• Applied Biological Chemistry
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• 제40권6호
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• pp.577-582
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• 1997

감귤류에 포함되어있는 성분중, 생리활성물질로 거론되어지고 있는 citrus flavonoid 즉, hesperidin, hesperetin, naringin 및 naringenin 4종류를 가지고 간장triglyceride합성의 율속효소로 알려져 있는 phosphatidate phosphohydrolase 활성에 대하여 in vitro계에 미치는 영향과 이들 flavonoid가 HepG2 세포의 생존율 및 증식에 미치는 영향에 대해서도 함께 검토하였다. 그 결과 본 실험에 사용된 모든 flavonoid 는 $10{-4}M$ 농도까지는 세포생존율 및 증식이 최고에 도달하였으나, $10{-3}M$ 농도에서 aglycone flavonoid는 현저한 저해효과를 나타냈다. naringin 및 hesperidin의 glycoside flavonoid는 첨가한 모든 농도에서 PAP활성을 촉진시키는 경향을 나타내었다. 그러나, aglycone flavonoid인 hesperetin은 PAP활성을 농도 의존적으로 저해하였으며, naringenin은 $10{-2}M$ 농도에서 강한 저해효과를 나타내었다. 이러한 결과로 미루어 볼 때 aglycone flavonoid가 생체내에서 세포 생존율, 증식 및 지질대사에 강한 영향을 미칠 것으로 생각되어진다.

• Toxicological Research
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• 제22권1호
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• pp.23-30
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• 2006

Among poly aromatic hydrocarbons, dioxin and PCBs are the most controversial environmental pollutants in our modern life. These pollutants are known as human carcinogens, and liver is the most sensitive target in animal cancer models. Specific aims of the study were focused on the mechanism of carcinogenesis in hepatocytes and the structure-activity relation among these diverse environmental chemicals. Because key mechanisms of dioxin-induced carcinogenesis in human epithelial cell model are the alteration of signal transduction pathway and PKC isoforms, the alteration of the signal transduction pathways and other factors associated with carcinogenesis were studied. Rat hepatocytes cultured under the sandwich protocols were exposed with the various concentration of dioxins and PCBs, and signal transduction pathway, protein kinase C isoforms, oxidant stress, and apoptotic nuclei were evaluated. Since it is important to understand the structure-activity relation among these chemicals to properly assess the carcinogenic potentials, the study analyzed the parameters associated with carcinogenic processes, based on their structural characteristics. In addition, signal transduction pathways and PKC isoforms involved in inhibition of UV-induced apoptosis were also analyzed to elaborate the tumor promotion mechanism of these chemicals. Induction of apoptosis by UV irradiation was optimal at $60\;J/m^2$ in primary hepatocyte in culture. Compared to non coplanar PCBs such as PCB 114 and PCB 153, coplanar PCBs such as PCB 77 and PCB126 showed a stronger inhibition of apoptosis induced by UV irradiation. Production of reactive oxygen species (ROS) was more stimulated by non-coplanar PCBs than coplanar PCBs with the most potent induction of ROS by chlorinated non-coplanar PCB. As compared to the level of induction by PCB126, non-coplanar PCB153 showed a higher increase of intracellular concentrations. Besides the alteration of intracellular calcium concentration, translocation of PKC from cytosolic fraction to membrane fraction was clearly observed upon the exposure of non-coplanar PCB. Taken together, the present study demonstrated that there is a potent structure-activity relationship among PCB congeners and the mechanism of PAH-induced carcinogenesis is structure-specific. The study suggested that more diverse pathways of PAH-induced carcinogenesis should be taken into account beyond the boundary of Ah receptor dogma to assess the health impact of PAH with more accuracy.

• Applied Biological Chemistry
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• 제49권3호
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• pp.233-237
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• 2006

