• Biomedical Science Letters
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• v.15 no.3
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• pp.261-263
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• 2009

Methylprednisolone is a synthetic glucocorticoid which is usually taken intravenously for many neurosurgical diseases which cause edema including brain tumor, and trauma including spinal cord injury. Methylprednisolone reduces swelling and decreases the body's immune response. It is also used to treat many immune and allergic disorders, such as arthritis, lupus, psoriasis, asthma, ulcerative colitis, and Crohn's disease. To identify genes expressed during methylprednisolone treatment against neurons of rats (PC12 cells), DNA microarray method was used. We have isolated 2 gene groups (up- or down-regulated genes) which are methylprednisolone differentially expressed in neurons. Lipocalin 3 is the gene most significantly increased among 772 up-regulated genes (more than 2 fold over-expression) and Aristaless 3 is the gene most dramatically decreased among 959 down-regulated genes (more than 2 fold down-expression). The gene increased expression of Fgb, Thbd, Cfi, F3, Kngl, Serpinel, C3, Tnfrsf4 and Il8rb are involved stress-response gene, and Nfkbia, Casp7, Pik3rl, I11b, Unc5a, Tgfb2, Kitl and Fgf15 are strongly associated with development. Cell cycle associated genes (Mcm6, Ccnb2, Plk1, Ccnd1, E2f1, Cdc2a, Tgfa, Dusp6, Id3) and cell proliferation associated genes (Ccl2, Tnfsf13, Csf2, Kit, Pim1, Nr3c1, Chrm4, Fosl1, Spp1) are down-regulated more than 2 times by methylprednisolone treatment. Among the genes described above, 4 up-regulated genes are confirmed those expression by RT-PCR. We found that methylprednisolone is related to expression of many genes associated with stress response, development, cell cycle, and cell proliferation by DNA microarray analysis. However, We think further experimental molecular studies will be needed to figure out the exact biological function of various genes described above and the physiological change of neuronal cells by methylprednisolone. The resulting data will give the one of the good clues for understanding of methylprednisolone under molecular level in the neurons.

• Molecules and Cells
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• v.21 no.2
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• pp.237-243
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• 2006

Brain-derived neurotrophic factor (BDNF) is a neuromodulator of nociceptive responses in the dorsal root ganglia (DRG) and spinal cord. BDNF synthesis increases in response to nerve growth factor (NGF) in trkA-expressing small and medium-sized DRG neurons after inflammation. Previously we demonstrated differential activation of multiple BDNF promoters in the DRG following peripheral nerve injury and inflammation. Using reporter constructs containing individual promoter regions, we investigated the effect of NGF on the multiple BDNF promoters, and the signaling pathway by which NGF activates these promoters in PC12 cells. Although all the promoters were activated 2.4-7.1-fold by NGF treatment, promoter IV gave the greatest induction. The p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294003, protein kinase A (PKA) inhibitor, H89, and protein kinase C (PKC) inhibitor, chelerythrine, had no effect on activation of promoter IV by NGF. However, activation was completely abolished by the MAPK kinase (MEK) inhibitors, U0126 and PD98059. In addition, these inhibitors blocked NGF-induced phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2. Taken together, these results suggest that the ERK1/2 pathway activates BDNF promoter IV in response to NGF independently of NGF-activated signaling pathways involving PKA and PKC.

• Environmental Mutagens and Carcinogens
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• v.25 no.1
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• pp.19-24
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• 2005

The Swedish double mutation (KM670/671NL) of amyloid precursor protein (Swe-APP) is associated with early-onset familial Alzheimer's disease (FAD) and increases amyloid beta peptide production. Although APP/A/3 mediated neurotoxicity is observed both in vitro and in vivo, the relationship between mutant APP expression, A/3 production, and neuronal death observed in the brains of FAD patients remains to be elucidated. In this study, we investigated the mechanisms of Swe-APP-induced cell death in HEK293 and NGF-differentiated PC 12 cells. We found that the expression of Swe-APP induced cytochrome C relase, activation of caspase 3 in HEK 293 and NGF-differentiated PC 12 cells. We also show that the reactive oxygen species (ROS) was detected in Swe-APP expressing HEK 293 cells and NGF-differentiated PC 12 cells and that pretreatment with vitamine E attenuated the cellular death, cytochrome C release induced by Swe-APP expression, indicating the involvement of free radical in these processes. These results suggest one of possible apoptotic mechanisms of Swe-APP which could occur through cytochrome C release from mitochondria and this apoptosis inducing effects could be at least in part, due to ROS generation by Swe-APP expression.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.3
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• pp.145-163
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• 2003

