• Journal of Life Science
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• v.24 no.6
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• pp.595-602
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• 2014

Styela Clava tunic (SCT) has found some applications in many areas of medical treatment including as an anti-inflammatory compound, a wound healing film, in guided bone regeneration, and as a food additive. The protective effect of SCT aqueous extract (AE-SCT) on cell death induced by $H_2O_2$ treatment was investigated by measuring the changes in cell viability in HepG2 cells after AE-SCT treatment. High concentrations of antioxidant compounds including flavonoids (3.3 mg/g) and phenolics (32.3 mg/g) were detected in AE-SCT but no significant cytotoxicity was observed in HepG2 cells treated with AE-SCT. The viability of HepG2 cells was also not changed by treatment with different concentrations of AE-SCT after $H_2O_2$ treatment. However, cell viability was significantly increased in cells treated with three different concentrations of AE-SCT before $H_2O_2$ treatment. The greatest increase in cell viability was observed in the group treated with $50{\mu}g/ml$ AE-SCT, when compared with vehicle-treated group. FACS and DAPI staining analysis indicated that the decrease in number of dead cells was dependent on the concentration of AE-SCT. Alterations in the Bax/Bcl-2 ratio after $H_2O_2$ treatment were significantly restored by treatment with different concentrations of AE-SCT. These results indicate that AE-SCT, which contains high levels of antioxidants, may protect cells against death induced by $H_2O_2$ treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.373-384
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• 2020

Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and anti-tumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H₂O₂) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl₄). Monomers protected against oxidative stress in HepG2 cells in a dose-response manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of β-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl₄. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H₂O₂-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

• The Journal of Internal Korean Medicine
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• v.29 no.2
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• pp.490-499
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• 2008

Objectives : This study was aimed to elucidate the effects of Trichosanthes kirilowii extract (TKE) on the angiogenesis and growth of tumor cells. Methods : Tube formation assay was performed by using human umbilical vein endothelial cells (HUVEC), and anchorage dependent colony assay was performed by using B16-F10 melanoma, Hep G2 and HT1080, CT-26 and SNU-1 cells. Results : For HUVEC, TKE at a level of more than 100 ${\mu}g/m{\ell}$ suppresses cell growth. For HUVEC at 100 ${\mu}g/m{\ell}$ and greater TKE density, the formation of tubes was suppressed in a dose-dependant manner. TKE controls the colony formations of B16-F10 melanoma cells, CT 26 cells, and Hep G2 cells, and its effect is proportional to density. In HT1080 cells and SNU-1 cells, formation is suppressed regardless of density. Conclusions : From these results, it could be concluded that TKE has significant properties on anti-angiogenesis and growth inhibiting of tumor cells. It is suggested that TKE will be a good candidate for new drugs or therapeutics for anti-angiogenesis.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• Journal of Life Science
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• v.33 no.12
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• pp.1002-1014
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• 2023

The root of Cirsium japonicum var. maackii (Maxim.) has long been used in traditional medicine to prevent the onset and progression of various diseases and has been reported to exert a wide range of physiological effects, including antioxidant activity. However, research on its effects on hepatocytes remains scarce. This study used the human hepatocellular carcinoma HepG2 cell line to investigate the antioxidant activity of ethanol extract of C. japonicum root (EECJ) on hepatocytes. Hydrogen peroxide (H₂O₂) was used to mimic oxidative stress. The results showed that EECJ significantly reverted the decrease in cell viability and suppressed the release of lactate dehydrogenase in HepG2 cells treated with H₂O₂. Moreover, an analysis of changes in cell morphology, flow cytometry, and microtubule-associated protein light chain 3 (LC3) expression showed that EECJ significantly inhibited HepG2 cell autophagy induced by H₂O₂. Furthermore, it attenuated H₂O₂-induced apoptosis and cell cycle disruption by blocking intracellular reactive oxygen species and mitochondrial superoxide production, indicating strong antioxidant activity. EECJ also restored the decreased levels of intracellular glutathione (GSH) and enhanced the expression and activity of superoxide dismutase and GSH peroxidase in H₂O₂-treated HepG2 cells. Although an analysis of the components contained in EECJ and in vivo validation using animal models are needed, these findings indicate that EECJ is a promising candidate for the prevention and treatment of oxidative stress-induced liver cell damage.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7137-7141
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• 2013

