• Korean Journal of Pharmacognosy
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• v.25 no.2
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• pp.144-152
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• 1994

The combined effects of Ulmi Cortex and some anti-cancer drugs on the proliferation of HeLa cells, Hep G2 cells and S 180 cells were estimated by MTT calorimetric assay. The n-BuOH fraction(UBF) of Ulmi Cortex inhibited the proliferation of HeLa cell at $10^{-3}\;g/ml$, Hep G2 cell at $10^{-5}\;g/ml$ and S 180 cell at $10^{-3}\;g/ml$. The inhibitory effects of mitomycin C(MMC), cisplatin(CPT) and 5-fluorouracil (5-FU), respectively, on Hep G2 cell was increased by the UBF. The UBF did not influence the proliferation of Balb/c 3T3 cells at concentrations of $10^{-6}$ to $10^{-4}\;g/ml$, but increased the proliferation of T cells at concentrations of $10^{-5}$ to $10^{-4}\;g/ml$. The UBF did not influence the number of leukocyte, and on the thymus weight of mice. The UBF increased the number of total-peritoreal cells of mice. In conclusion, the results suggest that the UBF have anti-cancer activity without the side effect, such as leukopenia and immunosuppresion, and increase the inhibitory activity of the anti-cancer drugs on Hep G2 cells.

• Korean Journal of Pharmacognosy
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• v.48 no.4
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• pp.273-279
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• 2017

The aim of this study was to investigate the mechanisms underlying apoptosis induced by a broussochalcone B (BCB) from Broussonetia papyrifera in HepG2 cells. The results showed that BCB treatment for 24 hr significantly inhibited cell viability in a dose-dependent manner, and induced apoptosis in HepG2 cells. More so, BCB treatment triggered the cleavage of caspase-8, -9, -3, poly (ADP-ribose) polymerase (PARP), increase of Bax level, and decrease of Bcl-2 expression. A general caspase inhibitor (z-VAD-fmk) blocked BCB-induced cell death. Furthermore, BCB treatment caused reactive oxygen species (ROS) production in a dose-dependent manner. In addition, an antioxidant N-acetylcysteine (NAC) blocked BCB-induced ROS production and cell death. Therefore, these results indicate that BCB-induced apoptosis is mediated by a caspase dependent pathway and ROS production in HepG2 cells.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.43-53
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• 2019

The anticancer activity of guava (Psidium guajava L.) leaf extract (GLE) occurs via the induction of apoptosis in cancer cells. However, the mechanism behind GLE-induced apoptosis in the human hepatocellular carcinoma cell line HepG2 remains unclear. In the present study, we investigated the apoptotic effects and mechanism of action of GLE in cultured HepG2 cells. The results showed that GLE induced reactive oxygen species (ROS) synthesis and disrupted the mitochondrial membrane potential (${\Delta}{\Psi}m$). Moreover, GLE increased the expression of apoptotic pathway proteins, such as the cleaved forms of caspase-3, -8, and -9; the translocation of Bax and cytochrome c (cyt-c) from the mitochondria to the cytosol; and the downregulation of Bcl-2. In addition, p53 protein expression was increased upon GLE treatment. These observations indicate that the GLE-induced apoptosis in HepG2 cells is mediated by mitochondrial ROS generation, followed by caspase activation and cyt-c release, suggesting that GLE may be a promising candidate for the development of novel drugs for the treatment of liver cancers.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.122-132
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• 1999

Purpose : Hepatitis B virus DNA transfected cell line(HepG2.2.15) was cultured to evaluate the effect of herbs on the expression of HBeAg and the replication of HBV. HepG2.2.15 produces HBV particles as well as viral proteins into cell culture media. Methods : Extracts of herbs were adminitered to the cells on the proper concentration. Culture media was collected 48 hours after the herbal administration and HBeAg level in the media was examined by ELISA method. To confirm that the anti-viral effect was not due to direct cytotocixity of the extracts, normal cell proliferation was shown by cell counting. And as of the interference in protein synthesis of HepG2.2.15 by herb-extracts, we used the result of study that we performed before by ${\alpha}FP$ assay using EIA method. Results& Conclusion : Herb medicines like 地楡(Sanguisorbae Radix) and 覆盆子(Rubi Frusctus) showed significant inhibitory effect on HBeAg expression at p<0.01 and 五味子(Acanthopanacis Cortex) at p<0.05. Whereas, though some herbs such as ?草根(Rubiae Radix), 山査(Crataegii Fructus), 白芍藥(Paeoniae Radix Alba), and 大黃(Rhei Radix et Rhizoma) showed the tendecy to suppress HBeAg. most of them were not significant statistically. From the above, we could conclude that those herb medicines can be applied to patients effectively and further studies on effective fraction of some herbs are thought to be needed.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.903-913
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• 2011

