• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.99-110
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• 2015

The purpose of this study was to evaluate the inhibitory effects of commonly consumed vegetables in Korea on lipid accumulation and production of pro-inflammatory cytokines related to obesity/metabolic syndrome. Using KNHANES (Korea National Health and Nutrition Examination Survey) raw data ($1^{st}$; 1998, $5^{th}$; 2010, 2011) and a literature search, we selected vegetables for study. Edible portions of samples were prepared, ethanol-extracted, and then freeze-dried. 3T3-L1 adipocytes and HepG2 hepatocytes cells were used as in vitro models. Lipid accumulation determined by Oil-red O staining showed that all samples except bracken had inhibitory effects on lipid accumulation in 3T3-L1 adipocytes. Especially, crown daisy and mugwort effectively reduced accumulation of lipids, and their inhibition rates were more than 60% of the control group. Young pumpkin, leeks, crown daisy, and mugwort showed significantly decreased MCP-1 levels compared to the control group. However, adiponectin protein level did not increase in the vegetables experimental group. In HepG2 hepatocytes, all samples showed inhibitory effects on lipid accumulation at one of the two concentrations. Although adiponectin protein levels did not increase, MCP-1 protein levels decreased in adipocytes. Further, lipid accumulation in adipocytes and hepatocytes decreased. In conclusion, all samples showed one or more improved obesity/metabolic syndrome indicators. Among them, young pumpkin, leeks, crown daisy, and mugwort were selected as the most effective portions of vegetables based on improvement of obesity/metabolic syndrome-related indicators.

• Journal of Microbiology
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• v.37 no.2
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• pp.90-96
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• 1999

The core protein of the hepatitis C virus (HCV) is a multifunctional protein. The HCV core protein was reported to regulate cellular gene expression and transform primary rat embryo fibroblast cells. However, the role of the core protein in the pathogenesis of HCV-associated liver diseases is not well understood. To investigate the functional role of the core protein in cytophathogenicity, we have constructed stable expression systems of full length or truncated HCV core protein lacking the C-terminal hyderophobic domains and established HepG2 cell clones constitutively expressing the core protein. The full length core protein was localized in the cytoplasm and the C-terminal truncated core protein was localized in the nucleus. HepG2 cells expressing nuclear, truncated core protein showed elevated cell death during cultivation compared to untransfected cells and full length core-expressing cells. In the treatment with bleomycin, both cell clones expressing full length or truncated core protein appeared to be more sensitive to blemoycin than the parental HepG2 cells. These results suggest that the core protein may play a role in HCV pathogenesis promoting apoptotic cell death of infected cells.

• Toxicological Research
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• v.19 no.3
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• pp.235-240
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• 2003

The modification of CYP2E1 activity is of considerable interest because of its role in the metabolic activation of a variety of toxic chemicals. In the present studies, the time-course of changes in human CYP2E1 activities was determined after treatment with ethanol, glycerol, 4-methylpyrazole or isoniazid using intact HepG2 cells transfected by human CYP2E1. Hydroxylation of chlorzoxazone was chosen for the measurement of CYP2E1 activity. CYP2E1 protein levels were increased upon cultivation of cells in the presence of ethanol, glycerol, 4-methylpyrazole or isoniazid for 24 hr. After 24 hr cultivation, ethanol or glycerol increased CYP2E1 activities, whereas 4-methylpyrazole or isoniazid inhibited. This different effect of the chemical inducers on CYP2E1 activi-ties persisted to subsequent 24 hr. Competitive inhibition study suggested that 4-methylpyrazole or isoniazid has stronger binding affinity to CYP2E1 than ethanol or glycerol. These results demonstrate that different binding affinity of the chemical inducers to the active site of CYP2E1 plays important role in determining real CYP2E1 activity in intact cells after treatment with the chemical inducers. Present study would be helpful in precise understanding of human CYP2E1-mediated toxicity.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.1
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• pp.35-48
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• 1993

