• Laboraroty Animal Research
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• v.34 no.4
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• pp.195-202
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• 2018

Hyperglycemia is one of the major risk factors for stroke. Hyperglycemia can lead to a more extensive infarct volume, aggravate neuronal damage after cerebral ischemia. ${\alpha}$-Synuclein is especially abundant in neuronal tissue, where it underlies the etiopathology of several neurodegenerative diseases. This study investigated whether hyperglycemic conditions regulate the expression of ${\alpha}$-synuclein in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury. Male Sprague-Dawley rats were treated with streptozotocin (40 mg/kg) via intraperitoneal injection to induce hyperglycemic conditions. MCAO were performed four weeks after streptozotocin injection to induce focal cerebral ischemia, and cerebral cortex tissues were obtained 24 hours after MCAO. We confirmed that MCAO induced neurological functional deficits and cerebral infarction, and these changes were more extensive in diabetic animals compared to non-diabetic animals. Moreover, we identified a decrease in ${\alpha}$-synuclein after MCAO injury. Diabetic animals showed a more serious decrease in ${\alpha}$-synuclein than non-diabetic animals. Western blot and reverse-transcription PCR analyses confirmed more extensive decreases in ${\alpha}$-synuclein expression in MCAO-injured animals with diabetic condition than these of non-diabetic animals. It is accepted that ${\alpha}$-synuclein modulates neuronal cell death and exerts a neuroprotective effect. Thus, the results of this study suggest that hyperglycemic conditions cause more serious brain damage in ischemic brain injuries by decreasing ${\alpha}$-synuclein expression.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.357-363
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• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• Korean Journal of Exercise Nutrition
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• v.23 no.4
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• pp.26-31
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• 2019

[Purpose] Numerous epidemiological studies have shown that it is possible to prescribe exercise for neurodegenerative disease, such as Alzheimer's disease and Parkinson's disease. However, despite the availability of diverse scientific knowledge, the effects of exercise in this regard are still unclear. Therefore, this study attempted to investigate a substance, such as black chokeberry (Aronia melanocapa L.) that could improve the ability of the treatment and enhance the benefits of exercising in neurodegenerative diseases. [Methods] The cell viability was tested with 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolim-5-carboxanilide and the cells were stained with ethidium homodimer-1 solution. The mRNA expression levels were evaluated by microarray. The active compounds of black chokeberry ethanolic extract (BCE) were analyzed by gas chromatography. The chemical shift analysis in the brain was performed using magnetic resonance spectroscopy. [Results] BCE treatment decreased hydrogen peroxide-induced L6 cell death and beta amyloid induced primary neuronal cell death. Furthermore, BCE treatment significantly reduced the mRNA levels of the inflammatory factors, such as IL-1α, Cxcl13, IL36rn, Itgb2, Epha2, Slamf8, Itgb6, Kdm6b, Acvr1, Cd6, Adora3, Cd27, Gata3, Tnfrsf25, Cd40lg, Clec10a, and Slc11a1, in the primary neuronal cells. Next, we identified 16 active compounds from BCE, including D-mannitol. In vivo, BCE (administered orally at a dosage of 50 mg/kg) significantly regulated chemical shift in the brain. [Conclusion] Our findings suggest that BCE can serve as a candidate for neurodegenerative disease therapy owing to its cyto-protective and anti-inflammatory effects. Therefore, BCE treatment is expected to prevent damage to the muscles and neurons of the athletes who continue high intensity exercise. In future studies, it would be necessary to elucidate the effects of combined BCE intake and exercise.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.57-57
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• 2021