Vibrio parahaemolyticus, which causes gastroenteritis, wound infection, and septicemia, has two sets of type III secretion systems (TTSS), TTSS1 and TTSS2. A TTSS1-deficient vcrD1 mutant of V. parahaemolyticus showed an attenuated cytotoxicity against HEp-2 cells, and a significant reduction in mouse lethality, which were both restored by complementation with the intact vcrD1 gene. V. parahaemolyticus also triggered phosphorylation of mitogen-activated protein kinases (MAPKs) including p38 and ERK1/2 in HEp-2 cells. The ability to activate p38 and ERK1/2 was significantly affected in a TTSS1-deficient vcrD1 mutant. Experiments using MAPK inhibitors showed that p38 and ERK1/2 MAPKs are involved in V. parahaemolyticus-induced death of HEp-2 cells. In addition, caspase-3 and caspase-9 were processed into active forms in V. parahaemolyticus-exposed HEp-2 cells, but activation of caspases was not essential for V. parahaemolyticus-induced death of HEp-2 cells, as shown by both annexin V staining and lactate dehydrogenase release assays. We conclude that secreted protein(s) of TTSS1 play an important role in activation of p38 and ERK1/2 in HEp-2 cells that eventually leads to cell death via a caspase-independent mechanism.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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• pp.185-190
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• 2010

This paper presents the estimation on switching technique via output power source analysis of power conversion unit in electric railway vehicle. The focus of this study suggested an alternative on critical problems by using head electric power(HEP). To achieve this, we have measured output power of HEP, and measurement devices set up at output of transformer connected HEP to analysis quality on output power source of head electric power(HEP) unit in electric railway vehicle. Using results of measurement of it, parameters are assumed for simulation to confirm estimation on switching technique. It is confirmed that switching technique is Selected Harmonic Elimination PWM(SHEPWM) and inverter switching frequency is less than 500[Hz]. Throughout experiment and simulation, it is estimated that switching technique used HEP is advanced SHEPWM and switching frequency is about 300[Hz]. Also leakage inductance in transformer is about $180[{\mu}H]$ less than $365[{\mu}H]$ known.

• Journal of Life Science
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• v.17 no.10
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• pp.1447-1451
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• 2007

Through the screening of marine natural compounds that inhibit cancer cell proliferation, we previously reported that pectenotoxin-2 (PTX-2) isolated from marine sponges exhibits selective cytotoxicity against several cell lines in p53-deficient tumor cells compared to those with functional p53. However, the molecular mechanisms of its anti-proliferative action on malignant cell growth are not completely known. To further explore the mechanisms of its anti-cancer activity and to test whether the status of p53 in liver cancer cells correlates with their chemo-sensitivities to PTX-2, we used two well-known hepatocarcinoma cell lines, p53-deficient Hep3B and p53-wild type HepG2. We have demonstrated that PTX-2 markedly inhibits Hep3B cell growth and induces apoptosis whereas HepG2 cells are much more resistant to PTX-2 suggesting that PTX-2 seems to act by p53-independent cytotoxic mechanism. The apoptosis induced by PTX-2 in Hep3B cells was associated with the modulation of DNA fragmentation factor (DFF) family proteins, up-regulation of pro-apoptotic Bcl-2 family members such as Bax and Bcl-xS and activation of caspases (caspase-3, -8 and -9). Blockade of the caspase-3 activity by caspase-3 inhibitor, z-DEVD-fmk, prevented the PTX-2-induced growth inhibition in Hep3B cells. Moreover, treatment with PTX-2 also induced phosphorylation of AKT and extracellular-signal regulating kinase (ERK), but not c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MARK). Specific inhibitors of PI3K inhibitor (LY294002) and ERK1/2 inhibitor (PD98059) significantly blocks PTX-2-induced-anti-proliferative effects, whereas a JNK inhibitor (SP600125) and a p38 MAPK inhibitor (SB203580) have no significant effects demonstrating that the pro-apoptotic effect of PTX-2 mediated through activation of AKT and ERK signal pathway in Hep3B cells.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.97-104
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• 2017