The in vitro predictive tests in cancer chemotherapy of cancer cell lines to anticancer drugs were determined using novel dye exclusion assay [NDEA], [3H] thymidine incorporation, and clonogenic assay [CA>. Antitumor effect of Bleomycin, Cis-platin, Vinblastine, Methotrexate to HEp-2, B16 cell lines using rapid assays was compared with [CA> in this study. In dye exclusion assay of B l6 cell line, cancer cells were sensitive to Bleomycin at all concentrations, to Vinblastine at the level of peak plasma concentration [PPC], ${\times}1/10$ [PPC](P<0.05). And Bleomycin revealed relatively good cytotoxicity than that of CDDP and vinblastine at ${\times}10$[PPC], (P<0.05). HEp-2 cells were resistive to methotrexate at the level of ${\times}100$[PPC] (P<0.05) In [3H] thymidine incorporation assay, B 16 cells were sensitive to Bleomycin, CDDP, Vinblastine at the level of [PPC], ${\times}10$ [PPC](P<0.01). Dose-dependent drugs of bleomycin, CDDP were more sensitive than Vinblastine at high concentration (P<0.05). In clonogenic assay, HEp-2 cell line was sensitive to three drugs of all concentrations except ${\times}10$ [PPC] of CDDP. B 16 cell line was sensitive to all drugs(P<0,01). In comparison of chemosensitivity tests among three assays, the results were correlated(${\gamma}=0.99$, P<0.05).

• Molecules and Cells
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• v.38 no.6
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• pp.518-527
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• 2015

Controlled release of medications remains the most convenient way to deliver drugs. In this study, we precipitated gold nanoparticles with quercetin. We loaded gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles (NQ) and tested the biological activity of NQ on HepG2 hepatocarcinoma cells to acquire the sustained release property. We determined by circular dichroism spectroscopy that NQ effectively caused conformational changes in DNA and modulated different proteins related to epigenetic modifications and c ell cycle control. The mitochondrial membrane potential (MMP), reactive oxygen species (ROS), cell cycle, apoptosis, DNA damage, and caspase 3 activity were analyzed by flow cytometry, and the expression profiles of different anti- and pro-apoptotic as well as epigenetic signals were studied by immunoblotting. A cytotoxicity assay indicated that NQ preferentially killed cancer cells, compared to normal cells. NQ interacted with HepG2 cell DNA and reduced histone deacetylases to control cell proliferation and arrest the cell cycle at the sub-G stage. Activities of cell cycle-related proteins, such as $p21^{WAF}$, cdk1, and pAkt, were modulated. NQ induced apoptosis in HepG2 cells by activating p53-ROS crosstalk and induces epigenetic modifications leading to inhibited proliferation and cell cycle arrest.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1086-1091
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• 2008

The antioxidant activities of the extracts of dangyuja (Citrus grandis Osbeck) leaves were evaluated. The highest phenolic content was obtained from the ethyl acetate fraction (EF) (202.1$\pm$0.8 mg GAE/g dried extract) and it exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The cytoprotective effects of EF on oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in a human hepatoma cell line, HepG2 cells, were investigated to understand the intracellular antioxidant mechanisms. Treatment of HepG2 cells with EF prior to oxidative stress was found to inhibit reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage in a dose-dependent manner. Gas chromatography-mass spectrometry (GC-MS) studies on EF resulted in tentative identification of 19 compounds representing 94.3% of the total content. Taken together, these results demonstrated that EF has excellent antioxidant activities and thus dangyuja leaves have great potential as a source for natural antioxidant which can be applied in food products.

• Biomedical Science Letters
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• v.18 no.2
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• pp.160-164
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• 2012

