• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.9-22
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• 1993

To evaluate the protective effects of calcium antagonists, oxygen radical scavengers and excitatory amino acid (EAA) antagonist on the ischemic brain damage, we induced in vitro ischemic condition (namely, lack of oxygen and glucose) to rat hippocampal slices. And the degree of ischemic damage was determined by assaying changes in biochemical parameters such as ATP content and lactate ralease, MDA production in the presence or absence of the various drugs. During experimental ischemia for up to 60 min, ATP content was decreased and the amount of lactate release was markedly increased time-dependently. By changing the reaction medium which contained oxygen and glucose those biochemical parameters were recovered. But the recovery was not complete in this experimental condition. In the same ischemic conditions verapamil and vitamine E prevented the decrease of ATP content and the increase of lactate release from the slices. And verapamil and diltiazem decreased MDA release to the reaction medium. Superoxide dismutase (SOD) and MK-801 (as EAA receptor antagonist) protected the decrease of ATP content and reduced MDA release in 20 min ischemic condition, but glutathione affected ATP content and lactate release at the same condition. When oxygen and glucose were resupplied for 20 min after ischemic condition, verapamil showed the protective effect on the changes of ATP content and lactate release, and vitamine E decreased lactate release (at 20 min ischemia) and MDA release (at 60 min ischemia). These results showed that calcium antagonist and vitamine E protect the ischemic biochemical changes from rat hippocampal slices and calcium antagonist is more potent than vitamine E to protect the ischemical brain damege.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.71-71
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• 2003

Human umbilical cord blood cells(HUCBC) are rich in mesenchymal progenitor cells, endothelial cell precursors and hematopoietic cells. HUCBC have been used as a source of transplantable stem and progenitor cells. However, little is known about survival and development of HUCBC transplantation in the CNS. Estrogen has a neuroprotective potential against oxidative stress-induced cell death so has an effect on reducing infarct size of ischemic brain. We investigated the potential use of HUCBC as donor cells and tested whether estrogen mediates intravenously infused HUCBC enter and survive in ischemic brain. PKH26 labeled mononuclear fraction of HUCBC were injected into the tail vein of ischemic OVX rat brain with or without $17\beta$-estradiol valerate(EV). Under fluorescence microscopy, labeled cells were observed in the brain section. Significantly more cells were found in the ischemic brain than in the non-ischemic brain. HUCBC transplanted into ischemic brain could migrate and survive. Some of cells have shown neuronal like cells in hippocampus, striatum and cortex tissues. These result suggest that estrogen reduces ischemic damage and increases the migration of human umbilical cord blood cells. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) though the Biohealth Products Research Center(BPRC), Inje University, Korea.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.5
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• pp.275-280
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• 2008

A brief ischemic insult induces significant protection against subsequent massive ischemic events. The molecular mechanisms known as preconditioning (PC)-induced ischemic tolerance are not completely understood. We investigated whether kinetic changes of cyclooxygenase (COX)-2 during reperfusion time-periods after PC were related to ischemic tolerance. Rats were given PC by occlusion of middle cerebral artery (MCAO) for 10 min and sacrificed after the indicated time-periods of reperfusion (1, 2, 4, 8, 12, 18 or 24 h). In PC-treated rats, focal ischemia was induced by occlusion of MCA for 24 h and brain infarct volume was then studied to determine whether different reperfusion time influenced the damage. We report that the most significant protection against focal ischemia was obtained in rats with 8 h reperfusion after PC. Administration of indomethacin (10 mg/kg, oral) or rofecoxib (5 mg/kg, oral) 48 h prior to PC counteracted the effect of PC. Immunohistochemical analysis showed that COX-2 and HO-l protein were induced in PC-treated rat brain, which was significantly inhibited by rofecoxib. Taken together, we concluded that the kinetic changes of COX-2 expression during the reperfusion period after PC might be partly responsible for ischemic tolerance.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.853-860
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• 2000