BACKGROUND/OBJECTIVE: Although Angelica keiskei (AK) has widely been utilized for the purpose of general health improvement among Asian, its functionality and mechanism of action. The aim of this study was to determine the protective effect of ethanol extract of AK (AK-Ex) on acute hepatotoxicity induced by acetaminophen (AAP) in HepG2 human hepatocellular liver carcinoma cells and HepaRG human hepatic progenitor cells. MATERIALS/METHODS: AK-Ex was prepared HepG2 and HepaRG cells were cultured with various concentrations and 30 mM AAP. The protective effects of AK-Ex against AAP-induced hepatotoxicity in HepG2 and HepaRG cells were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, lactate dehydrogenase (LDH) assay, flow cytometry, and Western blotting. RESULTS: AK-Ex, when administered prior to AAP, increased cell growth and decreased leakage of LDH in a dose-dependent manner in HepG2 and HepaRG cells against AAP-induced hepatotoxicity. AK-Ex increased the level of Bcl-2 and decreased the levels of Bax, Bok and Bik decreased the permeability of the mitochondrial membrane in HepG2 cells intoxicated with AAP. AK-Ex decreased the cleavage of poly (ADP-ribose) polymerase (PARP) and the activation of caspase-9, -7, and -3. CONCLUSIONS: These results demonstrate that AK-Ex downregulates apoptosis via intrinsic and extrinsic pathways against AAP-induced hepatotoxicity. We suggest that AK could be a useful preventive agent against AAP-induced apoptosis in hepatocytes.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.743-747
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• 2014

In this study, drop-on-demand system using piezo-elecrtric inkjet printers was employed for preparation of collagen microspheres, and its application was made to the HepG2 cell-laden microsphere preparation. The collagen microspheres were injected into beaker filled with mineral oil and incubated in a water bath at $37^{\circ}C$ for 45 minutes to induce gelation of the collagen microsphere. The size of collagen microsphere was $100{\mu}m$ in diameter and $80{\mu}m$ in height showing spherical shape. HepG2 cells were encapsulated in the collagen microsphere. The cell-laden microspheres were inspected by the microscopic images. The encapsulation of cells may be beneficial for applications ranging from tissue engineering to cell-based diagnostic assays.

• The Journal of Internal Korean Medicine
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• v.18 no.1
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• pp.48-61
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• 1997

In this study, antineoplastic activity against human hepatocellular carcinoma cell line(Hep G2) was tested in Gleditsiae Spina. Gleditsiae Spina was extracted with water, and the cytotoxic activity was tested using a calorimetric tetrazolium assay(MTT assay), the apoptosis was tested using a DNA electrophoresis and flow cytometry. The nitric oxide production from mouse peritoneal macrophage was tested using a Griess method. Gleditsiae Spina extracts against the proliferation of Hep G2 cells not showed cytotoxicity at the concentration of less than $100{\mu}g/ml$, and Gleditsiae Spina extracts not showed the cytotoxicity of mitomycin C and the cytotoxicity of cisplatin on Hep G2 cells. Gleditsiae Spina extracts aginist the proliperation of BALB/c 3T3 cells not showed cytotoxicity, the proliperation of mouse thymocytes and splenocytes not showed cytotoxicity at the concentration of less than $100{\mu}g/ml$. Gleditsiae Spina extracts not showed nitric oxide production from mouse peritoneal macrophage in vitro. Gleditsiae Spina was administered orally for 7 days at 300mg/kg increased nitric oxide production from mouse peritoneal macrophage.