• Biomolecules & Therapeutics
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• v.16 no.4
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• pp.377-384
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• 2008

Chungpesagan-tang (CST) has been traditionally used in Korea as a therapeutic for cerebral ischemia. To understand the protective mechanism of CST on hypoxia/reoxygenation insults in N2a cells, the cell viability was determined with the treatment of water solution and several solvent fractions of CST. The highest cell viability occurred when the cells were treated with the hexane soluble fraction of CST. Hypoxia/reoxygenation insults were shown to decrease the glutathione peroxidase (GPx) activity and the level of glutathione (GSH) and increase the superoxide dismutase (SOD) activity. However, treatment with hexane soluble fraction of CST ranging from 0.1 ${\mu}g$/ml to 10 ${\mu}g$/ml recovered the activities of GPx and SOD and maintained the levels of MDA and GSH at control levels. While hypoxia/reoxygenation insults induced the activation of ERK in N2a cells, treatment with the hexane soluble fraction of CST inhibited the activation of ERK in a concentration dependent manner. In this study, we were able to demonstrate that the bioactive compounds of CST can be effectively transferred into the hexane soluble fraction, and more importantly that CST exhibits protective effects against hypoxia/reoxygenation insults most likely by recovering redox enzyme activities.

• Molecules and Cells
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• v.26 no.3
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• pp.285-290
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• 2008

Estrogen-induced proliferation in estrogen receptor (ER)-positive breast cancer cells is primarily mediated through two distinct intracellular receptors, $ER{\alpha}$ and $ER{\beta}$. Although tumor necrosis factor alpha ($TNF{\alpha}$) and $E2/ER{\alpha}$ are known to exert opposing effects on cell proliferation in MCF-7 cells, the mechanism by which $TNF{\alpha}$ antagonizes $E2/ER{\alpha}$-mediated cell proliferation is not well understood. The present study suggests that reduced cell survival in response to $TNF{\alpha}$ treatment in MCF-7 cells may be associated with the down-regulation of $ER{\alpha}$ protein. The decrease in $ER{\alpha}$ protein level was accompanied by an inhibition of $ER{\alpha}$ gene transcription. Cell viability was decreased synergistically by the combined treatment with $ER{\alpha}$-siRNA and $TNF{\alpha}$. Furthermore, pretreatment of cells with the PI3-kinase (PI3K)/ Akt inhibitor, LY294002, markedly enhanced $TNF{\alpha}$-induced down-regulation of the $ER{\alpha}$ protein, suggesting that the PI3K/Akt pathway might be involved in control of the $ER{\alpha}$ level. Moreover, down-regulation of $ER{\alpha}$ by $TNF{\alpha}$ was not inhibited in cells that were pretreated with the proteasome inhibitors, MG132 and MG152, which suggests that proteasome-dependent proteolysis does not significantly influence $TNF{\alpha}$-induced down-regulation of $ER{\alpha}$ protein. In contrast, the effect of the PI3K/Akt inhibitor on $ER{\alpha}$ was blocked in cells that were treated with LY294002 in the presence of the proteasome inhibitors. Collectively, our findings show that the $TNF{\alpha}$ may partly regulate the growth of MCF-7 breast cancer cells through the down-regulation of $ER{\alpha}$ expression, which is primarily mediated by a PI3K/Akt signaling.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.140-145
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• 2009

