• Journal of Life Science
• /
• v.19 no.12
• /
• pp.1731-1736
• /
• 2009

Recent studies determined that a chronic western-style diet increased the endogenous small heterodimer partner (SHP) protein levels in mice. In experiments with cell cultures, chenodeoxy cholic acid (CDCA) treatment increased endogenous SHP protein levels and reduced the degradation rate of exogenously expressed flag-SHP levels in the human hepatoma cell line, HepG2 cells. In addition, bile acid-induced intestinal fibroblast growth factor-19 (FGF-19) increased the half-life of the exogenously expressed SHP when HepG2 cells were transfected with ad-flag-SHP. However, both the expression level and the degradation rate of the endogenous SHP in response to cholic acid and FGF-19 have not been well understood, either in mice or in cultured HepG2 cells. This study examined the effects of cholic acid treatment on the endogenous SHP protein levels in mice and the effects of FGF-19 on the degradation rate of the endogenous SHP protein in HepG2 cells. Mice fed 0.5% cholic acid in normal chow showed an increase in endogenous SHP protein levels during both 12 hr and 24 hr treatment periods as compared to control mice fed only normal chow. In cultured HepG2 cells, treatment with CDCA did not noticeably change the rate of degradation in the endogenous SHP protein from cells not treated with CDCA. Although consistent with the previous studies on the exogenous ad-flag-SHP protein, treatment with FGF-19 significantly decreased the degradation rate of the endogenous SHP protein when HepG2 cells were treated with cyclohexamide. These results suggest that both bile acids and FGF-19 increase the endogenous SHP protein levels in mouse liver and HepG2 cells.

• Journal of Life Science
• /
• v.21 no.7
• /
• pp.1046-1051
• /
• 2011

Diallyl disulfide (DADS), the most prevalent oil-soluble organosulfur compound in garlic, is known to have diverse biological activities, including anticarcinogenic, antiatherosclerotic, antiinflammatory, and antioxidant actions. In this study, we investigated the effect of DADS on the expression of heme oxygenase-1 (HO-1) in human liver hepatoma cell line HepG2. Treatment of HepG2 cells by DADS evoked a dose-dependent growth inhibition without significant toxicity to the cells, and also induced the expression of transcription factor Nrf2. However, DADS did not have any enhancing effect on transcription and translation of HO-1 expression in HepG2 cells. In addition, DADS efficiently blocked protein synthesis of HO-1 in HepG2 cells stimulated by CoPP or hemin. But, DADS did not decrease the content of transcripts of HO-1 gene stimulated by CoPP, with accumulation of Nrf2 and small Maf in the nucleus. Based on these results, we conclude that DADS inhibits HO-1 expression by modulation of translational level of CoPP or hemin-induced HO-1 expression in HepG2 cells.

• Journal of the Korean Chemical Society
• /
• v.59 no.1
• /
• pp.22-30
• /
• 2015

The effect of diphtheria toxin on cell membrane lipids was studied by examining the phospholipase D (PLD) activity and free fatty acids (FFA) release in HepG2 cells. The diphtheria toxin effects on lipid alteration show apparently maximal at pH 5.1, stimulating PLD activity nearly 3.5 fold and enhancing FFA release approximately 5 fold over the control. These results indicate that the membrane is perturbed and its lipid component is rearranged during the diphtheria toxin translocation. Digitonin, a random membrane perturbing detergent, exhibit about four-fold higher perturbation effect over the diphtheria toxin at neutral pH. This observation suggests that the membrane perturbation induced by diphtheria toxin appears to be rather selective. To investigate the cause of the membrane perturbation, Cibacron blue, an inhibitor of membrane pore formation, and hemagglutinin, an influenza virus with fusion peptide, were tested for their effects on diphtheria toxin action. Cibacron blue decreased the diphtheria toxin effect by almost 50%, but the lipid alteration induced by hemagglutinin was similar to the diphtheria toxin effect. These observations imply that the membrane perturbation induced by diphtheria toxin may be caused by a combination of pore formation and insertion of hydrophobic peptide of toxin to the membrane as well. Additionally, we found that the diphtheria toxin increased the HepG2 cells permeability but the cells viability was maintained at high level at the same time. DNA fragmentation which is related to apoptosis was not induced by the toxin. Under these conditions, we could demonstrate that the lipid alteration of HepG2 cells was brought about by diphtheria toxin at acidic pH.

• Applied Biological Chemistry
• /
• v.49 no.4
• /
• pp.270-275
• /
• 2006

[ $2{\beta},\;3{\alpha}$ ], 23-trihydroxyrus-12-ene-28-oic acid was isolated from Trapa pseudoincisa S. et Z. It has a common structure of pentacyclic triterpenes and belongs to the amyrin ursolic acid group. The cytotoxic effect of this compound was investigated in human hepatoma cell line HepG2. $2{\beta},\;3{\alpha}$, 23-trihydroxyrus-12-ene-28-oic acid showed dose-dependent cytotoxicity in HepG2 cells. Confocal microscopy data showed that green fluorescence was increased in $2{\beta},\;3{\alpha}$, 23-trihydroxyrus-12-ene-28-oic acid treated-HepG2 cells in a time-dependent manner. $2{\beta},\;3{\alpha}$, 23-trihydroxyrus-12-ene-28-oic acid also increased the sub-G1 cell population of HepG2 cells as well as ladder-like DNA fragmentation. Taken together, our results indicate that $2{\beta},\;3{\alpha}$, 23-trihydroxyrus-12-ene-28-oic acid induced apoptosis in HepG2 cells.

