• 대한한방내과학회지
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• 제27권1호
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• pp.27-39
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• 2006

Objectives : Induction of CYP2E1 by ethanol is believed to be one of the major mechanism by which ethanol generate a state of oxidative stress. Previous studies showed that treatment with Chungganhaeju-tang prevents hepatic inflammation and apoptosis in alcoholic liver disease. The purpose of our study is to determine if Chungganhaeju-tang can also protect against alcohol-induced cytotoxicity in CYP2E1-transfected HepG2 cells. Materials and Methods : CYP2E1-transfected HepG2 cells and control vector-transfected HepG2 cells were exposed for isx hours to Chungganhaeju-tang, and then 50 mM of ethanol was added and left for two days. Results : Ethanol significantly decreased cell viability in CYP2E1-transfected HepG2 cells and increased apoptosis. These alterations were attenuated by Chungganhaeju-tang. This was accompanied by an improvement of NF-${\kappa}B$ and Akt activation. Conclusion : These results suggest that Chungganhaeju-tang exerts inhibitory effect against the cytotoxicity induced by alcohol in CYP2E1-transfected HepG2 cells, and that this is a protective action due, at least in part, to an activation of NF-${\kappa}B$ that plays a key role in the protection mechanism, and in reducing hepatotoxic cytokine gene expression.

• BMB Reports
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• 제52권8호
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• pp.520-525
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• 2019

Dihydroartemisinin (DHA) has been reported to possess anti-cancer activity against many cancers. However, the pharmacologic effect of DHA on HBV-positive hepatocellular carcinoma (HCC) remains unknown. Thus, the objective of the present study was to determine whether DHA could inhibit the proliferation of HepG2.2.15 cells and uncover the underlying mechanisms involved in the effect of DHA on HepG2.2.15 cells. We found that DHA effectively inhibited HepG2.2.15 HCC cell proliferation both in vivo and in vitro. DHA also reduced the migration and tumorigenicity capacity of HepG2.2.15 cells. Regarding the underlying mechanisms, results showed that DHA induced cellular senescence by up-regulating expression levels of proteins such as p-ATM, p-ATR, ${\gamma}-H_2AX$, P53, and P21 involved in DNA damage response. DHA also induced autophagy (green LC3 puncta gathered together and LC3II/LC3I ratio increased through AKT-mTOR pathway suppression). Results also revealed that DHA-induced autophagy was not linked to senescence or cell death. TPP1 (telomere shelterin) overexpression could not rescue DHA-induced anticancer activity (cell proliferation). Moreover, DHA down-regulated TPP1 expression. Gene knockdown of TPP1 caused similar phenotypes and mechanisms as DHA induced phenotypes and mechanisms in HepG2.2.15 cells. These results demonstrate that DHA might inhibit HepG2.2.15 cells proliferation through inducing cellular senescence and autophagy.

• Journal of Veterinary Science
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• 제23권1호
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• pp.4.1-4.15
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• 2022

Background: Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the antiadipogenic effects of flavonoids are unclear. Objectives: The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells. Methods: The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis. Results: The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators. Conclusion: The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.384-389
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• 2014

Adiponectin, an adipokine predominantly secreted from adipose tissue, exhibits diverse biological responses, including metabolism of glucose and lipid, and apoptosis in cancer cells. Recently, adiponectin has been shown to modulate autophagy as well. While emerging evidence has demonstrated that autophagy plays a role in the modulation of proliferation and apoptosis of cancer cells, the role of autophagy in apoptosis of cancer cell caused by adiponectin has not been explored. In the present study, we demonstrated that globular adiponectin (gAcrp) induces both apoptosis and autophagy in human hepatoma cell line (HepG2 cells) and breast cancer cells (MCF-7), as evidenced by increase in caspase-3 activity, Bax, microtubule-associated protein light chain 3-II (LC3 II) protein levels, and autophagosome formation. Interestingly, gene silencing of LC3B, an autophagy marker, significantly enhanced gAcrp-induced apoptosis in both HepG2 and MCF-7 cell lines, whereas induction of autophagy by rapamycin, an mTOR inhibitor, significantly prevented gAcrp-induced apoptosis in hepatoma cells HepG2. Furthermore, modulation of autophagy produced similar effects on gAcrp-induced Bax expression in HepG2 cells. These results implicate that induction of autophagy plays a regulatory role in adiponectin-induced apoptosis of cancer cells, and thus inhibition of autophagy would be a novel promising target to enhance the efficiency of cancer cell apoptosis by adiponectin.