All organisms are being exposed to harmful factors present in the environmental. The combined action of various factors is a distinguishing feature of modern life. An interaction between two chemicals is considered as synergistic when the effect produced is greater than the sum of the two single responses. The biological effects due to the combined action of ionizing radiation with the other factor are hard to estimate and predict in advance. In the current study, we investigated the synergistic effects between ionizing and $HgCl_2$ using fish hepatoma cells (PLHC-1 cells). The results showed a dramatic decrease of cell viability after simultaneous treatment of PLHC-1 cells with ionizing radiation and $HgCl_2$. Neiither of the two had any cytotoxic effect when treated alone. The cytotoxicity of ionizing radiation was enhanced in the presence of $HgCl_2$. The synergistic effects were observed after exposure of the PLHC-1 cells to ionizing radiation combined with $HgCl_2$. The synergistic interaction was due to an increase of irreversibly damaged cells after the combined exposure. Analysis of the extent of synergistic interaction enables to make quantitative estimation of irreversibly damaged cells after the combined exposure. The present study suggests that PLHC-1 cells can serve as rapid screening tools for detecting the toxicity of harmful factors.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.297-304
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• 2015

The flower buds of Sophora japonica L (SF), as a well-known traditional Chinese medicinal herb, have been used to treat bleeding-related disorders such as hematochezia, hemorrhoidal bleeding, dysfunctional uterine bleeding, and diarrhea. However, no specific anti-cancer effect and its molecular mechanism of SF have been described. Thus, we performed in vitro study to investigate if treatment of SF affects activating transcription factor 3 (ATF3) expression and ATF3-mediated apoptosis in human colorectal cancer cells. The effects of SF on cell viability and apoptosis were measured by MTT assay and Western blot analysis against cleaved poly (ADP-ribose) polymerase (PARP). ATF3 activation induced by SF was evaluated using Western blot analysis, RT-PCR and ATF3 promoter assay. SF treatment caused decrease of cell viability and increase of apoptosis in a dose-dependent manner in HCT116 and SW480 cells. Exposure of SF activated the levels of ATF3 protein and mRNA via transcriptional regulation in HCT116 and SW480 cells. Inhibition of extracellular signal-regulated kinases (ERK) 1/2 by PD98059 and p38 by SB203580 attenuated SF-induced ATF3 expression and transcriptional activation. Ectopic ATF3 overexpression accelerated SF-induced cleavage of PARP. These findings suggest that SF-mediated apoptosis may be the result of ATF3 expression through ERK1/2 and p38-mediated transcriptional activation.

• Preventive Nutrition and Food Science
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• v.13 no.2
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• pp.84-89
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• 2008

This study was designed to investigate the protective effect of a methanol extract of Chungkookjang (CKJ) on high glucose induced oxidative stress in LLC-$PK_1$ cells (renal tubular epithelial cells), which are susceptible to oxidative stress. Freeze dried CKJ powder was extracted with methanol, and the extract solution was concentrated, and then used in this study. To determine the protective effect of CKJ extract, oxidative stress was induced by exposing of LLC-$PK_1$ cells to high glucose (30 mM) or normal glucose (5 mM) for 24 hr. Exposure of LLC-$PK_1$ cells to high glucose for 24 hr resulted in a significant (p<0.05) decrease in cell viability, catalase, SOD and GSH-px activity and a significant (p<0.05) increase in intracellular ROS level and thiobarbituric acid reactive substances (TBARS) formation in comparison to the cells treated with 5 mM glucose. CKJ extract treatment decreased intracellular ROS level and TBARS formation, and increased cell viability and activities of antioxidant enzymes including catalase, SOD and GSH-px in high glucose pretreated LLC-$PK_1$ cells. These results suggest that CKJ extract may be able to protect LLC-$PK_1$ cells from high glucose-induced oxidative stress, partially through the antioxidative defense systems.

• Preventive Nutrition and Food Science
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• v.13 no.2
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• pp.90-94
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• 2008

The protective effect of chungkukjang from Sunchang province against oxidative stress was evaluated in the cellular system using LLC-$PK_1$ renal epithelial cells. The LLC-$PK_1$ cells showed decrease in cell viability and elevation in lipid peroxidation by the treatment with the generators of nitric oxide (NO) and superoxide anion ($O_2^-$) produced by sodium nitrouprusside and pyrogallol, respectively. However, the methanol extract of chungkukjang significantly inhibited cellular loss and lipid peroxidation in a dose-dependent manner; in particular K chungkukjang (KC) exerted the strongest protective effect. In addition, the protective effect of chungkukjang from 3-morpholinosydnonimine, as a source of peroxynitrite, with simultaneous generations of NO and $O_2^-$, was also studied. Treatment with chungkukjangs significantly preserved the cell viability and inhibited lipid peroxidation caused by SIN-1 with dose-dependence. The present study suggests that chungkukjang from Sunchang province, especially KC, would have protective potential from oxidative stress induced by free radicals under cellular oxidative damage.

