• Journal of Microbiology
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• 제38권4호
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• pp.270-274
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• 2000

Pathogenic Salmonella typhimurium can invade the intestinal epithelium and cause a wide range of diseases including gastroenteritis and bacteremia in human and animals. To identify the genes involved in the infection, the invasion determinant was obtained from S. typhimurium 82/6915 and was subcloned into pGEM-7Z. A subclone DHl (pSV6235) invaded HEp-2 and Chinese hamster ovary epithelial cells and contained a 4.4 kb fragment of S. typhimurium genomic region. Compared with the host strain E. coli DHl, the subclone DHl (pSV6235) invaded cultured HEp-2 and Chinese hamster ovary cells at least 75- and 68-fold higher, respectively. The invasion rate of E. coli DHl for the cells significantly increased by harbouring the genomic region derived from pathogenic S. typhimurium 82/6915.

• Archives of Pharmacal Research
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• 제28권12호
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• pp.1376-1380
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• 2005

In this study, ethanolic extracts from 18 seaweed variants were assessed for hepatoprotective activity against tacrine-induced cytotoxicity in Hep G2 cells. Only one of these, Ecklonia stolonifera Okamura (Laminariaceae), a member of the brown algae, exhibited promising hepatoprotective activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction obtained from the ethanolic extract of E. stolonifera, resulted in the isolation of several phlorotannins [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 2 and 4 were determined to protect Hep G2 cells against the cytotoxic effects of tacrine, with $EC_{50}$ values of 62.0 and 79.2 $\mu$g/mL, respectively. Silybin, a well characterized hepatoprotective agent, was used as a positive control, and exhibited an $EC_{50}$ value of 50.0 $\mu$g/mL. It has been suggested that the phlorotannins derived from marine brown algae might prove useful sources in the development of novel hepatoprotective agents.

• 대한의생명과학회지
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• 제28권1호
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• pp.25-33
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• 2022

The imbalance of oxidative stress due to the excessive production of reactive oxygen species (ROS) leads to the pathogenesis of liver disease. To prevent this, the role of antioxidant mechanisms is important. Antioxidant studies have been reported on the Filipendula glaberrima Nakai. However, studies applied to HepG2 cells, which are human liver cells, have not yet been conducted. In this study, 70% ethanol extract of Filipendula glaberrima Nakai (FGE) was prepared and antioxidant activity was investigated. It was confirmed whether FGE pretreatment could reduce hydrogen peroxide-induced oxidative stress in HepG2 cells. The increase in gene expression of antioxidant biomarkers and the scavenging ability of ROS were measured, and Hoechst 33342 staining was used to know the inhibitory effect of the apoptosis. As a result, FGE significantly increased SOD (2.6-fold), CAT (4.4-fold), MT-1A (3.1-fold), GPx (4-fold), and G6PD (2.4)-fold compared to the H₂O₂-treated group. FGE directly inhibited ROS production from 13.4 to 3.6 (the fluorescence mean of DCF-DA) and also reduced apoptotic cells from 45% to 10% (Hoechst 33342 staining) at 2.5 ㎍/mL. These results demonstrate the excellent antioxidant activity of FGE and show that it can be used as a functional food to prevent liver disease.

• Molecules and Cells
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• 제26권2호
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• pp.140-145
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• 2008

Expression of olive flounder hepcidin I (HepI) fused with truncated OmpA signal peptides ($OmpASP_{tr}$) as directional signals does not produce soluble fusion proteins. However, by inserting amino acid segments (xxx) varying in pI and hydrophobicity/hydrophilicity into a leader sequence containing a truncated OmpASP ($OmpASP_{tr}$) and a factor Xa cleavage site (Xa) [$OmpASP_{tr}{\mid}(xxx){\mid}Xa$], we were able in some cases to express soluble recombinant HepI. Soluble expression of the recombinant protein strongly correlated with (xxx) insertions of high pI and hydrophilicity. Therefore, we modified the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence by inserting Arg and Lys into (xxx) to increase the hydrophilicity of the signal peptide region. These modifications enhanced the expression of soluble recombinant HepI. Hydropathic profile analysis of the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ HepI fusion proteins revealed that the transmembrane-like domains derived from the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence were larger than the internal positively charged domain native to HepI. It should therefore be possible to overcome the obstacle of internal positively charged domains to obtain soluble expression of recombinant proteins by monitoring the hydrophilicity and hydropathic profile of the signal peptide region using a computer program.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.512-519
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• 2008

