• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.888-894
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• 2009

It has been reported that silibinin, a natural polyphenolic flavonoid, induces cell death in various cancer cell types. However, the underlying mechanisms by which silibinin induces apoptosis in human glioma cells are poorly understood. The present study was therefore undertaken to examine the effect of silibinin on glioma cell apoptosis and to determine its underlying mechanism in human glioma cells. Apoptosis was estimated by FACS analysis. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (${\Psi}m$) were measured using fluorescence dyes DCFH-DA and $DiOC_6$(3), respectively. Cytochrome c release from mitochondria and caspase-3 activation were estimated by Western blot analysis using specific antibodies. Exposure of cells to 30 mM silibinin induced apoptosis starting at 6 h, with increasing effects after 12-48h in a time-dependent manner. Silibinin caused ROS generation and disruption of ym, which were associated with the silibinin-induced apoptosis. The silibinin-induced ROS generation and disruption in ym were prevented by inhibitors of mitochondrial electron transport chain. The hydrogen peroxide scavenger catalase blocked ROS generation and apoptosis induced by silibinin. Silibinin induced cytochrome c release into cytosolic fraction and its effect was prevented by catalase and cyclosporine A. Silibinin treatment caused caspase-3 activation, which was inhibited by DVED-CHO and cyclosporine A. Pretreatment of caspase inhibitors also protected against the silibinin-induced apoptosis. These findings indicate that ROS generation plays a critical role in the initiation of the silibinin-induced apoptotic cascade by mediation of the mitochondrial apoptotic pathway including the disruption of ${\Psi}m$, cytochrome c release, and caspase-3 activation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3239-3245
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• 2012

Gliomas are a group of heterogeneous primary central nervous system tumors. Hyperthermia has proven to be a potential therapeutic tool for cancers in the clinic. However, the molecular mechanisms of hyperthermia remain unclear. The objective of this study was to investigate the effects of hyperthermia on the invasiveness in C6 glioma cells and related molecular pathways. Here our data show hyperthermia stimulated the release of tumor necrosis factor-alpha (TNF-${\alpha}$) and decreased C6 glioma cell migration and invasive capability at 30, 60, 120 and 180 min; with increased spontaneous apoptosis in C6 glioma cells at 120 min. We also found mitogen-activated protein kinase (P38 MAPK) protein expression to be increased and nuclear factor-kappa B (NF-${\kappa}B$) protein expression decreased. Based on the results, we conclude that hyperthermia alone reduced invasion of C6 glioma cells through stimulating TNF-${\alpha}$ signaling to activate apoptosis, enhancing P38 MAPK expression and inhibiting the NF-${\kappa}B$ pathway, a first report in C6 rat glioma cells.

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.242-245
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• 2009

In order to investigate the cytotoxic effect of hexavalent chromium ($Cr0_3$) and the protective effect of Nelumbo nucifera GAERTN (NNG) extract, cultured cerebral neuroglial cells (C6 glioma cells) were treated with $4{\sim}55{\mu}M$ concentrations of $Cr0_3$ for 48 hours. Cell viability was measured by XTT assay. The superoxide dismutase (SOD)-like activity for the antioxidant effect was also examined on the extract of NNG stamen. In this study, $Cr0_3$ significantly decreased cell viability dose-dependently. The cytotoxicities of $XTT_{90}$ and $XTT_{50}$ determined with $10{\mu}M$ and $55{\mu}M$ of $Cr0_3$, respectively, showed that the $Cr0_3$ had highly toxic effect on cultured C6 glioma cells by the cytotoxic criteria. In the protective effect of NNG extract, the cell viability was significantly increased by the treatment of NNG extract, and NNG extract increased SOD-like activity. From these results, it is suggested that $Cr0_3$ showed highly toxic effect on cultured C6 glioma cell s and NNG extract was very effective in the protection of $Cr0_3$-mediated cytotoxicity by antioxidative effect in these cultures.

• Journal of Life Science
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• v.27 no.3
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• pp.267-274
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• 2017

The patient with end-stage renal disease show several nervous complications. The factors contributing to the nervous complications are still incompletely characterized. Cyanate, known as one of the uremic toxins, is derived spontaneously from urea. To investigate the mechanism of cyanate-induced effect on C6 glioma cells, the glioma cells were treated with 0, 1, 5, 10, 20 and 40 mM cyanate. There was a dose-dependent decrease in cell viability and the decreased number of cell was observed in glioma cells by treatment with cyanate. Western blot showed the down- regulation of procaspase-3, which means up-regulation of caspase-3, and the up-regulation of caspase-8, but the down-regulation by cyanate. In addition, cDNA microarray showed 934 down-regulated genes and 165 up-regulated genes on 1,099 genes in cyanate treated group. Treatment with cyanate led to 16 down-regulated genes and 6 up-regulated genes on apoptosis category, and especially heat shock 70 kD protein 1A gene on the category of apoptosis was significantly up-regulated. These results suggest that cyanate can induce apoptosis through caspase-8 and caspase-3 in glioma cells and decrease of gene expression including apoptosis category in glioma cells. These effects of cyanate may play a role in the nervous complications of patient with end-stage renal disease.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.2
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• pp.75-81
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• 2011

