• The Journal of Korean Medicine
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• v.26 no.4
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• pp.12-21
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• 2005

Objectives: In the present study, we investigated whether an aqueous extract of Armeniacae semen induces apoptotic neuronal cell death upon mouse N2a neuroblastoma cells. Methods: 1. Cell viability was determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTI) assay. 2. For in situ detection of apoptotic cells, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining. 3. The fraction of cells was revealed by flow cytometric analysis used that. 4. For detection of apoptotic DNA cleavage, DNA fragmentation assay was performed. 5. For detection of bax and bcl-2, Western blot analysis was performed. 6. Caspase enzyme activity was measured using caspase-3 assay. Results: From the present results, N2a neuroblastoma cells treated with Armeniacae semen extract exhibited several characteristics of apoptosis. A treatment of Armeniacae semen extract was shown to increase the expression of Bax, a proapoptotic protein, and the treatment decreased the expression of Blc2, an anti-apoptotic protein. In addition, Armeniacae semen extract increased the caspase-3 enzyme activity. Conclusions: The present results show that Armeniacae semen extract induces apoptotic cell death in mouse N2a neuroblastoma cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.190-198
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• 2007

Alzheimer's disease, a representative neurodegenerative disorder, is characterized by the presence of senile plaques and neurofibrillary tangles accompanied by neuronal damages. b-Amyloid peptide is considered to be responsible for the formation of senile plagues that accumulate in the brains of patients with Alzheimer's disease. There has been compelling evidence supporting that b-amyloid-induced cytotoxicity is mediated through generation of reactive oxygen species. In this study, we have investigated the possible protective effect of Rehmannia glutihosaagainst b-amyloid-induced oxidative ceil death in cultured human neuroblastoma SH-SY5Y cells. SH-SY5Y cells treated with b-amyloid underwent apoptotic death as determined by morphological features and positive in situterminal end-labeling (TUNEL staining). Rehmannia glutinosawater extract, wine, and vinegar pretreatments attenuated b-amyloid-induced cytotoxicity and apoptosis. Rehmannia glutinosa vinegar exhibited maximum protective effect by increasing the expression of anti-apoptotic protein, Bcl-2. in addition to oxidative stress, b-amyloid-treatment caused nitrosative stress via marked increase in the levels of nitric oxide, which was effectively blocked by Rehmannia glutinosa. To further explore the possible molecular mechanisms underlying the protective effect of Rehmannia glutinosa, we assessed the mRNA expression of cellular antioxidant enzymes. Treatment of Rehmannia glutinosa vinegar led to up-regulation of heme oxygemase-1 and catalase. These results suggest that Rehmannia glutinosa could modulate oxidative neuronal cell death caused by b-amyloid and may have preventive or therapeutic potential in the management of Alzheimer's disease. Particularly, Rehmannia glutinosa vinegar can augment cellular antioxidant capacity, there by exhibiting higher neuroprotective potential.

• Korean Journal of Medicinal Crop Science
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• v.17 no.2
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• pp.145-150
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• 2009

This study investigated the protective roles and mechanism of magnolol, from the stem bark of Magnolia officinalis against potential neurotoxin 3-hydroxykynurenine (3-HK)-induced neuronal cell death. For the evaluation of protective role of magnolol, we examined cell viability, apoptotic nuclei, change of mitochondrial membrane potential and caspase activity in human neuroblastoma SH-SY5Y cells. It was found that 3-HK induces neuronal cell death in the human neuroblastoma SH-SY5Y cell line. The reduced cell viability produced characteristic features such as cell shrinkages, plasma membrane blebbing, chromatin condensation, and nuclear fragmentation. The cells treated with 3-HK showed an increase in the concentration of reactive oxygen species (ROS) as well as in caspase activity. In addition, both are involved in the 3-HK-induced apoptosis. Magnolol attenuated the cell viability reduction by 3-HK in both a dose- and time-dependent manner. Optical microscopy showed that magnolol inhibited the cell morphological features in the 3-HK-treated cells. Furthermore, the increase in the ROS concentration and the caspase activities by 3-HK were also attenuated by magnolol. These results showed that magnolol has a protective effect on the 3-HK induced cell death by inhibiting ROS production and caspase activity.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.2
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• pp.95-111
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• 2012