Three different polysaccharide-peptide complexes (PPC, named as Fr-I, Fr-II, and Fr-III) were produced by submerged mycelial culture of an entomopathogenic fungus Cordyceps sphecocephala, and their anticancer activities were investigated in human hepatocarcinoma (HepG2) and neuroblastoma (SK-N-SH) cells. The highest inhibitory effects of PPC on both HepG2 and SK-N-SH cells were achieved with Fr-I, whereas Fr-III with low molecular mass showed lower inhibition effects. Interestingly, the inhibitory effects of the three fractions were increased after protease digestion, suggesting that the inhibitory effects resulted mainly from the carbohydrate moiety, at least in the case of Fr-II and Fr-III, of PPC. The results of DNA fragmentation in PPC-induced apoptotic cells were confirmed by both DNA ladder assay and comet assay. Our investigation also showed that PPC-induced apoptosis of both cancer cells was associated with intracellular events including DNA fragmentation, activation of caspase-3, and modulation of Bcl-2 and Bax. We conclude that PPC has potential as a novel therapeutic agent for the treatment of both HepG2 and SK-N-SH cancer cells without any cytotoxicity against normal cells.

• Journal of Nutrition and Health
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• 제44권6호
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• pp.488-497
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• 2011

Oxygen is necessary to sustain life, yet cellular oxygen metabolism creates destructive elements called free radicals. Free radicals are chemically unbalanced and carrying free electrons that can damage molecules, potentially damaging the cell itself. For this reason, many antioxidant products, including supplements and functional foods, are being developed. In particular, natural products are rich sources of pharmacologically active compounds. The purpose of this study was to investigate the antioxidant effects of target biomaterials in Korean traditional spices such as diallyl sulfide (DAS), capsaicin (CAP), and gingerol (GGR), and to investigate the response of the antioxidant defense system to oxidative stress by hydrogen peroxide ($H_2O_2$) compared to sulforaphane (SFN) in HepG2 cells. After the analysis of the cell viability using Cell Counting kit-8 (CCK-8) assay, we determined that the optimum levels were $200{\mu}M$ DAS, $25{\mu}M$ CAP, $50{\mu}M$ GGR, and $12.5{\mu}M$ SFN. Antioxidant enzymes were measured and protein expression was detected by Western blotting. All treatments showed a significant decrease in antioxidant enzyme activity such as superoxide dismutase, catalse, and glutathione peroxidase in HepG2 cells. Additionally, DAS, CAP, GGR and SFN increased the antioxidant system-related transcription factor Nrf2 which was found to be regulated by the activation of MAPK-JNK in this study. In conclusion, these results indicate the protective effects of DAS CAP, GGR, and SFN against $H_2O_2$-induced oxidative stress.

• 동국한의학연구소논문집
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• 제7권2호
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• pp.155-162
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• 1999

귀전우(Euonymus alatus Sieb.)가 간암, 식도암, 위암, 자궁암등의 각종 암을 치료하는 방법으로 민방에서 많이 사용하고 있다. 실제 Euonymus alatus(Thumb.) Sieb의 추출물중 Eupolyphaga simensis(ES)는 HDL-C/TC ratio와 LCATactivity를 증진시킨다. Human hepatoblastoma 세포인 Hep3B 세포의 성장억제를 유도하는 factor로는 TGF-${\beta}$, Insulin 등으로 알려져 있다. 따라서 귀전우는 간에 있어 당 대사에 관여하는 plasma HDL3-C level은 낮게 유지함으로써 간에서 지방간 이행을 억제 하여 간에서의 암 발생을 억제하는 효과를 보인다. 실험에서 귀전우가 자궁암세포보다도 간암세포에 보다 높은 세포독성을 보임으로써 여러종류의 암에 모두 적용하기는 어렵다고 보여진다. 또한 귀전우가 바이러스에 의해 유도되는 간암과 hepatocellular Carcinoma 세포에서 효과가 있는지와 HCC에서 세포의 증식억제효과를 어떤 경로를 통해 이루어지는지 계속적으로 연구가 수행되어져야 될 것이다.

