• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.329-335
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• 2006

This study was aimed to investigate the nitric oxide (NO)-induced cytotoxic mechanism in PC12 cells. Sodium nitroprusside (SNP), an NO donor, decreased the viability of PC12 cells in dose-and time-dependent manners. SNP enhanced the production of reactive oxygen species (ROS), and gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. Expression of Bax was not affected, whereas Bcl-2 was downregulated in SNP-treated PC12 cells. SNP augmented the release of cytochrome c from mitochondria into cytosol and enhanced caspase -8, -9, and -3 activities. SNP upregulated both Fas and Fas-L, which are known to be components of death receptor assembly. These results suggest that NO induces apoptosis of PC12 cells through both mitochondria-and death receptor-mediated pathways mediated by ROS and Bcl-2 family.

• The Journal of Korean Medicine
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• v.32 no.1
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• pp.109-120
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• 2011

Objectives: The aim of this investigation was to evaluate the efficacy of KHchunggan-tang aqueous extract on the experimental nonalcoholic fatty liver disease(NAFLD) induced by palmitate. Materials and Methods: To generate a cellular model of NAFLD, we used HepG2 cells, a human hepatoma cell line, treated with 0.5 mM palmitate. By this cellular model, effects of KHchunggan-tang aqueous extract were evaluated. Intracellular lipid accumulation, free radical formation, and apoptosis were detected by Nile red staining, 2',7'-dichloroflourescin diacetate(H2DCF-DA), and 4',6-diamidino-2-phenylindole(DAPI)/propidium iodide(PI) staining, respectively. Some proteins related with NAFLD were determined by western blot. Results: Typical pathological features of NAFLD occurred in the cellular model. Palmitate increased the levels of intracellular lipid vacuoles, decreased cell viability, and increased apoptosis. Palmitate increased free radical formation and lipid peroxidation, too. However, KHchunggan-tang aqueous extract reduced palmitate-induced pathologic features, i.e. steatosis, free radical formation, and apoptosis. In addition, KHchunggan-tang aqueous extract suppressed palmitate-activated c-Jun N-terminal kinase(JNK) signaling, and SP600125, a JNK inhibitor, significantly reversed the palmitate-induced pathologic changes as KHchunggan-tang aqueous extract. It means that the signaling pathway other than JNK can be involved in the KHchunggan-tang mediated cellular protection of palmitate-treated Hep G2 cells. Conclusions: These results suggest that KHchunggan-tang aqueous extract has hepatoprotective effects on NAFLD with combined properties in cellular steatosis, ROS production, and cytoprotection, and thus may have valuable clinical applications for treatment of this chronic liver disease.

• Herbal Formula Science
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• v.29 no.4
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• pp.167-179
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• 2021

Objectives : Oxidative stress is a important cause of liver disease, and regulation of oxidative stress is essential to maintain the normal metabolic function of the liver. Until a recent date, there has been no studies on the hepatoprotective effect of Ikwiseungyang-tang (IWSYT). Therefore, this study aims to demonstrate the hepatoprotective effect of IWSYT and its related molecular mechanisms on arachidonic acid (AA) + iron induced oxidative stress model in HepG2 cells. Methods : To determine the cytoprotective effect of IWSYT against AA + iron-induced oxidative stress, cell viability, apoptosis-related proteins, intracellular reactive oxygen species (ROS), GSH, and mitochondrial membrane potential (MMP) were measured. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation was analyzed by immunoblot analysis. In addition, Nrf2 transcription activation through ARE binding was measured by reporter gene assays, and the expression of the Nrf2 target antioxidant genes were confirmed by immunoblot analysis. Results : IWSYT increased cell viability from cell death induced by AA + Iron, and inhibited apoptosis by regulating apoptosis-related proteins. Furthermore, IWSYT protected cells by inhibiting intracellular ROS production, GSH depletion, and MMP degradation. Nrf2 activation was increased by IWSYT, and Nrf2 target genes were activated by IWSYT too. Conclusions : These results suggest that IWSYT can protect hepatocytes from oxidative stress through Nrf2 activation and can be potentially applied in the prevention and treatment of liver damage.

• Herbal Formula Science
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• v.31 no.2
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• pp.111-124
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• 2023

Objectives : Oxidative stress is an important cause of many diseases including liver injury. Therefore, adequate regulation of oxidative stress plays a pivotal role in maintaining liver function. Until recently, there has been no studies on the hepatoprotective effect of Samchulgeonbi-tang (SCGBT). Therefore, the hepatoprotective effect of SCGBT was investigated in HepG2 cells. In this study, oxidative stress was induced by arachidonic acid (AA) and iron. Methods : To analyze the hepatoprotective effects of SCGBT against oxidative stress induced by AA + iron, the cell viability, apoptosis-related proteins and intracellular ROS, glutathione (GSH), and mitochondrial membrane permeability (MMP) were measured. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) transcription activation and expressions of Nrf2 target gene were analyzed through immunoblot analysis. Results : SCGBT increased the cell viability from AA + iron - induced cell death and inhibited apoptosis by regulating apoptosis related proteins. SCGBT protected cells by inhibiting ROS production, GSH depletion, and MMP degradation against AA + iron induced oxidative stress. Furthermore, Nrf2 activation was increased by SCGBT, and the Nrf2 target genes were also activated by SCGBT. Conclusions : These results suggest that the SCGBT has a hepatocyte protection effect and antioxidant effect from AA + iron induced oxidative stress.