Oxygen glucose deprivation/re-oxygenation (OGD/R) induces neuronal injury via mechanisms that are believed to mimic the pathways associated with brain ischemia. Stachys sieboldii Miq. (Chinese artichoke), which has been extensively used in oriental traditional medicine to treat of ischemic stroke; however, the role of S. sieboldii Miq. (SSM) in OGD/R induced neuronal injury is not yet fully understood. The present research is aimed to investigate the protective effect and possible mechanisms of SSM extract treatment in an in vitro model of OGD/R to simulate ischemia/reperfusion Injury. Pretreatment of these cells with SSM significantly attenuated OGD/R-induced production of reactive oxygen species (ROS) by increasing GPx, SOD, and decreasing MDA. SSM decreased mitochondrial damage caused by OGD/R injury and inhibited the release of cyt-c from mitochondrion to cytoplasm in SH-SY5Y cells. Furthermore, neuronal cell apoptosis caused by OGD/R injury was inhibited by SSM, and SSM could decrease apoptosis by increasing ratio of Bcl-2/Bax and inhibiting caspase signaling pathway in SH-SY5Y cells. SSM demonstrated a neuroprotective effect on the simulated cerebral ischemia in vitro model, and this effect was the inhibition of mitochondria-mediated apoptosis pathway by scavenging of ROS generation. Therefore, SSM may be a promising neuroprotective strategy against ischemic stroke.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1008-1018
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• 2000

Objective : Glutamate induced excitotoxicity is one of the leading causes of cell death under pathologic condition. However, there is controversy whether excitotoxicity may also participate in the neuronal death under low intensity insult such as simple hypoxia or hypoglycemia. To investigate the role of NMDA receptor in low intensity insult, we chose anoxia as the method of injury and used organotypically cultured hippocampal slice as the material of experiment. Materials & Methods : The hippocampal slices cultured for 2-3 weeks were exposed to 60 minutes of complete oxygen deprivation(anoxia). Neuronal death was assessed with Sytox stain. Corrected optical density of fluorescence in gray scale, used as cellular death indicator, was obtained from pictures taken at 24 and 48 hours following the insult. The well-known in vivo phenomenon of regional difference in susceptibility of hippocampal sub-fields to ischemic insult was reproduced in HOSC(hippocampal organotypic slice culture) by complete oxygen deprivation injury. Results : $CA_1$ was the most vulnerable to complete oxygen deprivation in hippocampus while $CA_3$ was resistant. Oxygen deprivation for 10 and 20 minutes with glucose(6.5g/l) present was insufficient to induce neuronal death in the cultured hippocampal slice. However, after 30 minutes exposure under anoxic condition, neuronal death was able to be detected in the center of $CA_1$ area. The intensity and area of fluorescence indicating cell death correlated with the duration of oxygen deprivation. NMDA receptor and non-NMDA receptor blocking with MK-801(30 & $60{\mu}M$) and CNQX($100{\mu}M$) did not provide cellular protection to HOSC against damage induced by oxygen deprivation, but increased intracellular calcium buffering capacity with BAPTA-AM($10{\mu}M$) was effective in preventing neuronal death (p=0.01, Student's t-test). Cycloheximide($1{\mu}g/ml$, $10{\mu}g/ml$) provided no protection to HOSC against insult of complete oxygen deprivation for 60 minutes and combined therapy of MK-801(30 & $60{\mu}M$) and cycloheximide(1 & $10{\mu}g/ml$) was also ineffective in preventing neuronal death. Conclusion : The results of this study show that the another mechanism not associated with glutamate receptor(NMDA & non NMDA) may play major role in cell death mechanisms induced by complete oxygen deprivation and increased intracellular calcium during anoxia may participate in the neuronal death mechanism of oxygen deprivation. Further investigation of the calcium entry channel activated during oxygen deprivation is necessary to understand the neuronal death of anoxia.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.415-423
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• 2004

Myristica fragrans seed from Myristica fragrans Houtt (Myristicaceae) has various pharmacological activities peripherally and centrally. The present study aims to investigate the effect of the methanol extract of Myristica fragrans seed (MF) on kainic acid (KA)-induced neurotoxicity in primary cultured rat cerebellar granule neuron. MF, over a concentration range of 0.05 to $5\;{\mu}g/ml$ inhibited KA $(500\;{\mu}M)-induced$ neuronal cell death, which was measured by trypan blue exclusion test and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. MF $(0.5\;{mu}g/ml)$ inhibited glutamate release into medium induced by KA $(500\;{\mu}M)$, which was measured by HPLC. Pretreatment of MF $(0.5\;{mu}g/ml)$ inhibited KA $(500\;{\mu}M)-induced$ elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that MF prevents KA-induced neuronal cell damage in vitro.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1546-1551
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• 2005