• 접착 및 계면
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• 제17권4호
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• pp.149-154
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• 2016

일반적으로, 화학 물리적 변성이 수반되는 멸균방법을 적용하지 못하는 경우 필터여과에 의한 멸균 방법을 주로 사용한다. 하지만 바이러스의 경우 100 nm의 작은 크기로 인해 박테리아 제거에 사용되는 필터여과에 의한 멸균 방법을 적용하기가 어렵다. 본 논문에서는 화학 물리적 변성 없이 바이러스를 비활성화하는 물질 개발을 위하여, 카테콜기가 도입된 헤파린 고분자(Hep-C)를 합성하였다. Hep-C의 바이러스 비활성화 효과를 알아보기 위해서 표면이 노르에피네프린으로 코팅된 조직배양접시에 아데노연관바이러스(Adeno-associated virus; AAV)를 고정화하였으며, 그 위에 다시 Hep-C를 코팅하여 녹색형광단백질(GFP) 유전자를 전달할 수 있는 AAV의 비활성화 정도를 유세포분석기(FACS)를 이용하여 분석하였다. 그 결과 AAV에 Hep-C를 도포하면 99%에 달하는 비활성화 효과를 보였으며, 헤파린 고분자를 도포한 결과에 비해 강한 염 저항성을 확인할 수 있었다. 이러한 결과로 미루어 보아 제조된 Hep-C는 AAV 바이러스 제거의 효과적 방법으로 충분한 가능성을 가짐을 증명하였다.

• 한국식품영양과학회지
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• 제34권1호
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• pp.8-12
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• 2005

본 연구는 약용 및 식용 식물로 사용되고 있는 쑥부쟁이 추출물과 분획물의 암세포 증식 억제 효과와 QR유도 효과를 실험하였다. 쑥부쟁이의 metanol 추출 및 용매 분획물의 암세포 증식억제 효과를 MTT assay로 실험한 결과, 3종의 인체 암세포주, 간암세포주인 HepG2, 자궁경부암 세포주인 HeLa 및 유방암 세포주인 MCF-7에서 모두 쑥부쟁이의 ethyl ether 분획층인 AYMEE층과 ethyl acetate 분획층인 AVMEA층에서 암세포 성장 저지 효과가 제일 컸다. 특히 HepG2 세포주에서 는 AYMEE를 200 $\mu$g/mL 첨가시켰을 때 94.5%의 암세포 증식 억제 효과가 나타났으며, 농도를 증가시킬수록 그 효과가 커져 500 $\mu$g/mL에서는 97.7%의 저지 효과를 보였다. MCF-7 세포주와 HeLa 세포주에서도 이와 비슷한 경향이었다. Butanol층인 AYMB와 메탄올층인 AYM에서는 대체적으로 낮은 농도에서는 효과가 약하였으나 300 $\mu$g/mL 이상에서는 높은 암세포 성장저지 효과를 보였다. HepG2 세포를 이용하여 암예방 지수인 QR 유도 활성을 측정한 결과, 다른 분획층에 비해 비극성 용매층인 hexane 분획층, AYMH에서 QR 유도 활성을 증가시키는 경향이었다.

• 대한한방내과학회지
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• 제22권1호
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• pp.87-93
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• 2001

A human hepatoma cell line, Hep G2 cells, is reliable for the study of alcohol-induced hepatotoxicity. The aim of this study is to determine the relationship between TNF-${\alpha}$, IL-$1{\alpha}$ production and EtOH-induced cytotoxicity on Hep G2 cells. The cells were incubated with EtOH in the presence of Artemisia Capillaris Herba(AC) for 24 hours and in the absence of AC for 48 hours. Cytoviability and cytokines release were analyzed by MTT assay and enzyme linked immunosorbent assay (ELISA), respectively. After 24 hours of EtOH exposure, the cytoviability had markedly decreased, and the release of cytokines had increased. The increased amount of cytokines contributed to EtOH-induced cytotoxicity. Anti-TNF-${\alpha}$ and IL-$1{\alpha}$ antibodies almost abolished it. Interestingly, EtOH-induced cytotoxicity and cytokines production were inhibited by AC. Moreover, when AC was used in combination with antibodies, there was a marked inhibition of EtOH-induced cytotoxicity. These results suggest that EtOH-induced cytotoxicity may regulate, by various factors, and AC may prevent the cytotoxicity through partial inhibition of the $TNF-{\alpha}$ and IL-$1{\alpha}$ secretion.