• 대한화학회지
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• 제59권1호
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• pp.22-30
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• 2015

본 연구에서는 디프테리아 독소가 세포막의 지질에 미치는 영향을 알아보기 위해 HepG2 세포에서 포스포리파제 D와 유리된 지방산(Free fatty acid)의 변화를 살펴보았다. 지질변화는 pH 5.1에서 최고 값을 나타냈으며, 이 pH에서 포스포리파아제 D의 활성을 3.5배 가량, 유리된 지방산의 방출은 5배 정도 증가되었다. 이는 디프테리아 독소가 세포 안으로 들어가는 과정에서 세포막이 교란되어 재배열되었음을 시사한다. 한편 세포막을 무작위로 교란시키는 디지토닌의 영향이 디프테리아 독소의 그것보다 중성 pH에서 4배 이상 상당히 높게 나타난 것으로 미루어 보아 디프테리아 독소의 영향이 상대적으로 선택적인 교란 현상인 것으로 보여진다. 이런 세포막 교란의 연유를 밝히고자 세포막 구멍 형성 저해제인 cibacron blue와 세포막 융합 펩티드를 갖고 있는 hemagglutinin의 영향을 검토하였다. Cibacron blue는 디프테리아 독소에 의한 지질 변화를 50% 정도 저해시켰으며, hemagglutinin에 의한 지질변화는 디프테리아 독소의 그것과 유사함을 관찰 할 수 있었다. 이들 결과들은 디프테리아 독소에 의한 세포막 교란이 구멍형성과 독소의 소수성 펩티드가 세포막에 삽입되는 과정이 서로 연계되어 있음을 암시한다. 그 외 일련의 실험으로 디프테리아 독소가 세포막을 통과하는 과정에서 HepG2 세포의 투과성은 상승시켰으나, 세포의 생존능력은 상당히 높게 유지되었고 DNA 토막내기 같은 세포의 괴사는 일어나지 않았다. 이런 조건하에서 디프테리아 독소는 산성 pH에서 HepG2 세포의 지질의 변화를 가져 온다는 것을 밝힐 수 있었다.

• 생명과학회지
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• 제13권3호
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• pp.324-332
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• 2003

