• The Korea Journal of Herbology
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• v.23 no.3
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• pp.1-9
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• 2008

Objectives : This research was performed to investigate protective effect of Sophora Subprostrata against transient global ischemic damage after 5-min two vessel occlusion. Methods : Gerbils were divided into three groups: Normal group, 5-min two vessel occlusion (2VO) group, Sophora Subprostrata administrated group after 2VO. The CCAs were occluded by microclip for 5min. Sophora Subprostrata was administrated orally(12mg/ml) for 7 days after 2VO. The histological and immunohistochemistrical analysis was performed at 72 hours and 7 days after the surgery each. For histological analysis, the brain tissue was stained with 1% cresyl violet solution and Immunohistochemistry for BAX and Bcl-2 was carried out to examine effect of Sophora Subprostrata on ischemic brain tissue. Results : The results showed that (1) Sophora Subprostrata has the protective effect against ischemia in CA1 area of the gerbil hippocampus 7 days after 5-minute occlusion, (2) the treatment of Sophora Subprostrata inhibits the expression of Bax relatively after 2VO-induced ischemia. That protective effect of the Sophora Subprostrata seems to be performed by regulating the proportion of Bax and Bcl-2 protein, (3) in hypoxia/reperfusion model using PC12 cell, the Sophora Subprostrata extract has the protective effect against ischemia in the dose of $2{\mu}/m{\ell}$ and $20{\mu}/m{\ell}$.This study suggests that Sophora Subprostrata has neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils and that Sophora Subprostrata regulates the proportion of Bax and Bcl-2 protein following ischemia. And, Sophora Subprostrata extract has protective effects also on a hypoxia/reperfusion cell culture model using PC12 cell. Conclusions : Sophora Subprostrata has protective effects against ischemic brain damage at the early stage of ischemia.

• Journal of Korean Neurosurgical Society
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• v.55 no.3
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• pp.125-130
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• 2014

Objective : This study was conducted to elucidate neuroprotective effect of carnosine in early stage of stroke. Methods : Early stage of rodent stroke model and neuroblastoma chemical hypoxia model was established by middle cerebral artery occlusion and antimycin A. Neuroprotective effect of carnosine was investigated with 100, 250, and 500 mg of carnosine treatment. And antioxidant expression was analyzed by enzyme linked immunosorbent assay (ELISA) and western blot in brain and blood. Results : Intraperitoneal injection of 500 mg carnosine induced significant decrease of infarct volume and expansion of penumbra (p<0.05). The expression of superoxide dismutase (SOD) showed significant increase than in saline group in blood and brain (p<0.05). In the analysis of chemical hypoxia, carnosine induced increase of neuronal cell viability and decrease of reactive oxygen species (ROS) production. Conclusion : Carnosine has neuroprotective property which was related to antioxidant capacity in early stage of stroke. And, the oxidative stress should be considered one of major factor in early ischemic stroke.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.105-110
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• 2009

Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. Erythropoietin (Epo) has been shown to exert neuroprotective effects in various brain injury models although the exact mechanisms through which Epo functions are not completely understood. This study investigates the effect of Epo on hypoxic-ischemic (HI) brain injury and the possibility that its neuroprotective actions may be associated with iron-mediated metabolism. Methods : HI brain injury was produced in 7-day-old rats by unilateral carotid artery ligation followed by hypoxia with 8% oxygen for 2 h. At the end of HI brain injury, the rats received an intraperitoneal injection of 5,000 units/kg erythropoietin. Random premedication with iron, deferoxamine, iron-deferoxamine, or saline were performed 23 d before HI brain injury. The severity of the brain injury was assessed at 7 d after HI. Results : Single Epo treatment post-HI brain injury reduced the gross and histopathological findings of brain injury. Iron premedication did not increase the incidence or severity of the injury as measured by the damage score. Deferoxamine administration before HI brain injury improved the brain injury as compared to no treatment or Epo treatment. Conclusion : These findings indicate that Epo provides neuroprotective benefits after HI in the developing brain. These findings suggest that Epos neuroprotective actions may involve reducing iron in tissues that mediate the formation of free radicals.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.199.1-199.1
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• 2003

Ischemia-induced changes in protein expression may provide important insights into the mechanisms of cellular damage and their potential recovery. In the present study, to investigate protein patterns changed in ischemic condition, the cortical and striatal tissue samples from the permanent and transient ischemic rat brain obtained by middle cerebral occlusion were analysed by proteomic approchese using 20-PAGE and MALOI-MS. (omitted)