Several studies have shown that nemo-like kinase (NLK) plays a vital role in apoptosis of cancer cells. The present research concerned effects and mechanisms of Taxol on NLK knockdown human laryngeal cancerHep-2 cell lines in vitro. Using RNAi, methyl-thiazoltetrazolium (MTT) assays, real-time RT-PCR, Western blotting and flow cytometry analysis, growth and the cell cycle progression of NLK knockdown Hep-2 cells and expression of downstream molecules were observed. Cell growth was obviously suppressed in the Taxol treated group (P<0.001, 48 hours). Cell numbers of combined Taxol-based chemotherapy with lentivirus mediated RNAi treatment group (Lv-shNLK+Taxol goup) were significantly different from NLK-specific siRNA lentivirus infected group (Lv-shNLK group) (p<0.001). Flow cytometry analysis revealed that Lv-shNLK+Taxol caused the G0/G1-phase DNA content to decrease from 44.1 to 3.33% (p<0.001) and the S-phase DNA content to increase from 38.4 to 82.0% (p<0.001), in comparison with the Lv-shNLK+Taxol group. Immunoblot analysis showed that knockdown of NLK led to significant reduction in the levels of cyclin D1, PCNA and PARP, whereas cyclin B1 was elevated in. Cell growth was also obviously suppressed in the Hep-2 cell line, knockdown of NLK making them more sensitive to Taxol treatment. NLK is expected to become a target of new laryngeal cancer gene therapies.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10439-10444
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• 2015

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR-340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.696-701
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• 2008

The objective of this study was to determine whether Codonopsis lanceolata or Platycodon grandiflorum ethyl acetate fraction (CLEA or PGEA) protect cells against sodium nitroprusside (SNP)-induced oxidative stress via the expression of various antioxidant systems. The HepG2 cells exposed for 24 hr to 0.5 mM SNP showed a reduction in the cell viability by an MTT assay. Pretreatment with CLEA and PGEA resulted in an inhibition of SNP-induced cell death. In addition, the effects of CLEA and PGEA on the expression of antioxidant systems via RT-PCR analyses was assessed. The levels of catalase (CAT), glucose-6-phosphate dehydrogenase (G6PD) and metallothionein (MT)-1A mRNA were increased after 24 hr of CLEA exposure. The levels of Mn superoxide dismutase CAT, G6PD, MT-1A, and MT-2A mRNA were increased after PGEA treatment. In conclusion, CLEA and PGEA exert indirect antioxidant effects, perhaps via the induction of a variety of antioxidant systems which, may protect cells against oxidative stress.

• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.208-217
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• 2019

Background: In the present study, we identified two cytotoxic compounds from the root of Rumex crispus L. using a bioassay-based method. Methods and Results: Compared with the other fractions, the diethyl ether ($Et_2O$) fraction of R. crispus root extract exhibited the strongest of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect [scavenging concentration 50% $(SC_{50})=63.8{\pm}1.47{\mu}g/m{\ell}$], nitric oxide (NO) production inhibitory effect on the mouse macrophage cell line RAW264.7 [inhibitory concentration 50% $(IC_{50})=60.9{\pm}7.52{\mu}g/m{\ell}$] and cytotoxicity effect on the human hepatoma cell line, HepG2 [lethal concentration 50% $(LC_{50})=115.4{\pm}1.86{\mu}g/m{\ell}$]. According to the bioassay-based method, two cytotoxic compounds were purified from the $Et_2O$ fraction by using column chromatography and preparative high performance liquid chromatography (prep-HPLC). These two compounds were identified as parietin and chrysophanol by using nuclear magnetic resonance (NMR) and liquid chromatography quadruple time of flight mass spectrometry (LC-QTOF-MS). In addition, both parietin and chrysophanol exhibited a cytotoxicity effect on HepG2 cells, their $LC_{50}$ values were $169.1{\pm}17.67{\mu}M$ and $111.5{\pm}6.62{\mu}M$, respectively. Conclusions: Parietin and chrysophanol isolated from the $Et_2O$ fraction of the R. crispus root extract showed cytotoxicity in HepG2 cell.

• Korean Journal of Pharmacognosy
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• v.38 no.4
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• pp.400-402
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• 2007

Tacrine is an acetylcholinesterase inhibitor that is approved for the treatment of Alzheimer's disease. However, tacrine treatment for Alzheimer's disease results in reversible hepatotoxicity in 30-50% of patients, which seriously limits its clinical use. Accordingly, the identification of constituents in natural products that have protective effects on tacrine-induced hepatotoxicity would be valuable. In the present study, an immortalized human hepatoma cell line, HepG2 was employed to screen for agents that protect against tacrine-induced hepatotoxicity. The bioassay-guided fractionation of water extract of Cassiae Semen furnished two anthraquinones, aurantio-obtusin (1) and obtusifolin (2). Compounds 1 and 2 showed hepatoprotective effects with the protection ratio values of 55.3 +/- 0.5% and 41.2 +/- 0.8% at $160{\mu}M$, respectively.