최근 Phenobarbital에 의해서 발현되는 CYP2B유전자의 발현촉진 매개인자로서 Constitutive Androstane Receptor (CAR)가 최근에 규명되었다. 사람의 간암세포인 HepG2 cell line에 CAR유전자를 transfection시켰을 경우 PBRU의 활성을 촉진시켰다. 지금까지 연구된 CAR의 역할은 주로 간세포 내에서 cytochrome P4502B 유전자의 발현을 촉진하는 Phenobarbital의 매개체로서 알려져 있다. 다세포동물에서 각각의 분화된 세포는 독특한 유전자의 발현 Pattern을 갖고 있어서 어느 특정한 세포에서 일어나는 유전자의 발현특징이나 작용기전 혹은 기능이 다른 종류의 세포에서는 일어나지 않거나 상이한 기전에 의해서 조절된다. 이러한 세포간 특이성을 이용하여 유전자 발현에 관여하는 인자들을 규명하는데 기초적 자료로 이용될 수 있다. 따라서 본 연구의 목적은 CYP2B유전자의 발현이 일어나지 않는 콩팥세포 line (COS)에서 CAR 단백질 수용체가 PBRU의 활성촉진에 영향을 미치는지의 여부를 조사하고자 하였다. Control 상태의 Hep G2와 COS 배양세포에서는 CAR 단백질의 발현이 거의 나타나지 않았다. mCAR1-GFP를 transfection 한 후 CAR antibody를 이용하여 immunoblot을 시행하였을 경우, Hep G2 세포에서는 발현이 비교적 약하게 나타났지만, COS 세포에서는 강한 mCAR1-GFP 단백질의 발현을 보였다. 한편, GFP antibody를 이용하여 immunoblot을 시행하였을 경우에는 COS 세포에서 강한 mCAR1-GFP 단백질의 발현을 나타내었을 뿐만 아니라 Hep G2 세포에서도 명백히 단백질의 발현을 관찰할 수 있었다. 또한, Hep G2와 COS세포 모두에서 endogenous RXR의 발현이 일어남을 확인하였고 RXR expression plasmid를 transfection시켰을 때 두 세포 모두에서 단백질의 발현이 현저하게 증가되었다. Constitutive Androstane Receptor (CAR)에 의한 CYP2B의 PBRU 활성효과를 다르게 분화된 세포에서 차이가 일어나는지를 비교하기 위하여 CAR에 의해 매개되는 PBRU의 transactivation효과를 Hep G2와 COS세포에서 조사하였다. Hep G2 세포에서는 transfection된 CAR의 발현에 의해 firefly luciferase 보고단백질의 활성이 약 12배 증가하였다. CAR 발현유전자를 15 ng transfection하였을 때 주어진 보고유전자의 양에 대하여 최대반응을 나타내었고 CYP2B1PBRU가 제거된 CYP2C1 promotor/firefly luciferase를 보고유전자로 사용하였을 때는 CAR에 의한 luciferase의 활성이 나타나지 않았다. Hep G2와는 달리, COS세포에서는 transfection된 CAR의 발현이 PBRU에 의한 firefly luciferase보고단백질의 발현에 영향을 주지 못하였다. 이러한 결과들은 분화된 세포의 종류에 따라서 constitutive androstane receptor의 CYP2BPBRU 활성효과가 다르게 나타날 수 있음을 제시할 뿐만 아니라, 간세포에서 Phenobarbital에 의한 PBRU의 활성유도에 영향을 주는 endogenous 매개 인자들 중 CAR와 RXR과는 다른 전사조절인자들이 필요로 하며 이러한 인자들의 발현이 콩팥 세포에서는 다르게 존재함을 시사한다.

• 약학회지
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• 제43권4호
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• pp.458-463
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• 1999

This study was undertaken to test for antiviral activity of the aqueous extracts prepared from 4 medicinal plants of Korea (Terminalia chebula, Sanguisorba officinalia, Rubus coreanus, Rheum palmatum). Aqueous extracts were assayed for the inhibition of hepatitis B virus (HBV) replication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to $128{\;}\mu\textrm{g}/ml$ and inhibited the production of HBsAg dose-dependently. Among the 4 tested plants, Terminalia chebula exhibits the most prominent anti-HBV activities. Our findings suggest that these 4 medicinal plants may have potential to develop as specific anti-HBV drugs in the future.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1262-1268
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• 2006

In the search for a novel cytotoxic substance from medicinal plants, HY53 ($C_{17}H_{32}O_2N_2$; molecular weight 296) was isolated from the leaves of Pata de Vaca (Bauhinia forficata). The growth of the HepG2 cells was inhibited in a dose-dependent manner when treated with 0.07 to 0.40 mM HY53 for 24 h (IC$_{50}$: 0.13 mM). Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HepG2 cells exposed to 0.27 mM HY53, whereas a flow cytometric analysis of the HepG2 cells using propidium iodide showed that the apoptotic cell population increased gradually from 8% at 0 mM to 23% at 0.14 mM and 45% at 0.40 mM after being exposed to each concentration of HY53 for 24 h. Moreover, a TUNEL assay also exhibited the apoptotic induction of the HepG2 cells treated with HY53. To obtain further information on the HY53-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HepG2 cells with HY53 resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Consequently, the results confirmed that the apoptosis in the HepG2 cells was induced by HY53 and the involvement of caspase-3-mediated PARP cleavage in the apoptotic process.

