• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.353-361
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• 2011

In this study, cyanidin-3-glucoside (C3G) fraction extracted from the mulberry fruit (Morus alba L.) was investigated for its neuroprotective effects against oxygen-glucose deprivation (OGD) and glutamate-induced cell death in rat primary cortical neurons. Cell membrane damage and mitochondrial function were assessed by LDH release and MTT reduction assays, respectively. A time-course study of OGD-induced cell death of primary cortical neurons at 7 days in vitro (DIV) indicated that neuronal death was OGD duration-dependent. It was also demonstrated that OGD for 3.5 h resulted in approximately 50% cell death, as determined by the LDH release assay. Treatments with mulberry C3G fraction prevented membrane damage and preserved the mitochondrial function of the primary cortical neurons exposed to OGD for 3.5 h in a concentration-dependent manner. Glutamate-induced cell death was more pronounced in DIV-9 and DIV-11 cells than that in DIV-7 neurons, and an application of $50{\mu}M$ glutamate was shown to induce approximately 40% cell death in DIV-9 neurons. Interestingly, treatment with mulberry C3G fraction did not provide a protective effect against glutamate-induced cell death in primary cortical neurons. On the other hand, treatment with mulberry C3G fraction maintained the mitochondrial membrane potential (MMP) in primary cortical neurons exposed to OGD as assessed by the intensity of rhodamine-123 fluorescence. These results therefore suggest that the neuroprotective effects of mulberry C3G fraction are mediated by the maintenance of the MMP and mitochondrial function but not by attenuating glutamate-induced excitotoxicity in rat primary cortical neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.1
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• pp.71-80
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• 2018

In patients with epilepsy, depression is a common comorbidity but difficult to be treated because many antidepressants cause pro-convulsive effects. Thus, it is important to identify the risk of seizures associated with antidepressants. To determine whether paroxetine, a very potent selective serotonin reuptake inhibitor (SSRI), interacts with ion channels that modulate neuronal excitability, we examined the effects of paroxetine on Kv3.1 potassium channels, which contribute to high-frequency firing of interneurons, using the whole-cell patch-clamp technique. Kv3.1 channels were cloned from rat neurons and expressed in Chinese hamster ovary cells. Paroxetine reversibly reduced the amplitude of Kv3.1 current, with an $IC_{50}$ value of $9.43{\mu}M$ and a Hill coefficient of 1.43, and also accelerated the decay of Kv3.1 current. The paroxetine-induced inhibition of Kv3.1 channels was voltage-dependent even when the channels were fully open. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for the paroxetine effect were $4.5{\mu}M^{-1}s^{-1}$ and $35.8s^{-1}$, respectively, yielding a calculated $K_D$ value of $7.9{\mu}M$. The analyses of Kv3.1 tail current indicated that paroxetine did not affect ion selectivity and slowed its deactivation time course, resulting in a tail crossover phenomenon. Paroxetine inhibited Kv3.1 channels in a use-dependent manner. Taken together, these results suggest that paroxetine blocks the open state of Kv3.1 channels. Given the role of Kv3.1 in fast spiking of interneurons, our data imply that the blockade of Kv3.1 by paroxetine might elevate epileptic activity of neural networks by interfering with repetitive firing of inhibitory neurons.

• BMB Reports
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• v.44 no.7
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• pp.462-467
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• 2011