Objective : The purpose of our experimental study was to analysis the advantages and disadvantages in the reversible and irreversible cerebral ischemic models with rats by staining with Neutral Red(NR) solusion, 2% 2,3,5-triphenyltetrazolium chloride(TTC) and Hematoxylin & Eosin(H & E). Methods : We have measured the range of cerebral infarction in the rat to get a suitable ischemic model along the object of study with and without craniectomy. With craniectomy, 9 rats were sacrificed for irreversible cerebral ischemic model by means of ligation at proximal(group I) and distal(group II), and coagulation at proximal(group III) middle cerebral artery. Also, 6 rats were sacrificed for irreversible(group IV) and reversible(group V) cerebral ischemic model using nylon thread without craniectomy. The sizes of infarction were measured by staining the coronal sections of the brain with NR solusion, TTC and H & E. Results : There are no difference of physiological parameters comparing the each group. Cerebral infarction was not observed in group II, but it's volume was largest in group IV. Disadvantages of craniectomy group(I, II, III) are the long duration of operation and cortical damage by procedure. It's advantage is confirmation of the middle cerebral artery occlusion and cessation of blood flow through the operative microscope. In case of ischemic models using nylon thread (group IV, V), it is hard to identify the interruption or recirculation of blood flow through the middle cerebral artery, but the advantage is the simplicity of operative technique which reduces the operation time and minimizes the cerebral damage due to craniectomy. Therefore, it seems important to set up the reversible and irreversible ischemic models by carefully considering advantages and disadvantages listed above. Conclusion : TTC staining seems to be effective since it reflects the histological damage sufficiently and quickly. It is hoped that researches focused on ischemic penumbra, which became popular recently, will be further carried on with use of NR staining, optical microscope and electron microscope.

• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.227-241
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• 2004

Objective : This study was performed to investigate neuroprotective effects of Bupleuri Radix against oxidative and ischemic damages. Method : To observe the neuroprotective effects against ischemic damage, ischemic insult was induced by oxygen/glucose deprivation (OGD) on organotypic hippocampal slice cultures (OHSC) from 1 week-old Sprague-Dawley rats. Propidium iodide (PI) fluorescence-stained neuronal dead-cell areas, area percentages and TUNEL-positive apoptotic cells in CA1 and dentate gyrus, and LDH levels in culture media of the OHSC were measured following Bupleuri Radix extract treatment. Result : The following results were obtained: (1) The $5\;{\mu}g/ml$ of Bupleuri Radix treatment demonstrated a significant decrease in PI fluorescence-stained neuronal dead-cell areas and area percentage in CA1 region of the OHSC from 18 hrs to 48 hrs following the OGD. The $50\;{\mu}g/ml$ of Bupleuri Radix treatment was also significant from 6 hrs to 48 hrs following the OGD and was more effective. (2) The 5 and $50\;{\mu}g/ml$ of Bupleuri Radix treatment demonstrated a significant decrease in PI fluorescence-stained neuronal dead-cell areas and area percentage in DG region of the OHSC from 6 hrs to 48 hrs following the OGD. The $50\;{\mu}g/ml$ treatment was more effective than the $5\;{\mu}g/ml$ treatment. (3) Bupleuri Radix treatment demonstrated a significant decrease in TUNEL-positive apoptotic cells in CA1 region (with 5 and $50\;{\mu}g/ml$) and in DG region (with $50\;{\mu}g/ml$) of the OHSC damaged by the OGD. (4) Bupleuri Radix treatment demonstrated a significant decrease in LDH concentrations in culture media of the OHSC damaged by the OGD. Conclusion : These results suggest that Bupleuri Radix has neuroprotective and control effects on inflammatory and immune responses where there has been ischemic damage to the central nervous system.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.13-27
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• 2009

This study aimed to validate neuroprotective effect of Chungpaesagan-tang on the early stage of cerebral ischemic damage. Cerebral ischemic damage was induced by the middle cerebral artery occlusion (MCAO) for 2 hours in the Sprague-Dawley rats. Water extract of Chungpaesagan-tang(8.7g/kg) was administered orally twice at 1 and 4 hours after the MCAO. Neurological score was tested at 3 and 24 hours after the MCAO and Chungpaesagan-tang administration. At 24 hours after the MCAO, infarct volume and edema ratio was evaluated with the TTC staining. Apoptotic cell death in cerebral cortex and caudate putamen was observed with cresyl violet staining and TUNEL labeling. Bax expression in the MCAO rat brain was stained with immunohistochemistry. Chungpaesagan-tang improved neurological and behavioral impairment of the MCAO rats and reduced infarct area, infarct volume and brain edema formation. Chungpaesagan-tang attenuated cell death percentage in cortex penumbra and reduced TUNEL positive cells in cortex penumbra and in caudate putamen of the MCAO rats. Chungpaesagan-tang reduced Bax positive neurons in caudate putamen and reduced c-Fos positive neurons in cortex penumbra of the MCAO rats. Chungpaesagan-tang intensified neuronal HSP72 expression in cortex penumbra of the MCAO rats. In results, Chunpaesagan-tang reduces infarct volume and edema formation through anti-apoptotic effect. This result suggests that Chunapaesagan-tang has an adequate neuroprotective effect on the early stage of cerebral ischemic damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.993-999
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• 2005