• Journal of The Korean Society of Clinical Toxicology
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• v.15 no.2
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• pp.107-115
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• 2017

Purpose: Glehnia littoralis has been used to treat ischemic stroke, phlegm, cough, systemic paralysis, antipyretics and neuralgia. The pharmacological mechanisms of Glehnia littoralis include calcium channel block, coumarin derivatives, anticoagulation, anti-convulsive effect, as well as anti-oxidant and anti-inflammatory effects. Alpha-amanitin (${\alpha}$-amanitin) is a major toxin from extremely poisonous Amanita fungi. Oxidative stress, which may contribute to severe hepatotoxicity was induced by ${\alpha}$-amanitin. The aim of this study was to investigate whether Glehnia littoralis ethyl acetate extract (GLEA) has the protective antioxidant effects on ${\alpha}$-amanitin -induced hepatotoxicity. Methods: Human hepatoma cell line HepG2 cells were pretreated in the presence or absence of GLEA (50, 100 and $200{\mu}g/ml$) for 4 hours, then exposed to $60{\mu}mol/L$ of${\alpha}$-amanitin for an additional 4 hours. Cell viability was evaluated using the MTT method. AST, ALT, and LDH production in a culture medium and intracellular MDA, GSH, and SOD levels were determined. Results: GLEA (50, 100 and $200{\mu}g/ml$) significantly increased the relative cell viability by 7.11, 9.87, and 14.39%, respectively, and reduced the level of ALT by 10.39%, 34.27%, and 52.14%, AST by 9.89%, 15.16%, and 32.84%, as well as LDH by 15.86%, 22.98%, and 24.32% in culture medium, respectively. GLEA could also remarkably decrease the level of MDA and increase the content of GSH and SOD in the HepG2 cells. Conclusion: In the in vitro model, Glehnia littoralis was effective in limiting hepatic injury after ${\alpha}$-amanitin poisoning. Its antioxidant effect is attenuated by antidotal therapy.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.96-104
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• 2020

Objectives: Oleanolic acid, a minor element of ginsenosides, and its derivatives have been shown to have cytotoxicity against some tumor cells. The impact of cytotoxic effect of oleanolic acid 3-acetate on ovarian cancer SKOV3 cells and endometrial cancer HEC-1A cells were examined both in vivo and in vitro to explore the underlying mechanisms. Methods: Cytotoxic effects of oleanolic acid 3-acetate were assessed by cell viability, phosphatidylserine exposure on the cell surface, mitochondrial release of cytochrome C, nuclear translocation of apoptosis-inducing factor, depolarization of mitochondrial transmembrane potential (∆Ψ_m), and generation of reactive oxygen species (ROS). In vivo inhibition of tumor growth was also assessed with xenografts in immunocompromised mice. Results: Oleanolic acid 3-acetate exhibited potent cytotoxicity toward SKOV3 and HEC-1A cells by decreasing cell viability in a concentration-dependent manner. Importantly, oleanolic acid 3-acetate effectively suppressed the growth of SKOV3 cell tumor xenografts in immunocompromised mice. Furthermore, oleanolic acid 3-acetate induced apoptotic cell death as revealed by loss of ∆Ψ_m, release of cytochrome c, and nuclear translocation of apoptosis-inducing factor with a concomitant activation of many proapoptotic cellular components including poly(ADP-ribose) polymerase, Bcl-2, and caspases-8, caspase-3, and caspase-7. Oleanolic acid 3-acetate, however, caused a decrease in ROS production, suggesting the involvement of an ROS-independent pathway in oleanolic acid 3-acetate-induced apoptosis in SKOV3 and HEC-1A cells. Conclusion: These findings support the notion that oleanolic acid 3-acetate could be used as a potent anticancer supplementary agent against ovarian and endometrial cancer. Oleanolic acid 3-acetate exerts its proapoptotic effects through a rather unique molecular mechanism that involves an unconventional ROS-independent but mitochondria-mediated pathway.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.369-379
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• 2019