To clarify the oxidative stress of reactive oxygen species (ROS) and the effect of Chrysanthemum morifolium L. (CM) flower extract on the cultured neuroglial cells (C6 glioma) damaged by ROS, cell adhesion effect was measured by colorimetric assay after cultured C6 glioma cells were treated with various concentrations of glucose oxidase (GO) for 5 hours. For the antioxidative effect of CM flower extract, cell adhesion activity (CAA), superoxide dismutase (SOD)-like activity and lactate dehydrogenase (LDH) activity were assessed against GO-induced cytotoxicity on same cultures. In this study, GO remarkably decreased CAA dose-dependently, and the $XTT_{90}$ and $XTT_{50}$ values were measured at 15 mU/mL and 50 mU/mL following the treatment of C6 glioma cells with 5~60 mU/mL of GO. The CM flower extract significantly increased cell adhesion activity damaged by GO-induced cytotoxicity, and it also showed the SOD-like activity and the decrease of LDH activity. From these results, it is suggested that GO was cytotoxic on cultured C6 glioma cells, and CM flower extract showed antioxidative effects as shown by the increased CAA, SOD-like activity and the decrease of LDH activity on GO-induced cytotoxicity on the same cultures.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4793-4799
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• 2012

Hypoxia is commonly featured during glioma growth and plays an important role in the processes underlying tumor progression to increasing malignancy. Here we compared the gene expression profiles of rat C6 malignant glioma cells under normoxic and hypoxic conditions by cDNA microarray analysis. Compared to normoxic culture conditions, 180 genes were up-regulated and 67 genes were down-regulated under hypoxia mimicked by $CoCl_2$ treatment. These differentially expressed genes were involved in mutiple biological functions including development and differentiation, immune and stress response, metabolic process, and cellular physiological response. It was found that hypoxia significantly regulated genes involved in regulation of glycolysis and cell differentiation, as well as intracellular signalling pathways related to Notch and focal adhesion, which are closely associated with tumor malignant growth. These results should facilitate investigation of the role of hypoxia in the glioma development and exploration of therapeutic targets for inhibition of glioma growth.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.375-382
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• 2003

Effects of ginsenosides on nitric oxide (NO) production induced by lipopolysaccharide plus TNF-$\alpha$ (LNT) were examined in C6 rat glioma cells. Among several ginsenosides, ginsenoside Rd showed a complete inhibition against LNT-induced NO production. Ginsenoside Rd attenuated LNT-induced increased phosphorylation of ERK. Among several immediate early gene products, only Jun Band Fra-1 protein levels were increased by LNT, and ginsenoside Rd attenuated Jun Band Fra-1 protein levels induced by LNT. Furthermore, LNT increased AP-1 DNA binding activities, which were partially inhibited by ginsenoside Rd. Our results suggest that ginsenoside Rd exerts an inhibitory action against NO production via blocking phosphorylation of ERK, in turn, suppressing immediate early gene products such as Jun Band Fra-1 in C6 glioma cells.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.216.1-216.1
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• 2003

Neuronal apoptosis may contribute to the pathological neuronal loss in certain disease states such as neurodegenerative diseases. Staurosporine (ST), a nonselective protein kinase inhibitor, has been shown to induce apoptosis in a variety of cells including nerve cell lines. In this study, we investigated the neuroprotective effect of sauchinone, which is a unique lignan from Sauchinone Chinensis, on ST-induced apoptosis in C6 rat glioma cells. (omitted)

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.401-409
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• 2010

This study was designed to investigate the effects of BojungIkkiTang-Gamybang freeze dried powder (BITG) on proliferauion, protective of cell death induced by chemicals such as paraquat, hydrogen peroxide etc and anti-oxidative effects in C6 glioma cells. In our results, BITC accelerated proliferation rates of C6 cells in vitro. In addition, protective effects on cell death induced by paraquat and hydrogen peroxide. And, BITC did not have effects on SOD and total glutathione activities, but decresed malone dialdehyde activity. In conclusion, these results suggest the possibility of BojungIkkiTang-Gamybang to protect brain cell or neuronal cell from damage induced by oxidative stress. And also suggest that related mechanisms are involved in malone dialdehyde activity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.296-302
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• 2002

Bohyulmyunyuk-dan is an Oriental herbal formulation to enhance the general body conditions as well as immune response against both endogenous and exogenous harmful challenges. This study was designed to investigate the effect of Bohyulmyunyuk-dan on the cisplatin-induced toxicity of primary rat astrocytes and C6 glioma cells. After trestment of astrocytes and C6 glioma cells with cisplatin, MTT assay was carried out to measure cytotoxicity of brain cells. To explore the mechanism of cytotoxicity, astrocytes were treated with Bohyulmyunyuk-dan and followed by the addition of cisplatin. Then, the protective effects of Bohyulmyunyuk-dan were investigated in apoptosis signaling pathway. The results were obtained as follows ; Bohyulmyunyuk-dan protected the death of astrocytes by cisplatin, which decreased the viability of astrocytes and C6 glioma cells in a time- and dose-dependent manner. Bohyulmyunyuk-dan protected the apoptotic death of astrocytes from cisplatin induced cell apoptosis. Bohyulmyunyuk-dan inhitited the activation of caspase-3 and -9 protease in astrocytes by cisplatin. Bohyulmyunyuk-dan inhibited the deavage of PARP in astrocytes by cisplatin. According to above results, Bohyulmyunyuk-dan may prevent brain cells from cytotoxicity induced cell apoptosis induced by chemotherapeatic agents induding displatin.