This Study was designed to investigate the effects of Nelumbinis Rhizomatis Nodus (NRN) on the change of cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. And, this study was designed to investigate the inhibition of lactate dehydrogenase activity in neuronal cells The results were as follows NRN significantly increased rCBF and PAD in a dose-dependent manner, and NRN increased MABP in a dose-dependent manner. This results suggested that NRN significantly increased rCBF by dilating PAD. Both rCBF and PAD were significantly and stably increased by NRN (10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. NRN significantly inhibited lactate dehydrogenase activity in neuronal cells. This results suggested that NRN prevented the neuronal death. It is suggested that NRN had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1640-1646
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• 2005

An oriental medicinal drugs Jahageo (JHG, Hominis placenta) were examined to determine its effects on the responsiveness of central nervous system neurons after injury. We found that JHG was involved in neurite outgrowth of DRG sensory axons. JHG treatment also increased expression of axonal growth-associated protein GAP-43 in DRG sensory neurons after sciatic nerve injury and in the injured spinal cord. JHG treatment during the spinal cord injury increased induction levels of cell division cycle 2 (Cdc2) protein in DRG as well as in the spinal cord. Histochemical investigation showed that induced Cdc2 in the injured spinal cord was found in non-neuronal cells. These results suggest that JHG regulates activities of non-neuronal cells such as oligodendrocyte and astrocyte in responses to spinal cord injury and protects neuronal responsiveness after axonal damage.

• Korean Journal of Biological Psychiatry
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• v.30 no.1
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• pp.1-6
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• 2023

Many psychiatric disorders are associated with brain functional dysfunctions and neuronal degeneration. According to the research so far, enhanced brain plasticity reduces neurodegeneration and recovers neuronal damage. Brain-derived neurotrophic factor (BDNF) is one of the most extensively studied neurotrophins in the mammalian brain that plays major roles in neuronal survival, development, growth, and maintenance of neurons in brain circuits related to emotion and cognitive function. Also, BDNF plays an important role in brain plasticity, influencing dendritic spines in the hippocampus neurogenesis. Changes in neurogenesis and dendritic density can improve psychiatric symptoms and cognitive functions. BDNF has potent effects on brain plasticity through biochemical mechanisms, cellular signal pathways, and epigenetic changes. There are pharmacological and non-pharmacological interventions to increase the expression of BDNF and enhance brain plasticity. Non-pharmacological interventions such as physical exercise, nutritional change, environmental enrichment, and neuromodulation have biological mechanisms that increase the expression of BDNF and brain plasticity. Non-pharmacological interventions are cost-effective and safe ways to improve psychiatric symptoms.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.109.2-110
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• 2003

The neuroprotective effect of solvent fraction of native edible plant MK-104 in the mice administered with kainate was evaluated using behavioral sign, neuronal injuries and biomarkers of oxidative stress. Mice, ICR male, were administered with the BFME through a gavage for 4 days consecutively, and on the 3rd day, kainate (450 mg/kg) was i.p. administered. The fraction(400 mg/kg) delayed the onset time of neurobehavioral change (p<0.01), reduced the severity of convulsion and lethality (p<0.05), and restored the level of GSH and lipid peroxidation in brain to control value. A similar protective action was also expressed by fraction-I (200 mg/kg), which showed a prominent protection against the neuronal damage in hippocampal CA1 and CA2 regions (p<0.01) caused by kainate injection. of TBARS value. Based on these results, BFME-I is suggested to contain a functional agent to prevent against oxidative stress in the brain of mice.