Sprague-Dawley 랫트(실험용 쥐)에서 간을 적출하여 Collagen coating된 세포 배양 접시에 간세포 배양을 하여 친환경 재배 배 추출물과 일반 관행 재배 배 추출물의 간세포 기능성을 분석하였다. 3일간 적응 시킨 후 관행 재배 배 추출물과 친환경 재배 배 추출물을 농도 별(동결 건조된 $5\;{\mu}g/ml$, $20\;{\mu}g/ml$, $40\;{\mu}g/ml$) 처리하여 간세포의 에너지원인 ATP assay를 실시한 결과 관행 재배 배 추출물의 경우는 대조군과 유의한 차이는 인정이 되지 않았으나 친환경 재배 배 추출물의 경우 농도 의존적으로 정상군에 비해 180%까지 증가하는 것으로 나타났다. 한편 세포 성장의 경우도 DNA의 특유 염기 구성성분중의 하나인 thymine의 전구체인 $[^3H]$-thymidine을 간세포에 처리하여 DNA 합성을 알아본 결과 친환경 재배 배 추출물 을 농도별로 처리하였을 때 관행재배 배 추출물에 비해 간세포의 세포 성장율이 증가하는 것으로 나타났다($40\;{\mu}g/ml$ 투여 시 관행 재배 배추출물 112% vs. 친환경 재배 배 추출물은 234%; p<0.05). 아울러 세포성장 단백질인 CDK-2, CDK-4의 경우도 친환경 배 추출물 처리 시 현저하게 증가하는 것으로 나타났으며 세포성장 억제 단백질인 p21WAF1/Cip1 및 p27 Kip1의 경우는 억제시키는 것으로 나타났다.

• 생명과학회지
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• 제13권4호
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• pp.541-550
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• 2003

본 실험에서는 C형 간염바이러스 (HCV)의 외피 단백질인 E2 당단백질에 결합하는 세포단백질들을 클로닝하기 위해 간세포 cDNA를 phage 표면에 발현시킨 phage library를 제작하였고, 12-mer peptide library와 함께 E2 단백질에 대해 panning을 실시하였다. 검색결과 세포내 신호전달과 cytoskeleton 구성에 관여하는 tensin, membrane protein band 4.1 등 세포질내 단백질과 CCR7, CKR-L2, insulin-like growth factor-1 receptor 등 세포막 단백질 등이 확인되었다. 이들 단백질들을 발현하는 phage들은 수용성 E2단백질을 이용한 결합중화반응 결과 E2 단백질에 특이적으로 결합함이 확인되었다. 사람 T 세포에서 주로 발현되는 CCR7 유전자를 PHA로 활성화된 사람 T 세포의 total RNA를 이용하여 증폭하고 클로닝하였다. 293T 세포에 transfection시켜 단백질 발현양상을 flow cytometer로 분석하여 70% 이상의 세포들이 CCR7을 발현하고 있음을 관찰하였다. 수용성 E2 단백질을 CCR7이 transfection된 세포와 mock transfection된 대조군 세포에 각각 반응시킨 결과 dose-dependent 양상으로 CCR7에 결합하였다.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.1983-1988
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• 2012

Stem cell transplantation is emerging as a possible new treatment for liver cirrhosis, and recent animal studies have documented the benefits of stem cell therapy in a hepatic fibrosis model. However, the underlying mechanism of stem cell therapy is still unclear. Among the proposed mechanisms, the cell replacement mechanism is the oldest and most important, in which permanently damaged tissue can be replaced by normal tissue to restore function. In the present study, Cy5.5-labeled superparamagnetic iron oxide (SPIO) was used to label human mesenchymal stem cells. The uptake of fluorescently labeled nanoparticles enabled the detection and monitoring of the transplanted stem cells; therefore, we confirmed the direct incorporation and differentiation of SPIO into the hepatocyte-like transplanted stem cells by detecting human tyrosine aminotransferase (TAT), well-known enzymatic marker for hepatocyte-specific differentiation.

• Journal of Ginseng Research
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• 제43권4호
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• pp.539-549
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• 2019

Background: 20(S)-Protopanaxadiol (PPD), the aglycone part of 20(S)-protopanaxadiol ginsenosides, possesses antidepressant activity among many other pharmacological activities. It is currently undergoing clinical trial in China as an antidepressant. Methods: In this study, an ultra-performance liquid chromatography coupled with triple quadrupole time-of-flight mass tandem mass spectrometry method was established to identify the metabolites of PPD in human plasma and urine following oral administration in phase IIa clinical trial. Results: A total of 40 metabolites in human plasma and urine were identified using this method. Four metabolites identified were isolated from rat feces, and two of them were analyzed by NMR to elucidate the exact structures. The structures of isolated compounds were confirmed as (20S,24S)-epoxydammarane-12,23,25-triol-3-one and (20S,24S)-epoxydammarane-3,12,23,25-tetrol. Both compounds were found as metabolites in human for the first time. Upon comparing our findings with the findings of the in vitro study of PPD metabolism in human liver microsomes and human hepatocytes, metabolites with m/z 475.3783 and phase II metabolites were not found in our study whereas metabolites with m/z 505.3530, 523.3641, and 525.3788 were exclusively detected in our experiments. Conclusion: The metabolites identified using ultra-performance liquid chromatography coupled with triple quadrupole time-of-flight mass spectrometry in our study were mostly hydroxylated metabolites. This indicated that PPD was metabolized in human body mainly through phase I hepatic metabolism. The main metabolites are in 20,24-oxide form with multiple hydroxylation sites. Finally, the metabolic pathways of PPD in vivo (human) were proposed based on structural analysis.