• Neonatal Medicine
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• v.16 no.2
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• pp.221-233
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• 2009

Purpose: Erythropoietin (EPO) has neuroprotective effects in many animal models of brain injury, including hypoxic-ischemic (HI) encephalopathy, trauma, and excitotoxicity. Current studies have demonstrated the neuroprotective effects of EPO, but limited data are available for the neonatal periods. Here in we investigated whether recombinant human EPO (rHuEPO) can protect the developing rat brain from HI injury via modulation of NMDA receptors. Methods: In an in vitro model, embryonic cortical neuronal cell cultures from Sprague-Dawley (SD) rats at 19-days gestation were established. The cultured cells were divided into five groups: normoxia (N), hypoxia (H), and 1, 10, and 100 IU/mL rHuEPO-treated (H+E1, H+ E10, and H+E100) groups. To estimate cell viability and growth, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was done. In an in vivo model, left carotid artery ligation was performed on 7-day-old SD rat pups. The animals were divided into six groups; normoxia control (NC), normoxia Sham-operated (NS), hypoxia-ischemia only (H), hypoxia-ischemia+vehicle (HV), hypoxia-ischemia+rHuEPO before a HI injury (HE-B), and hypoxia-ischemia+rHuEPO after a HI injury (HE-A). The morphologic changes following brain injuries were noted using hematoxylin and eosin (H/E) staining. Real-time PCR using primers of subunits of NMDA receptors (NR1, NR2A, NR2B, NR2C and NR2D) mRNA were performed. Results: Cell viability in the H group was decreased to less than 60% of that in the N group. In the H+E1 and H+E10 groups, cell viability was increased to >80% of the N group, but cell viability in the H+E100 group did not recover. The percentage of the left hemisphere area compared the to the right hemisphere area were 98.9% in the NC group, 99.1% in the NS group, 57.1% in the H group, 57.0% in the HV group, 87.6% in the HE-B group, and 91.6% in the HE-A group. Real-time PCR analysis of the expressions of subunits of NMDA receptors mRNAs in the in vitro and in vivo neonatal HI brain injuries generally revealed that the expression in the H group was decreased compared to the N group and the expressions in the rHuEPO-treated groups was increased compared to the H group. Conclusion: rHuEPO has neuroprotective property in perinatal HI brain injury via modulation of N-methyl-D-aspartate receptors.

• Clinical and Experimental Pediatrics
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• v.62 no.12
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• pp.444-449
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• 2019

Background: Sixty percent of infants with severe neonatal hypoxic-ischemic encephalopathy die, while most survivors have permanent disabilities. Treatment for neonatal hypoxic-ischemic encephalopathy is limited to therapeutic hypothermia, but it does not offer complete protection. Here, we investigated whether hypoxia-inducible factor (HIF) promotes cell survival and suggested neuroprotective strategies. Purpose: HIF-1α deficient mice have increased brain injury after neonatal hypoxia-ischemia (HI), and the role of HIF-2α in HI is not well characterized. Copper-zinc superoxide dismutase (SOD)1 overexpression is not beneficial in neonatal HI. The expression of HIF-1α and HIF-2α was measured in SOD1 overexpressing mice and compared to wild-type littermates to see if alteration in expression explains this lack of benefit. Methods: On postnatal day 9, C57Bl/6 mice were subjected to HI, and protein expression was measured by western blotting in the ipsilateral cortex of wild-type and SOD1 overexpressing mice to quantify HIF-1α and HIF-2α. Spectrin expression was also measured to characterize the mechanism of cell death. Results: HIF-1α protein expression did not significantly change after HI injury in the SOD1 overexpressing or wild-type mouse cortex. However, HIF-2α protein expression increased 30 minutes after HI injury in the wild-type and SOD1 overexpressing mouse cortex and decreased to baseline value at 24 hours after HI injury. Spectrin 145/150 expression did not significantly change after HI injury in the SOD1 overexpressing or wild-type mouse cortex. However, spectrin 120 expression increased in both wild-type and SOD1 overexpressing mouse at 4 hours after HI, which decreased by 24 hours, indicating a greater role of apoptotic cell death. Conclusion: HIF-1α and HIF-2α may promote cell survival in neonatal HI in a cell-specific and regional fashion. Our findings suggest that early HIF-2α upregulation precedes apoptotic cell death and limits necrotic cell death. However, the influence of SOD was not clarified; it remains an intriguing factor in neonatal HI.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.255-261
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• 2010