• Biomolecules & Therapeutics
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• v.26 no.2
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• pp.121-129
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• 2018

Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and apoptosis play critical roles in the pathogenesis of atherosclerosis. Thioredoxin-1 (Trx) is an antioxidant that potently protects various cells from oxidative stress-induced cell death. However, the protective effect of Trx on ox-LDL-induced macrophage foam cell formation and apoptosis has not been studied. This study aims to investigate the effect of recombinant human Trx (rhTrx) on ox-LDL-stimulated RAW264.7 macrophages and elucidate the possible mechanisms. RhTrx significantly inhibited ox-LDL-induced cholesterol accumulation and apoptosis in RAW264.7 macrophages. RhTrx also suppressed the ox-LDL-induced overproduction of lectin-like oxidized LDL receptor (LOX-1), Bax and activated caspase-3, but it increased the expression of Bcl-2. In addition, rhTrx markedly inhibited the ox-LDL-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38 mitogen-activated protein kinases (MAPK). Furthermore, anisomycin (a p38 MAPK activator) abolished the protective effect of rhTrx on ox-LDL-stimulated RAW264.7 cells, and SB203580 (a p38 MAPK inhibitor) exerted a similar effect as rhTrx. Collectively, these findings indicate that rhTrx suppresses ox-LDL-stimulated foam cell formation and macrophage apoptosis by inhibiting ROS generation, p38 MAPK activation and LOX-1 expression. Therefore, we propose that rhTrx has therapeutic potential in the prevention and treatment of atherosclerosis.

• Biomedical Science Letters
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• v.19 no.2
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• pp.118-123
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• 2013

Tumor necrosis factor-alpha (TNF-${\alpha}$) is a proinflammatory cytokine that mediates the inflammatory response and immune functions, and modulates the proliferation, differentiation and cell death of cancer cells. The differential functions of TNF-${\alpha}$ in various human cells due to the formation of different stimulating pathway upon the binding of TNF-${\alpha}$ to its receptors. In the present study, we examined the different effects of TNF-${\alpha}$ on the survival and apoptosis between normal granulocytes and human myeloid leukemia HL-60 cells. Although TNF-${\alpha}$ did not affect on the constitutive apoptosis of granulocytes, TNF-${\alpha}$ strongly induced the apoptosis of HL-60 cells in a dose- and a time-dependent manner. TNF-${\alpha}$-induced apoptosis was occurred via the activation of caspase 8, caspase 9 and caspase 3/7 and the induction of ROS production in HL-60 cells. Also, BAY-11-7085, a NF-${\kappa}B$ inhibitor, blocked the TNF-${\alpha}$-induced apoptosis in HL-60 cells. NF-${\kappa}B$ may be involved in TNF-${\alpha}$-induced apoptotic signaling pathway in HL-60 cells. These results suggest that TNF-${\alpha}$ activates apoptotic pathways and its process depends on cell type and many cellular factors. A better understanding of the differential effect of TNF-${\alpha}$ on cell apoptosis and survival may provide important information that can be used to elucidate the specific inhibitory effect of TNF-${\alpha}$ on the cancer dis.

• Journal of Korean Neurosurgical Society
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• v.38 no.6
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• pp.456-464
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• 2005

Objective : The authors investigated whether rotenone induces cellular death also in non-dopaminergic neurons and high concentration of potassium ion can show protective effect for non-dopaminergic neuron in case of rotenone-induced cytotoxicity. Methods : Neuro 2A cells was treated with rotenone, and their survival as well as cell death mechanism was estimated using 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium[MTT] assay, Lactate dehydrogenase[LDH] release assay, fluorescence microscopy, and agarose gel electrophoresis. The changes in rotenone-treated cells was also studied after co-treatment of 50mM KCl. And the protective effect of KCl was evaluated by mitochondrial membrane potential assay and compared with the effects of various antioxidants. Results : Neuro 2A cells treated with rotenone underwent apoptotic death showing chromosome condensation and fragmentation as well as DNA laddering. Co-incubation of neuro 2A cells with 50mM KCl prevented it from the cytotoxicity induced by rotenone. Intracellular accumulation of reactive oxygen species[ROS] resulting by rotenone were significantly reduced by 50mM KCl. Potassium exhibited significantly similar potency compared to the antioxidants. Conclusion : The present findings showed that potassium attenuated rotenone-induced cytotoxicity, intracellular accumulation of ROS, and fragmentation of DNA in Neuro 2A cells. These findings suggest the therapeutic potential of potassium ion in neuronal apoptosis, but the practical application of high concentration of potassium ion remains to be settled.

