a value of 168.3${\pm}$2.6, and the anorexia mutant group 171.3${\pm}$0.8(lower values represent higher immunoreactivity), In fasting mice, stained neuronal bodies were observed in the CA3 and dentate gyrus regions of the hippocampus, which was different from the hippocampal regions of the control and anorexia mutant mice. The RT-PCR procedures were performed using whole brains, precluding any statistically noticeable findings in relation to specific regions, although the fasting and anorexia mutant groups showed 123.3% and 102.9%, respectively, of the TPH mRNA level in the control. The overall results present evidences of the role of TPH in the decrease in food intake during fasting caused by exogenic factors and in genetically acquired anorexia. (Korean J Nutrition 33(1) : 5-12, 2000)

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제19권1호
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• pp.13-18
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• 2008

Objectives : Internet addiction or pathologic internet use is one of the major mental health problems in children and adolescents in Korea. Internet addiction is defined as uncontrollable, markedly time-consuming internet use, which lasts for a period of at least six months. Internet addiction results in poor academic performance and negative parent-child relationships. By using $^{18}F$-fluorodeoxyglucose-positron emission tomography (FDG-PET), we investigated the effects of internet addiction on functional changes occurring in the adolescent brain. Methods : Adolescent patients with an internet addiction (4 boys and 2 girls; $15.6{\pm}1.2$ years) participated in this study. Eight healthy young adults (5 males and 3 females; 18-30 years old) with no previous history of psychiatric illness also participated as normal controls. Brain FDG-PET data was obtained with the participants in the resting condition and with no addictive stimuli. Results : Statistic parametric mapping analysis of the brain FDG-PET data revealed hypometabolic changes in the visual information processing circuits and hypermetabolic changes in the prefrontal areas in the adolescents with internet addiction, as compared with normal controls (p<.001). Conclusion : These results suggest a neuronal adaptation to excessive visual stimulation and synaptic plasticity due to internet addiction.

• Nutrition Research and Practice
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• 제14권1호
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• pp.3-11
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• 2020

BACKGROUND/OBJECTIVES: Oxidative stress causes cell damage and death, which contribute to the pathogenesis of neurodegenerative diseases. Urolithin A (UA), a gut microbial-derived metabolite of ellagitannins and ellagic acid, has high bioavailability and various health benefits such as antioxidant and anti-inflammatory effects. However, it is unknown whether it has protective effects against oxidative stress-induced cell death. We investigated whether UA ameliorates H₂O₂-induced neuronal cell death. MATERIALS/METHODS: We induced oxidative damage with 300 μM H₂O₂ after UA pretreatment at concentrations of 1.25, 2.5, and 5 μM in SK-N-MC cells. Cytotoxicity and cell viability were determined using the CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using a 2,7-dichlorofluorescein diacetate assay. Hoechst 33342 staining was used to characterize morphological changes in apoptotic cells. The expressions of apoptosis proteins were measured using Western blotting. RESULTS: UA significantly increased cell viability and decreased intracellular ROS production in a dose-dependent manner in SK-N-MC cells. It also decreased the Bax/Bcl-2 ratio and the expressions of cytochrome c, cleaved caspase-9, cleaved caspase-3, and cleaved PARP. In addition, it suppressed the phosphorylation of the p38 mitogen-activated protein kinase (MAPK) pathway. CONCLUSIONS: UA attenuates oxidative stress-induced apoptosis via inhibiting the mitochondrial-related apoptosis pathway and modulating the p38 MAPK pathway, suggesting that it may be an effective neuroprotective agent.