• 미생물학회지
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• 제47권4호
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• pp.342-347
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• 2011

인체의 바이러스 감염 방어기전에서 T 림프구는 중요한 역할을 한다. 하지만, 만성 C형 간염 바이러스의 일차적 복제장소인 간염 환자의 간에서 분리된 HCV 특이 T 림프구는 심각한 기능결핍을 보인다. 이러한 T 림프구 기능결핍의 이유로는 PD-1, CTLA-4 등 면역억제 물질의 발현, 또는 간에서 특이적으로 유도되는 면역내성(immune tolerance)이 있으나, 간세포(hepatocytes)와 HCV 특이 T 림프구의 상호작용에 대해서는 명확하게 확립되어 있지 않다. 따라서 본 연구에서는 HLA(human leukocyte antigen) A2+ 간암세포주(human hepatoma cell line; huh7.5)가 항원제시(antigen presentation)를 통해 효과적으로 HCV 특이 T 림프구를 활성화시키며 간암세포주(huh7.5) 표면의 PD-L (program death ligand) 1 발현은 T림프구의 활성을 감소시켜 면역조절의 가능성이 있음을 시사하였다. 또한, HCV 특이 tetramer 반응은 T 림프구의 과도한 활성으로 자기사멸(apoptosis)의 경로에 있음을 caspase 3 활성으로 확인하였고, 역시 PD-L1의 발현이 T 림프구를 자기사멸(apoptosis)로부터 구제하여 caspase 3 활성이 감소하는 것을 확인하였다. 이는 PD-L1과 간성(liver) T 림프구 표면의 PD-1 결합이 T 림프구의 자기사멸을 막고, 또한 그 기능을 회복시켜 만성 C형 간염 치료에 응용될 수 있음을 시사한다.

• Advances in Traditional Medicine
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• 제6권3호
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• pp.167-173
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• 2006

A growing body of evidence supports lipid peroxidation as having a role in the pathogenesis of liver disease. Although the probable cause of damage to human hepatocytes may be multifactorial, free radicals have been implicated in a variety of liver diseases, particularly in the presence of iron overload and toxic substances such as ethanol. Consequently, antioxidants, particularly those of plant origin such as flavonoids, may help to reduce the risk of developing these diseases. Silybum (S.) marianum, a medicinal plant widely used in traditional European medicine for the treatment of liver disorders, was evaluated for antioxidant activity. Thin layer chromatography and High Performance Liquid Chromatography analyses of crude extract of the plant confirmed the presence of a number of flavonoids reported in the literature. The antioxidant activity of these flavonoids was measured through inhibition of lipid peroxidation and 1, 1-diphenyl-2- picrylhydrazyl radical scavenging. The crude plant extract showed marked antioxidant activity in both assays. These results suggest that S. marianum contains flavonoids with antioxidant activity, capable of inhibiting or scavenging free radicals, thus supporting its traditional use as a hepatoprotective agent.

• 대한본초학회지
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• 제23권3호
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• pp.149-154
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• 2008

Objectives : The purpose of this study is to investigate the biological Effect of multi-herbal drug 'KOCO-P1' on human hepatocyte HepG2 cells. Methods : Multi-herbal drug 'KOCO-P1' was composed of Ginseng Radix, Astragali Radix, Polygonati Rhizoma, Liriopis Tuber, and Scrophulariae Radix. Cytotoxicity and cytoprotective activity of KOCO-P1 was verificated by MTT assay. And antioxidative effect of KOCO-P1 against EtOH, Nicotine was inspected by Hydroperoxide assay. Results : KOCO-P1 showed no cytotoxicity on HepG2 cells for 24, 48 hours. KOCO-P1 at 50 ${\mu}g/mL$ reduced the production of H2O2 in HepG2 cells by EtOH. KOCO-P1 at 50 ${\mu}g/mL$ reduced the production of $H_2O_2$ in $HepG_2$ cells by Nicotine. Conclusions : KOCO-P1 at the low concentration could be supposed to have antioxidative effect on human hepatocyte with no cytotoxicity.

• Biomolecules & Therapeutics
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• 제23권5호
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• pp.486-492
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• 2015

Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their interassay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.