• Biomolecules & Therapeutics
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• v.28 no.2
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• pp.184-194
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• 2020

Histone deacetylase (HDAC) inhibitors represent a novel class of anticancer agents, which can be used to inhibit cell proliferation and induce apoptosis in several types of cancer cells. In this study, we investigated the anticancer activity of MHY4381, a newly synthesized HDAC inhibitor, against human prostate cancer cell lines and compared its efficacy with that of suberoylanilide hydroxamic acid (SAHA), a well-known HDAC inhibitor. We assessed cell viability, apoptosis, cell cycle regulation, and other biological effects in the prostate cancer cells. We also evaluated a possible mechanism of MHY4381 on the apoptotic cell death pathway. The IC₅₀ value of MHY4381 was lower in DU145 cells (IC₅₀=0.31 µM) than in LNCaP (IC₅₀=0.85 µM) and PC-3 cells (IC₅₀=5.23 µM). In addition, the IC₅₀ values of MHY4381 measured in this assay were significantly lower than those of SAHA against prostate cancer cell lines. MHY4381 increased the levels of acetylated histones H3 and H4 and reduced the expression of HDAC proteins in the prostate cancer cell lines. MHY4381 increased G2/M phase arrest in DU145 cells, and G1 arrest in LNCaP cells. It also activated reactive oxygen species (ROS) generation, which induced apoptosis in the DU145 and LNCaP cells by increasing the ratio of Bax/Bcl-2 and releasing cytochrome c into the cytoplasm. Our results indicated that MHY4381 preferentially results in antitumor effects in DU145 and LNCaP cells via mitochondria-mediated apoptosis and ROS-facilitated cell death pathway, and therefore can be used as a promising prostate cancer therapeutic.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.76-76
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• 2020

Stachys sieboldii Miq. (chinese artichoke), which has been extensively used in oriental traditional medicine to treat of ischemic stroke; however, the role of Stachys sieboldii Miq. (SSM) in cerebral ischemia/reperfusion (I/R) injury is not yet fully understood. In the current study, the neuroblastoma cell line (SH-SY5Y) were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) to simulate I/R injury in vitro model. The results showed that SSM improved OGD/R-induced inhibitory effect on cell viability of SH-SY5Y Cells. SSM displayed anti-oxidative activity as proved by the decreased levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in OGD/R-induced SH-SY5Y Cells. In addition, cell apoptosis was markedly decreased after SSM treatment in OGD/R-induced SH-SY5Y Cells. The up-regulation of Bcl-2 and down-regulation of Bax, thus reducing the Bax/Bcl-2 ratio that in turn protected the activation of caspase-9 and -3, and inhibition of poly (ADP-ribose) polymerase cleavage, which was associated with the blocking of cytochrome c release to the cytoplasm. Collectively, SSM protected human neuroblastoma SH-SY5Y cells from OGD/R-induced injury via preventing mitochondrial-dependent pathway through scavenging excessive ROS, suggesting that SSM might be a potential agent for the ischemic stroke therapy.

• Korean Circulation Journal
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• v.52 no.9
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• pp.680-696
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• 2022

Background and Objectives: Circular RNAs were known to play vital role in myocardial ischemia reperfusion injury (MIRI), while the role of CircZNF609 in MIRI remains unclear. This study was aimed to investigate the function of CircZNF609 in MIRI. Methods: Hypoxia/reoxygenation (H/R) model was established to mimic MIRI in vitro. Quantitative polymerase chain reaction was performed to evaluate gene transcripts. Cellular localization of CircZNF609 and miR-214-3p were visualized by fluorescence in situ hybridization. Cell proliferation was determined by CCK-8. TUNEL assay and flow cytometry were applied to detect apoptosis. Lactate dehydrogenase was determined by commercial kit. ROS was detected by DCFH-DA probe. Direct interaction of indicated molecules was determined by RIP and dual luciferase assays. Western blot was used to quantify protein levels. In vivo model was established to further test the function of CircZNF609 in MIRI. Results: CircZNF609 was upregulated in H/R model. Inhibition of CircZNF609 alleviated H/R induced apoptosis, ROS generation, restored cell proliferation in cardiomyocytes and human umbilical vein endothelial cells. Mechanically, CircZNF609 directly sponged miR-214-3p to release PTGS2 expression. Functional rescue experiments showed that miR-214-3p/PTGS2 axis was involved in the function of circZNG609 in H/R model. Furthermore, data in mouse model revealed that knockdown of CircZNF609 significantly reduced the area of myocardial infarction and decreased myocardial cell apoptosis. Conclusions: CircZNF609 aggravated the progression of MIRI via targeting miR-214-3p/PTGS2 axis, which suggested CircZNF609 might act as a vital modulator in MIRI.