Ischemic stroke, a major cause of death and disability worldwide, is caused by occlusion of cerebral arteries that, coupled with or without reperfusion, results in prolonged ischemia (hypoxia and hypoglycemia) and, ultimately, brain damage. In this study, we examined whether methanol extract of the whole plant of Cassia mimosoides var. nomame Makino that grows naturally in Korea, as well as Japan and China, and some of its fractions obtained by partitioning with organic solvents could protect human hepatocellular carcinoma cells (HepG2) under hypoxic condition by inhibiting apoptosis. We also investigated if these extracts could attenuate brain damage in a rat model of 2 hr of ischemia, generated by middle cerebral artery occlusion, and 22 hr of reperfusion. The whole extract ($100{\mu}g$/mL) maintained the cell number at more than half of that initially plated, even after 24 hr of cell culture under hypoxic condition (3% $O_2$). In the absence of the whole extract, almost all of the cells were dead by this time point. This improvement of cell viability came from a delay of apoptosis, which was confirmed by observing the timing of the formation of a DNA ladder when assessed by gel electrophoresis. Of fractions soluble in hexane, ethyl acetate (EA), butanol and water, EA extracts were selected for the animal experiments, as they improved cell viability at the lowest concentration ($10{\mu}g$/mL). The whole extract (200 mg/kg) and EA extract (10 and 20 mg/kg) significantly reduced infarct size, a measure of brain damage, by 34.7, 33.8 and 45.2.0%, respectively, when assessed by 2,3,5-triphenyl tetrazolium chloride staining. The results suggest that intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic stroke through inhibition of brain cell apoptosis.

• Korean Journal of Veterinary Service
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• v.29 no.4
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• pp.469-482
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• 2006

The term 'heat shock protein (Hsps)' was derived from the fact that these proteins were initially discovered to be induced by hyperthermic conditions. In response to a range of stressful stimuli, including hyperthermia, immobilization, UV radiation, amino acid analogues, arsenite, various chemicals, and drugs the mammalian brain demonstrates a rapid and intense induction of the heat shock protein. Moreover, Hsps were expressed on the various pathological conditions including trauma, focal or global ischemia, hypoxia, infarction, infections, starvation, and anoxia. Especially, Hsp25 has a protective activity, facilitated by the ability of the protein to decrease the intracellular levels of reactive oxygen species (ROS) as well as its chaperone activity, which favors the degradation of oxidized proteins. Recently, it has clearly demonstrated that Hsp25 is constitutively expressed in the adult mouse cerebellum by parasagittal bands of purkinje cells in three distinct regions, the central zone (lobule VI-VII) and nodular zone (lobule IX-X), and paraflocculus. The Mongolian gerbil has been introduced into stroke study model because of its unique brain vasculature. There are no significant connections between the basilarvertebral system and the carotid system. This anatomy feature renders the mongolian gerbil susceptible to forebrain ischemia-induced seizure. The present study is designed to examine the pattern of Hsp25 expression in the cerebellum of this animal in comparison with that in mouse.

• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.181-188
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• 2017

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.3
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• pp.741-747
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• 2007

This study evaluated neuroprotective effects of Yanggyuksanhwa-tang (YST), which have been known to be efficacy in the treatment of the stroke and diabetes. on focal cerebral ischemia of diabetic rats. On primary experiment, diabetic condition in rats was induced by streptozotocin injection, then, focal cerebral ischemia was induced by the middle cerebral artery occlusion (MCAO) under the diabetic condition. Then neuroprotective effect of YST was observed with changes of infarct size and volume, expressions of c-Fos, Bax, and hypoxia inducible factor (HIF)-1${\alpha}$ in the brain tissues by using 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining and immunohistochemistry. YST treatment showed a significant decrease of infarct size and volume induced by MCAO in diabetic rats. YST treatment showed a significant decrease of c-Fos and Bax positive neurons in cortex penumbra. YST treatment showed a decrease of HIF-l${\alpha}$ positive neurons in cortex penumbra, but it was not significant statistically. These results suggest that YST has effects on neuroprotection against cerebral infarct under diabetic condition. And it is supposed that neuroprotective effect of YST reveals by anti-apoptosis mechanism.