• 생명과학회지
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• 제19권9호
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• pp.1251-1257
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• 2009

본 연구에서는 오징어내장을 각 용매별로 분획하여 암세포 성장 억제 효과와 quinone reductase (QR) 유도 활성 증가 효과를 알아보았다. 간암 세포인 HepG2, 유방암 세포주인 MCF-7 그리고 대장암 세포주인 HT-29를 이용하여 암세포 성장 억제 효과를 실험한 결과 모든 세포주에서 TPMH층에서 가장 높은 암세포 성장 억제 효과를 나타내었고 다음으로 TPMM층에서도 높은 암세포 성장 억제 효과를 나타내었다. 그리고 HepG2, MCF-7 및 HT-29 세포주에서 모두 농도 의존적인 암세포 성장 억제 효과를 나타내었으나 간암 세포주인 HepG2에서 가장 높은 효과를 나타내어 특히 간암에 대한 예방효과가 기대되어진다. 또한 암 예방 효과를 알아보기 위하여 3종의 암세포 중 유일하게 quinone reductase를 가지고 있는 인체 간암세포주인 HepG2를 이용하여 QR 유도 활성 증가 효과를 측정한 결과, 암세포 성장 억제 효과의 결과에서와는 달리 TPMM층에서 유의적으로 가장 높은 QR 유도 활성 증가 효과를 나타내었고 다음으로 TPMH층에서도 높은 QR 유도 활성 증가 효과를 나타내었다. 본 실험 결과에서 암세포 성장 억제 효과는 오징어내장의 hexane 분획층인 TPMH층에서 가장 높게 나타났으며, QR 유도 활성 효과는 methanol 분획층인 TPMM층에서 가장 높게 나타났으므로 이들 분획층에 유효한 생리활성 물질이 함유되어 있을 가능성 추정되어진다. 따라서 본 연구를 통하여 오징어 부산물인 내장을 이용한 항암 관련 기능성 식품의 개발 가능성이 보이며, 이를 위한 TPMH 분획층과 TPMM 분획층에 대한 집중적인 연구가 요구된다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3289-3294
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• 2016

Naringin, a bioflavonoid found in Citrus seeds, inhibits proliferation of cancer cells. The objectives of this study were to investigate the mode and mechanism(s) of hepatocellular carcinoma HepG2 cell death induced by naringin. The cytotoxicity of naringin towards HepG2 cells proved dose-dependent, measured by MTT assay. Naringin-treated HepG2 cells underwent apoptosis also in a concentration related manner, determined by annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) employing flow cytometry. Mitochondrial transmembrane potential (MTP) measured using 3,3'-dihexyloxacarbocyanine iodide ($DiOC_6$) and flow cytometer was reduced concentration-dependently, which indicated influence on the mitochondrial signaling pathway. Caspase-3, -8 and -9 activities were enhanced as evidenced by colorimetric detection of para-nitroaniline tagged with a substrate for each caspase. Thus, the extrinsic and intrinsic pathways were linked in human naringin-treated HepG2 cell apoptosis. The expression levels of pro-apoptotic Bax and Bak proteins were increased whereas that of the anti-apoptotic Bcl-xL protein was decreased, confirming the involvement of the mitochondrial pathway by immunoblotting. There was an increased expression of truncated Bid (tBid), which indicated caspase-8 proteolysis activity in Bid cleavage as its substrate in the extrinsic pathway. In conclusion, naringin induces human hepatocellular carcinoma HepG2 cell apoptosis via mitochondria-mediated activation of caspase-9 and caspase-8-mediated proteolysis of Bid. Naringin anticancer activity warrants further investigation for application in medical treatment.