This research was peformed to investigate protective effect of Sophora Subprostrata fractions against focal ischemic brain damage after middle cerebral artery(MCA) occlusion using intraluminal suture. Rats were divided into six groups: MCA-occluded group(Control): each administered groups with Sophora Subprostrata total phase(Total), Sophora Subprostrata Aqueous phase (Aqueous), Sophora Subprostrata BuOH phase(BuOH), and Sophora Subprostrata Alkaloid phase(Alkaloid) after MCA-occlusion; sham-operated group(Sham). The right MCA was occluded by A poly-L-lysine coated 4-0 nylon suture thread through the internal carotid artery permanently. Sophora Subprostrata and fractions were administered orally(Smg/ml) for 7 days after MCA-occlusion. The Drain tissue was stained with $2\%$ triphenyl tetrazolium chloride on ischemic brain tissue(2mm section). The results showed that 1) Sophora Subprostrata total phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 2) Sophora Subprostrata Aqueous phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 3) Sophora Subprostrata Alkaloid phase reduced infarct size compared to the control group at 24 hours after MCA-occlusion, but 4) at 7 days after MCA-occlusion, Sophora Subprostrata did not show effective recovery compared with control group. Sophora Subprostrata has protective effects against brain damage at the early stage of focal cerebral ischemia. Sophora Subprostrata total and Aqueous phase produced more pronounced protective effect against focal ischemic brain damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.760-764
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• 2005

This research was performed to investigate protective effect of Sophora Subprostrata fractions against focal ischemic brain damage after middle cerebral artery(MCA) occlusion. Rats were divided into six groups: MCA-occluded group(Control); each administered groups with Sophora Subprostrata total phase(Total), Sophora Subprostrata Aqueous phase (Aqueous), Sophora Subprostrata BuOH phase(BuOH), and Sophora Subprostrata Alkaloid phase(Alkaloid) after MCA-occlusion; sham-operated group(Sham). The right MCA was occluded by A poly-L-lysine coated 4-0 nylon suture thread through the internal carotid artery permanently. Sophora Subprostrata and fractions were administered orally(5mg/ml) for 7 days after MCA-occlusion. The behavior of ischemic rats were examined at 24 hours, 3, 5 and 7 days after MCA-occlusion from the views of 4 different aspects: posture & balance tests(4 subtests), reflex tests(6 subtests), muscle-tone tests(3 subtests), and foot-fault test. The results showed that 1) in muscle tone test, Sophora Subprostrata total phase only increased reduced muscle tone function from 3 to 7 days, 2) in reflex test, Sophora Subprostrata total and Aqueous phase increased fast recovery from 24 hours and 3 days, 3) in posture & balance test, Sophora Subprostrata total and Aqueous phase increased fast recovery from 24 hours, and Sophora Subprostrata BuOH and Alkaloid phase increased posture & balance function from 3 days, but 4) in motor function test, Sophora Subprostrata did not show effective recovery compared with control group. In conclusion, Sophora Subprostrata has protective effects against brain damage at the early stage of focal cerebral ischemia. Sophora Subprostrata total and Aqueous phase produced more pronounced protective effect against focal ischemic brain damage.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.423-431
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• 2020

This study aimed to evaluate the effect of curcumin on brain hypoxic-ischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.94.1-94.1
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• 2003

This research was performed to investigate the protective effect of Chungpesagan-tang (CPS) against ischemic damage in PC12 cells. To elucidate the mechanism of the protective effect of CPS on ischemic insult, cell viability and changes in activities of Superoxide dismutase, Glutathione Peroxidase, Catalase, Caspase 3 and the production of Malondialdehyde were observed after treating PC12 cells with CPS which was metabolized by rat liver homogenate. Pretreatment of CPS with liver homogenate increased its protective effect against ischemic insult by reducing the harmful effect of CPS itself. (omitted)