Objective : The water extract of Danguiyonghoihwan (DGYHW) has been traditionally used in treatment of tinnitus in Oriental Medicine. However, little is known about the mechanism by which DGYHW rescues auditory neuronal cells from injury damages. Therefore, in this study I effort to elucidate the mechanism of the cytoprotective effect of the DGYHW extract on glutamate-induced auditory sensorineuronal cell death. Methods : I determined the elevated cell viability by DGYHW extract on glutamate-induced auditory sensorineuronal cell death. Glutamate induced neuronal damage in oranotypic explant culture also, glutamate decreased cell viability on VOT-33 cells but pretreatment with DGYHW inhibited cell death. Results : One of the main mediator of glutamate-induced cytotoxicity was known to generation of reactive oxygen species (ROS). Pretreatment with DGYHW inhibited this ROS generation from glutamated-stimulated VOT-33 cells. Also, I identified that the ROS-induced DCF-DA green fluorescence is reduced by DGYHW pretreatment. The critical markers of apoptotic cell death were cleavages of procaspase-3 protease protein. So I checked the expression level and cleavage of procaspase-3 protease protein. Glutamate-treated VOT-33 cells were shown to have cleavage of procaspase-3 protease proteins and following reduction of expression of these proteins. But I found that pre-treatment with DGYHW protects glutamate-induced changes of biochemical marker protein, caspase-3. Conclusion : These findings indicated that DGYHW may prevent cell death from glutamate induced VOT-33 cell death by inhibiting the ROS generation and modulation of protein expressions in procaspase-3, catalase and Bcl-2.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.699-705
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• 1997

Although it is known that neuronal cell death during development occurs by apoptosis, the mechanisms underlying excitatory amino acid-induced neuronal cell death remain poorly understood. In this study we have examined the mechanism by which L-glutamate, an excitatory amino acid neurotransmitter, induces cell death in PC12 cell lines. To characterize cell death, we employed sandwich enzyme-linked immunosorbent assay(ELISA) method for cellular DNA fragmentation, DNA agarose gel electrophoresis and chromatin staining by acridine orange and ethidium bromide after treating the PC12 cells with L-glutamate. L-Glutamate caused dose-dependent cell death with a maximum at 24 hrs after the treatment. These cellular fragmentation was blocked by pretreatment of MK-801, a noncompetitive N-methyl-D-aspartic acid(NMDA) receptor antagonist, and nerve growth factor(NGF). Analysis of DNA integrity from L-glutamate-treated cells revealed cleavage of DNA into regular sized fragments, a biochemical hallmark of apoptosis. The PC12 cells that were induced to die by L-glutamate treatment exhibited classical chromatin condensation under the light microscopy after acridine orange and ethidium bromide staining. These results suggest that apoptosis is one of the key features that are involved in L-glutamate-induced excitotoxic cell death in PC12 cells, and these cell death are mediated by NMDA receptor and depend on NGF.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.4
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• pp.1-11
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• 2008

Objectives : Cerebral ischemia resulting from transient or permanent occlusion of cerebral arteries leads to neuronal cell death and eventually causes neurological impairments. Scrophulariae radix is the roots of Scrophularia buergeria. In the present study, we investigated the effects of the aqueous extract of Scrophulariae radix on apoptotic cell death in the hippocampal dentate gyrus following transient global ischemia in gerbils. Methods : For this study, step-down avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and immunohistochemistry for caspase-3 were performed. Results : The present results showed that apoptotic cell death in the hippocampal dentate gyrus was significantly increased following transient global ischemia in gerbils. Treatment with the aqueous extract of Scrophulariae radix suppressed the ischemia-induced apoptosis in the dentate gyrus and thus facilitated the recovery of short-term memory impairment induced by ischemic cerebral injury. Conclusions : Here in this study, we have shown that Scrophulariae radix has a positive effect on-and possesses protective qualities against ischemia-induced apoptotic neuronal cell death, and it can be used for the treatment of ischemic brain diseases.

• Journal of Korean Neurosurgical Society
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• v.54 no.1
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• pp.1-7
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• 2013