Up-regulation of selected matrix metalloproteinases (MMPs) such as MMP-9 contributes to inflammatory processes during the development of various skin diseases, such as atopic dermatitis. In this study, we examined the effect of a cell-permeable superoxide dismutase (Tat-SOD) on TNF-${\alpha}$-induced MMP-9 expression in human keratinocyte cells (HaCaT). When Tat-SOD was added to the culture medium of HaCaT cells, it rapidly entered the cells in dose- and time-dependent manners. Tat-SOD decreased TNF-${\alpha}$-induced reactive oxygen species (ROS) generation. Tat-SOD also inhibited TNF-${\alpha}$-induced NF-${\kappa}B$ DNA binding activity. Treatment of HaCaT cells with Tat-SOD significantly inhibited TNF-${\alpha}$-induced mRNA and protein expression of MMP-9, as measured by RT-PCR and Western blot analysis. In addition, Tat-SOD suppressed TNF-${\alpha}$-induced gelatinolytic activity of MMP-9. Taken together, our results indicate that Tat-SOD can suppress TNF-${\alpha}$-induced MMP-9 expression via ROS-NF-${\kappa}B$-dependent mechanisms in keratinocytes, and therefore can be used as an immunomodulatory agent against inflammatory skin diseases related to oxidative stress.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1657-1662
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• 2012

Fucosyltransferase IV (FUT4) has been implicated in cell adhesion, motility, and tumor progression in human epidermoid carcinoma A431 cells. We previously reported that it promotes cell proliferation through the ERK/MAPK and PI3K/Akt signaling pathways; however, the molecular mechanisms underlying FUT4-induced cell invasion remain unknown. In this study we determined the effect of FUT4 on expression of matrix metalloproteinase (MMP)-12 induced by EGF in A431 cells. Treatment with EGF resulted in an alteration of cell morphology and induced an increase in the expression of MMP-12. EGF induced nuclear translocation of nuclear factor kB (NF-${\kappa}B$) and resulted in phosphorylation of $IkB{\alpha}$ in a time-dependent manner. In addition, ERK1/2 and p38 MAPK were shown to play a crucial role in mediating EGF-induced NF-${\kappa}B$ translocation and phosphorylation of $I{\kappa}B{\alpha}$ when treated with the MAPK inhibitors, PD98059 and SB203580, which resulted in increased MMP-12 expression. Importantly, we showed that FUT4 up-regulated EGF-induced MMP-12 expression by promoting the phosphorylation of ERK1/2 and p38 MAPK, thereby inducing phosphorylation/degradation of $I{\kappa}B{\alpha}$, NF-${\kappa}B$ activation. Base on our data, we propose that FUT4 up-regulates expression of MMP-12 via a MAPK-NF-${\kappa}B$-dependent mechanism.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7995-8001
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• 2014

Interferon-gamma (IFN-${\gamma}$) has been used to treat various malignant tumors. However, the molecular mechanisms underlying the direct anti-proliferative activity of IFN-${\gamma}$ are poorly understood. In the present study, we examined the in vitro antitumor activity of IFN-${\gamma}$ on two human non-small-cell lung carcinoma (NSCLC) cell lines, H322M and H226. Our findings indicated that IFN-${\gamma}$ treatment caused a time-dependent reduction in cell viability and induced apoptosis through a FADD-mediated caspase-8/tBid/mitochondria-dependent pathway in both cell lines. Notably, we also postulated that IFN-${\gamma}$ increased indoleamine 2,3-dioxygenase (IDO) expression and enzymatic activity in H322M and H226 cells. In addition, inhibition of IDO activity by the IDO inhibitor 1-MT or tryptophan significantly reduced IFN-${\gamma}$-induced apoptosis and death receptor 5 (DR5) expression, which suggests that IDO enzymatic activity plays an important role in the anti-NSCLC cancer effect of IFN-${\gamma}$. These results provide new mechanistic insights into interferon-${\gamma}$ antitumor activity and further support IFN-${\gamma}$ as a potential therapeutic adjuvant for the treatment of NCSLC.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.52-60
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• 2007