Alzheimer's disease (AD) is the most common neurodegenerative disease associated with age, and amyloid beta ($A{\beta}$) is known to cause Alzheimer's disease. In the present study, we investigated the protective effects of Cirsium japonicum var. maackii extract and its fractions against $A{\beta}$-induced neurotoxicity in C6 glial cells. The cells treated with $A{\beta}_{25-35}$ showed a decrease in cell viability and an increase in reactive oxygen species (ROS) production compared with the non-treated cells. However, the cells treated with the C. japonicum var. maackii extract and its fractions increased the cell viability and inhibited the $A{\beta}$-induced ROS production. These results demonstrate the neuroprotective effects of C. japonicum var. maackii against $A{\beta}$. To further examine the protective mechanism, we measured inflammation and apoptosis related protein expressions. The cells treated with extract and fractions from C. japonicum var. maackii down-regulated inflammatory related proteins such as cyclooxygenase-2, interleukin $(IL)-1{\beta}$, and IL-6, and attenuated apoptosis related proteins including B-cell lymphoma-2 (Bcl-2) associated X protein/Bcl-2 ratio. In particular, the ethanol and ethylacetate fraction exhibited higher inhibitory effect against ROS production and apoptosis-related protein expressions among the extract and the other fractions. Therefore, this study demonstrated the protective effects of C. japonicum var. maackii extract and its fractions against $A{\beta}$-induced neurotoxicity in C6 glial cells through the regulation of oxidative stress, inflammation, and apoptosis, suggesting that it might have potential as a therapeutic for AD.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.138-147
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• 2021

The overproduction of reactive nitrogen species (RNS) and reactive oxygen species (ROS) causes oxidative damage to neuronal cells, leading to the progression of neurodegenerative diseases. In this study, we determined the nitric oxide radical (NO), hydroxyl radical (·OH), and superoxide anion radical (O₂^-) scavenging activities of apigenin. Our results showed that apigenin exhibited remarkable, concentration-dependent ·OH, O₂^-, and NO radical scavenging activities. Particularly, apigenin indicated the strongest ·OH radical scavenging activity with 93.38% in the concentration of 100 µM. Furthermore, we also investigated the protective effects of apigenin against hydrogen peroxide (H₂O₂)-induced oxidative stress in SH-SY5Y cells. The H₂O₂ treatment resulted in a significant decrease in cell viability, as well as an increase in lactate dehydrogenase (LDH) release and ROS production compared with the H₂O₂-nontreated SH-SY5Y cells. However, the cell viability significantly increased in the apigenin-treated group, as well as inhibited ROS generation and LDH release compared with the H₂O₂-induced control group. To elucidate the protective mechanisms of apigenin against oxidative stress in SH-SY5Y, we analyzed the apoptosis-related protein expression. The apigenin treatment resulted in the downregulated expression of apoptosis-related protein markers, such as cytochrome C, cleaved caspase-3, poly (ADP)-ribose polymerase (PARP), and B-cell lymphoma 2-associated X (Bax), as well as the upregulated expression of anti-apoptosis markers such as B-cell lymphoma 2 (Bcl-2). In this study, we report that apigenin exhibits a neuroprotective effect against oxidative stress in SH-SY5Y cells. These results suggest that apigenin may be considered as a potential agent for neurodegenerative disease prevention.