Objective : This study was undertaken in the belief that the atypical antipsychotic drug quetiapine could prevent apoptosis in the penumbra region following ischemia, taking into account findings that show 5-hydroxytryptamine-2 receptor blockers can prevent apoptosis. Methods : We created 5 groups, each containing 6 animals. Nothing was done on the K-I group used for comparisons with the other groups to make sure adequate ischemia had been achieved. The K-II group was sacrificed on the 1st day after transient focal cerebral ischemia and the K-III group on the 3rd day. The D-I group was administered quetiapine following ischemia and sacrificed on the 1st day while the D-II group was administered quetiapine every day following the ischemia and sacrificed on the 3rd day. The samples were stained with the immunochemical TUNEL method and the number of apoptotic cells were counted. Results : There was a significant difference between the first and third day control groups (K-II/K-III : p=0.004) and this indicates that apoptotic cell death increases with time. This increase was not encountered in the drug groups (D-I/D-II : p=1.00). Statistical analysis of immunohistochemical data revealed that quetiapine decreased the apoptotic cell death that normally increased with time. Conclusion : Quetiapine is already in clinical use and is a safe drug, in contrast to many substances that are used to prevent ischemia and are not normally used clinically. Our results and the literature data indicate that quetiapine could help both as a neuronal protector and to resolve neuropsychiatric problems caused by the ischemia in cerebral ischemia cases.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.195-200
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• 2011

Neuronal cell death is a common characteristic feature of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases. In the present study, docosyl cafferate (DC), a derivative of caffeic acid, was isolated from Rhus verniciflua and its protective effects on tBHP-induced neuronal cell death were examined in SH-SY5Y human neuroblastoma cells. Pretreatment of DC significantly attenuated tBHP-induced neuronal cell death in a concentration-dependent manner. DC also significantly suppressed tBHP-induced caspase-3 activation. In addition, DC restored tBHP-induced depletion of intracellular Bcl-2, an anti-apoptotic member of the Bcl-2 family. Furthermore, DC significantly suppressed tBHP-induced degradation of IKB, which retains $NF-{\kappa}B$ in the cytoplasm, resulting in the suppression of nuclear translocation of $NF-{\kappa}B$ and its subsequent activation. Taken together, the results clearly demonstrate that DC exerts its neuroprotective activity against tBHP-induced oxidative stress through the suppression of nuclear translocation of $NF-{\kappa}B$.

• BMB Reports
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• v.35 no.3
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• pp.267-272
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• 2002

TNF-$\alpha$ elicits various responses including apoptosis, proliferation, and differentiation according to cell type. In neuronal PC12 cells, TNF-$\alpha$ induces moderate apoptosis while lipopolysarccaharide or trophic factor deprivation can potentiate apoptosis that is induced by TNF-$\alpha$. TNF-$\alpha$ initiates various signal transduction pathways leading to the activation of the caspase family, NF-${\kappa}B$, Jun N-terminal kinase, and p38 MAPK via the death domain that contains the TNF-$\alpha$ receptor. Inhibition of translation using cycloheximide greatly enhanced the apoptotic effect of TNF-$\alpha$. This implies that the induction of anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic Bcl-2 family member, was highly expressed in response to TNF-$\alpha$. In this study, we examined the anti-apoptotic role of p38 MAPK that is activated by TNF-$\alpha$ in neuronal PC12 cells. The phosphorylation of p38 MAPK in response to TNF-$\alpha$ slowly increased and lasted several hours in the PC12 cell and DRG neuron. This specific inhibitor of p38 MAPK, SB202190, significantly enhanced the apoptosis that was induced by TNF-$\alpha$ in PC12 cells. This indicates that the activation of p38 MAPK could protect PC12 cells from apoptosis since there is no known role of p38 MAPK in resoonse to TNF-$\alpha$ in neuron. This discovery could be evidence for the neuroprotective role of the p38 MAPK.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.13-24
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• 2006

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride $(CoCl_2)$ has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG), a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by $CoCL_2$ and effects of EGCG on $CoCl_2-induced$ apoptosis in PC12 cells. Administration of $CoCl_2$ decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with $100{\mu}M$ EGCG for 30 min before PC12 cells were exposed to $150{\mu}M$ $CoCl_2$, being resulted in the cell viability and DNA fragmentation being rescued. $CoCl_2$ caused morphologic changes such as cell swelling and condensed nuclei whereas EGCG attenuated morphologic changes by $CoCl_2$. EGCG suppressed the apoptotic peak and a loss of ${\Delta}{\psi}_m$ induced by $CoCl_2$. $CoCl_2$ decreased Bcl-2 expression but Bax expression was not changed in $CoCl_2$- treated cells. EGCG attenuated the Bcl-2 underexpression by $CoCl_2$. $CoCl_2$ augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by $CoCl_2$ NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated $CoCl_2-induced$ apoptosis in consistent with those of EGCG. These results suggest that $CoCl_2$ induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against $CoCl_2-induced$ apoptosis in PC12 cells.