Objectives : This study was performed to investigate the depigmentation effects of Aloe, Camellia sinensis and Mel. Methods : Inhibition of tyrosinase activity, melanin production & melanoma cell viability in cultured B16 melanoma cells, UV screen and cytoprotective effects on PC12 cells injured by hydrogen peroxide were measured. Results : Aloe has some inhibitory effects on tyrosinase activity, on the other hand Camellia sinensis and Mel do not have. They did not show any inhibitory effects on melanin production in melanoma cells and cytoprotective effects on PC12 cells injured by hydrogen peroxide. Aloe and Camellia sinensis have some inhibitory effects on UV screen. Conclusions : This study shows that Aloe and Camellia sinensis which were generally used for external application have some depigmentation effects. Following this, We should use them for whitening agents and the depigmentation effects of the other natural subjects which were generally used for external application should be examined.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.425-449
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• 1999

For the evaluation of the effect on SWS, experiments were made on hyperlipidemia induced by hypercholesterol diet, inhibitory reaction to human platelet aggregation, Pulmonary thrombosis induced by collagen and epinephrine, global cerebral ischemia induced by KCN, brain ischemia induced by MCA occlusion, cytotoxicity of PC12 cells induced by amyloid ${\beta}$ protein(25-35), and NO production in RAW cells stimulated by lipopolysaccharide. The results were obtained as follows : 1. In the experiment on hyperlipidemia, the level of serum total cholesterol, phospholipid, and LDL-cholesterol were significantly decreased while the level of triglyceride, VLDL-cholesterol, and HDL-cholesterol had no significant change. 2. In the experiment on inhibitory reaction to platelet aggregation, SWS inhibited platelet aggregation induced by ADP(36.05%), by collagen(20.4%), and by thrombin(0.6%). 3. In the experiment on pulmonary thrombosis induced by collagen and epinephrine, the protective effect was found(37%). 4. In the experiment on global cerebral ischemia, coma duration induced by KCN changed insignificantly. 5. In the experiment on MCA occlusion, the change of neurologic grades on hind limb was significant only after the operation. Besides brain ischemic area and edema ratio were significantly decreased. 6. In the experiment on cytotoxicity of PC 12 cells induced by amyloid ${\beta}$ protein, the significant protective effect was found as concentration increases. 7. In the experiment on NO production in RAW cells stimulated by lipopolysaccharide, NO was significantly decreased. According to the results, it is expected that SWS might be effective on hyperlipidemia and brain damage.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.2
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• pp.104-117
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• 2002

Objective : The aim of this study was to investigate the skin-whitening effect of Kakamseosiokyong-san Method : We investigated that the extracts of Kakamseosiokyong-san inhibit activity of tyrosinase, the enzyme which converts 3-(3,4-dihydroxyphenyl)alanine to dopachrom in the biosynthetic process of melanin. the UV absorbance of the extracts in the UV - A region and UV - B region was measured by UV scanning. the effect of extracts on cell viability and melanin production in cultured B16 mouse melanoma cells was measured, and cytoprotective effects of extracts on PC12 cells injured by hydrogen peroxide was measured by MTT assay Results: The extracts of Kakamseosiokyong-san inhibited activity of tyrosinase. The extracts not only showed inhibitory effects on melanin production in cultured B16 mouse melanoma cells, but also exhibited cytoprotective effects on PC12 cells injured by hydrogen peroxide, but did not showed an absorbance in the UV - A region and UV - B region. Conclusion: These results suggest that Kakamseosiokyong-san inhibit melanin biosynthesis which is involved in hyperpigmentation and could be used as a whitening agent for the skin.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.231-238
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• 2005

Neuronal apoptotic events, which result in cell death, are occurred in hypoxic/ischemic conditions. Estradiol is a female sex hormone with steroid structure known to provide neuroprotection through multiple mechanisms in the central nervous system. This study was aimed to investigate the signal transduction pathway of $CoCl_2$-induced neuronal cell death and the inhibitory effects of estradiol. Administration of $CoCl_2$ decreased cell viability in both a dose- and time-dependent manner in PC12 cells. $CoCl_2$-induced cell death produced genomic DNA fragmentation and morphologic changes such as cell shrinkage and condensed nuclei. It was found that $CoCl_2$-treated cells increased the reactive oxygen species (ROS) as well as caspase-8, -9 and -3 activities. However, pretreatment with estradiol before exposure to $CoCl_2$ prevented the reduction in cell viability reduction and attenuated DNA fragmentation and morphologic changes caused by $CoCl_2$. Furthermore, the $CoCl_2$-induced increases of ROS levels and caspases activities were attenuated by estradiol. Gene expression analysis revealed that estradiol blocked the underexpression of the Bcl-2 and ameliorated the increase in the release of cytochrome c from mitochondria into cytoplasm and Fas-ligand (Fas-L) upregulated by $CoCl_2$. These results suggest that $CoCl_2$ induce apoptosis in PC12 cells through both mitochondria- and death receptor-mediated cell death pathway. Estradiol was found to have a neuroprotective effect against $CoCl_2$-induced apoptosis through the inhibition of ROS production and by modulating apoptotic effectors associated with the mitochondria- and death-dependent pathway in PC12 cells.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.239-246
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• 2005