Plant can detoxify the effect of the volatile organic compounds (VOC) such as formaldehyde and toluene, however, mechanisms of VOC detoxification are largely unknown in plant system. This study was performed to investigate phenotypic changes of Arabidopsis seedlings upon treatment of either formalin or toluene. Formalin treatment up to twenty four hours didn't cause any significant phenotypic damages on the leaf surface of 27 DAG Arabidopsis seedlings. However, the protein profile of formalin-treated seedlings was significantly different from that of mock control. Using automated electrophoresis system, the molecular weight of each formaldehyde-responsive protein (FRP) was predicted and its formaldehyde-dependent expression was confirmed at transcription level by quantitative real-time RT-PCR analysis. Four FRPs isolated in this study are the novel proteins with unknown functions but highly homologous to the stress-related proteins.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.1050-1054
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• 2005

Recently, arsenic compounds were considered as novel agents for treatment of acute promyelocytic leukemia and malignant tumors. However, it showed severe toxicity effect on normal tissue at the same time. In this study, to investigate the possible molecular mechanism (s) of arsenic compounds as candidate of anti-cancer drugs, we compared the abilities of two arsenic compounds, tetraarsenic oxide $(AS_4O_6)$ and arsenic trioxide (diarsenic oxide, $As_2O_3$), to induce cell growth inhibition as well as apoptosis induction in A549 human non-small cell lung cancer cells. Both $As_4O_6\;and\;As_2O_3$ treatment declined the cell growth and viability of A549 cells in a concentration-dependent manner, which was associated with induction of G1 arrest of the cell cycle and apoptotic cell death. However, $As_4O_6$ induced growth inhibition and apoptosis in A549 cells at much lower concentrations than $As_2O_3.\;As_4O_6$ down-regulated the levels of anti-apoptotic Bcl-2 protein, however, the levels of Bax, a pro-apoptotic protein, were up-regulated in a dose-dependent manner. In conclusion, $As_4O_6$ might be a new arsenic compound which may induce apoptosis in A549 cells by modulation the Bcl-2 family and deserves further evaluation.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.289-296
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• 2016

This study was executed to evaluate the immune activity, nitrite scavenging activity and ABTS radical scavenging activity against extracts of various concentration of ethanol solvent from Codonopsis lanceolata cultured at 6 local regions. The immune responses from both human T and B cell line was significantly enhanced in the cell growth compared to control while the cell growth was influenced at a certain period of culture. The results revealed that the cell growth of both human T and B cell was altered in a time dependent manner. The nitrite scavenging activity of ethanol extracts from various solvent concentration of C. lanceolata were affected by pH. At a pH of 1.2, the nitrite scavenging effect of all of the extracts tested observed higher than that of the other two pH ranges. There was no distinct detection of nitrite scavenging effects of the pH range 6.0. The ABTS radical scavenging activity was progressively increased in a dose-dependent manner, and the activity was the highest in 100% ethanol extract. The result from this investigation suggests that the extract of Codonopsis lanceolata could be an addition to basic medicine for immune modulation and natural food additives.

• YAKHAK HOEJI
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• v.49 no.6
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• pp.471-476
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• 2005

Rhus verniciflua Stokes (RVS) has been used as a food supplement and a traditional herbal medicine for a men's sexual enhancement. In this study, we prepared a flavonoid fraction (RWE) from a hot water extract of RVS and its influence on sexual behavior was studied in male rats which were orally administered varying doses of RWE for 2 weeks. All doses of RWE stimulated sexual behavior in male rats such as reducing mounting latency and enhancing mount frequencies. However, intermission numbers were not changed and none of group can observe the ejaculation during behavioral testing time 5 min. Testosterone levels were Increased about 0$\∼$53$\%$ and 92$\∼$164$\%$ by the treatment of RWE for 1 and 2 weeks, respectively. However, estrogen levels in male rats tended to decrease in a dose dependent manner of RWE. At the dose of RWE 200 mg/kg, estrogen level was reduced to 77.5$\%$ and 70.3$\%$ of control after 1 and 2 weeks treatment. These findings suggest that the Rhus flavonoid fraction can stimulate the androgen-dependent male sexual behavior and it can be applied to the material of functional food for enhancing the sexual function.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.67-78
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• 2020

Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.