The baculovirus/insect cell expression system is of great value for the large-scale production of normal and mutant mammalian passive glucose-transport proteins heterologously for structural and functional studies. In most mammalian cells that express HepG2, this transporter isoform is predominantly located at the cell surface. However, it had been reported that heterologous expression of other membrane proteins using the baculovirus system induced highly vacuolated cytoplasmic membranes. Therefore, how a cell responds to the synthesis of large amounts of a glycoprotein could be an interesting area for investigation. In order to examine the subcellular location of the human HepG2 transport proteins when expressed in insect cells, immunofluorescence studies were carried out. Insect cells were infected with the recombinant baculovirus AcNPVHIS-GT or with wild-type virus at a MOI of 5, or were not exposed to viral infection. A high level of fluorescence displayed in cells infected with the recombinant virus indicated that transporters are expressed abundantly and present on the surface of infected Sf21 cells. The evidence for the specificity of the immunostaining was strengthened by the negative results shown in the negative controls. Distribution of the transporter protein expressed in insect cells was further revealed by making a series of optical sections through an AcNPVHIS-GT-infected cell using a confocal microscope, which permits optical sectioning of cell sample. These sections displayed intense cytoplasmic immunofluorecence surrounding the region occupied by the enlarged nucleus, indicating that the expressed protein was present not only at the cell surface but also throughout the cytoplasmic membranous structures.

• Toxicological Research
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• v.28 no.2
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• pp.117-122
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• 2012

Flavonoids, which form a major component in Houttuynia cordata Thunb., display a wide range of pharmacological activities. The expression of plant flavonoids is partly regulated by fermentation. Therefore, we studied the effects of fermentation on H. cordata in order to identify the strains present during the fermentation process, and to determine whether fermented H. cordata could be used as a probiotic. Our results showed that all 6 of the bacterial strains isolated from fermented H. cordata (FHC) belonged to the genus Bacillus. As expected, fermenting H cordata also increased the flavonoid content as increases were observed in the levels of rutin, quercitrin, and quercetin. To test the effects of fermentation, we treated LPS-stimulated RAW264.7 cells with non-fermented H. cordata extracts (HCE) or FHC extracts (FHCE). Compared to the HCE-treated cells, the FHCE-treated cells showed increased viability. No cytotoxic effects were detected in the FHCE-treated groups in the 2 cell lines used in the study, namely, RAW264.7 and RBL-2H3. FHCE-treated HepG2 cells showed decreased growth, compared to HCE-treated HepG2 cells. These results indicate that the fermented H. cordata predominantly contained Bacillus strains. Furthermore, FHCE are able to prevent LPS-induced inflammatory effects and inhibit the growth of HepG2 cells.

• Toxicological Research
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• v.23 no.1
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• pp.25-31
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• 2007

To evaluate the protective effect of Houttuynia cordata on hydrogen peroxide-induced oxidative DNA damage in HepG2 cell line, we used an alkaline single-cell gel electrophoresis (SCGE; comet assay). The DNA damage was analyzed by tail moment (TM) and tail length (TL), which used markers of DNA strand breaks in SCGE. The $100{\mu}g/ml$ of methanolic extract of Houttuynia cordata root showed significant protective effects (p < 0.01) against hydrogen peroxide-induced DNA damage in HepG2 cells and increased cell viability against hydrogen peroxide. The results of this study indicate that Houttuynia cordata root methanol extract acts as a potential antioxidant, and exhibits potential anticancer properties, which may provide a clue to find applications in new pharmaceuticals for oxidative stability.

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.22-30
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• 2008

Malachite Green (MG), a toxic chemical used as a dye, topical antiseptic and antifungal agent for fish, is highly soluble in water, cytotoxic to various mammalian cells and also acts as a liver tumor promoter. In view of its industrial importance and possible exposure to human beings, MG possesses a potential environmental health hazard. So, we performed with HepG2, a human hepatocellular carcinoma cell line, to identify the differentially expressed genes (DEGs) related to toxicity of MG. And we compared gene expression between control and MG treatment to identify genes that are specifically or predominantly expressed by employing annealing control primer (ACP)-based $GeneFishing^{TM}$ method. The cytotoxicity $(IC_{20})$ of MG was determined above the $0.867{\mu}M$ in HepG2 cell for 48 h treatment. And the DEGs of MG were identified that 5 out of 6 DEGs were upregulated and 1 out of 6 DEGs was down-regulated by MG. Also, MG induced late apoptosis and necrosis in a dose dependent in flow cytometric analysis. Through further investigation, we will identify more meaningful and useful DEGs on MG, and then can get the information on mechanism and pathway associated with toxicity of MG.