In the central nervous system, nitric oxide (NO) is associated with many pathological diseases such as brain ischemia, neurodegeneration and inflammation. The epigallocatechin gallate (EGCG), a major compound of green tea, is recognized as protective substance against neuronal diseases. This study is aimed to investigate the effect of EGCG on NO-induced cell death in PC12 cells. Administration of sodium nitroprusside (SNP), a NO donor, decreased cell viability in a dose- and time-dependent manner and induced genomic DNA fragmentation with cell shrinkage and chromatin condensation. EGCG diminished the decrement of cell viability and the formation of apoptotic morphologenic changes as well as DNA fragmentation by SNP. EGCG played as an antioxidant that attenuated the production of reactive oxygen species (ROS) by SNP. The cells treated with SNP showed downregulation of Bcl-2, but upregulation of Bax. EGCG ameliorated the altered expression of Bcl-2 and Bax by SNP. The release of cytochrome c from mitochondria into cytosol and expression of voltage -dependent anion channel (VDAC)1, a cytochrome c releasing channel in mitochondria, were increased in SNP-treated cells, whereas were attenuated by EGCG. The enhancement of caspase-9, preceding mitochondria-dependent pathway, caspase-8 and death receptor-dependent pathway, as well as caspase-3 activities were suppressed by EGCG. SNP upragulated Fas and Fas-L, which are death receptor assembly, whereas EGCG ameliorated the expression of Fas enhanced by SNP. These results demonstrated that EGCG has a protective effect against SNP-induced apoptosis in PC12 cells, through scavenging ROS and regulating the mitocondria- and death receptor-mediated signal pathway. The present study suggest that EGCG might be a natural neuroprotective substance.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.179-193
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• 2008

Objective: The antioxidant and anti-Alzheimer effects of Semen Ziziphi Spinosae (SZS) water extract against the amyloid beta peptide (1-42) or H202-induced oxidative damage and cell death were investigated in rat pheochromocytoma line PC 12. Methods: The cells were incubated with SZS water extract and oxidative damage-inducing materials, amyloid beta peptide (1-42) or H2O2 for 24 h. The cellular viability was assessed by WST-1 assay, cytotoxic damage by LDH activity assay, oxidative damages of cells by fluorescence spectrophotometric method, and apoptosis by TUNEL staining assay. Results and Conclusions: 1. Preincubation of the cells with SZS water extract prior to amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) exposure elevated the cell survival close to the control and decreased the level of LDH activity and the fluorescence from the cell homogenates and TUNEL staining of the cells, compared to only amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) treated conditions. 2. Our study suggests that Semen Ziziphi Spinosae (SZS) water extract has protective effects against amyloid beta peptide (1-42) or H2O2-induced cell toxicity through the antioxidation mechanism, which might be beneficial for the treatment of Alzheimer's disease.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.29-40
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• 2008

Objectives : It has been reported that Sophorae Subprostratae Radix (SSR) has a neuroprotective effect on cerebral ischemia in animals. In the present study, the authors investigated the neuroprotective effect of SSR on glutamate excitotoxicity. Glutamate excitotoxicity was induced by using NMDA, AMPA, and KA in PC12 cells and in organotypic hippocampal slice cultures. Methods :Methanolic extract of SSR was added at 0.5, 5, and 50 ${\mu}$g/ml to culture media for 24 hours. The effects of SSR were evaluated by measuring of cell viability, PI-stained neuronal cell death, TUNEL-positive cells, and MAP-2 immunoreactivity. Results : SSR increased PC12 cell viabilities significantly against AMPA-induced excitotoxicity, but not against NMDA-induced or KA-induced excitotoxicity. In organotypic hippocampal slice cultures damaged by NMDA-induced excitotoxicity, SSR attenuated neuronal cell death significantly in the CA1, CA3, and DG hippocampal regions and reduced TUNEL-positive cells significantly in CA1 and DG regions. In organotypic hippocampal slice cultures damaged by AMPA-induced excitotoxicity, SSR attenuated neuronal cell death and reduced TUNEL-positive cell numbers significantly in the CA1 and DG regions. In organotypic hippocampal slice cultures damaged by KA-induced excitotoxicity, SSR attenuated neuronal cell death significantly in CA3, but did not reduce TUNEL-positive cell numbers in CA1, CA3 or DG. In organotypic hippocampal slice cultures damaged by NMDA-induced excitotoxicity, SSR attenuated pyramidal neuron neurite retraction and degeneration in CA1. Conclusions : These results suggest that the neuroprotective effects of SSR are related to antagonistic effects on the NMDA and AMPA receptors of neuronal cells damaged by excitotoxicity and ischemia.