• Journal of Life Science
• /
• v.28 no.2
• /
• pp.176-186
• /
• 2018

In this study, the total polyphenol contents, antioxidant activities and anti-proliferation effects of HepG2 cell lines in organic slovent fractions obtained from the main methanolic extract of P. yezoensis were analyzed. The polyphenol content of the $CHCl_3$ fraction was $10.3{\mu}g/mg$, slightly less than $13.08{\mu}g/mg$ of the water fraction, but $ED_{50}$ estimated by measuring DPPH free radical scavenging activity exhibited the highest $16.96{\mu}g/ml$ in the $CHCl_3$ fraction. The proliferation effects of $CHCl_3$ and EtOAc fraction toward HepG2 cells inhibited in a dose-dependent manner, showed 90% inhibition when treated for 24 hr at $900{\mu}g/ml$ of $CHCl_3$ fraction. Meanwhile gene expression patterns in HepG2 cells treated $50{\mu}g/ml$ of $CHCl_3$ fraction were identified with microarray analysis. Concerning the efficacy of P. yezoensis, gene ontology analysis explored the genes associated with response to molecule of bacterial origin, vitamin D metabolic process, and response to nutrient. Thus IL6R, CYP1A1 were selected as significant genes based on expression patterns of HepG2 cells, and pathway analysis indicates that ARNT might be considered as a upstream regulator. Also, expression analysis of IL6R and CYP1A1, activity of upstream regulator ARNT in HepG2 cells was confirmed based on Western blotting analysis at the protein level after being treated with 50 and $100{\mu}g/ml$ of $CHCl_3$ fraction.

• Journal of Life Science
• /
• v.13 no.3
• /
• pp.324-332
• /
• 2003

The objective of this study was to examine if transient transfection of CAR can transactivate CYP2B1 PBRU reporter gene in COS cells in which the endogenous CYP2B1 gene is not induced by PB. In non-transfeced cells of both Hep G2 and COS, the endogeneous expression of CAR was not detected by antibody against CAR. When cultured cells were transfected with CAR expression plasmid, mCAR1-GFP, both cell types expressed high levels of CAR protein and could allow to examine the effect of CAR in PBRU transactivation. Both cell types expressed endogenous RXR and transfection of RXR expression plasmid dramatically increased its protein expression. Whereas CAR transactivated PBRU2C1Luciferase about 12 fold as compared to 2C1Luciferase in Hep G2 cells, it did not stimulate the luciferase activity of the PBRU reporter gene in COS cells. These results indicate that Hep G2 cells can respond to CAR differently from COS cells, and suggest that factors other than CAR and RXR may be required in inducing PBRU activation and the expression of these factors may be different between liver and kidney.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.2
• /
• pp.329-332
• /
• 2002

We investigated the effect of Sarcodon aspratus extract on expression of cell cycle regulators. Methanol extract of Sarcodon aspratus showed a growth suppression on HepG2. As shown by western blot analysis, the expressions of cyclin A and Dl known as cell cycle regulators were decreased after treatment of Sarcodon aspratus extract. On the other hand, the expression of cyclin Bl was increased in the presence of Sarcodon aspratus extract. Furthermore, the expression of p53, a tumor supressor gene, and p27, a cell cycle dependent protein kinase inhibitor, were increased, whereas the expression of PCNA was decreased. In conclusion, our study suggests that growth inhibitory effect of Sardodon aspratus methanol extract on HepG2 is induced by cell cycle arrest in the Gl phase caused by decrease in cyclin A, Dl expressions and increases in p53, p27 expression.

• Journal of Life Science
• /
• v.28 no.1
• /
• pp.50-57
• /
• 2018

Millettia erythrocalyx, a species of plant in the Fabaceae family, is widely distributed in the tropical and subtropical regions of the world, such as the Indies, China, and Thailand. The antiviral activity of flavonoids from M. erythrocalyx has been reported; however, the antioxidative and anticancer activities of M. erythrocalyx remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extract of M. erythrocalyx (EEME) and the molecular mechanism of its anticancer activity in human hepatocellular carcinoma HepG2 cells. EEME exhibited significant antioxidative effects, with a concentration at 50% inhibition ($IC_{50}$) value of $2.74{\mu}g/ml$, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; moreover, it inhibited cell proliferation in a dose-dependent manner in HepG2 cells. Cell cycle analyses showed that EEME induced HepG2 cell accumulation in the subG1 phase in a dose-dependent manner. EEME also induced apoptosis of HepG2 cells, with increases in apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. Treatment with EEME resulted in increased expression of First apoptosis signal (Fas), a death receptor, and Bcl-2-associated X protein (Bax), a proapoptotic protein, and the activation of caspase-3, 8, and 9, resulting in the cleavage of poly (Adenosine diphosphate-ribose) polymerase (PARP). Collectively, these results suggest that EEME may exert an anticancer effect in HepG2 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Journal of Haehwa Medicine
• /
• v.4 no.1
• /
• pp.211-223
• /
• 1995

The antitumor effect of 柴胡(Bupleuri Radix : BP), 茵陳(Artemisiae capillaris Herba; ACH) 및 蒲公英(Taraxaci Herba; TH) and 蒲公英 EE層(Ethyl ether layer of TH; EETH) on human hepatocytes such as Hep G2, PLC and Hep 3B, and synergistic action with the anticancer drugs, that is, mitomycin(MMC), cisplatin(CPT) and 5-fluorouracil(5-FU) were studied by the method of MTT. The results were obtained as follows: 1. $IC_{50}$ against Hep G2, PLC and Hep 3B was $15.5{\mu}g/ml$, $25.4{\mu}g/ml$ and 31.25 in MMC, $92.5{\mu}g/ml$, $50.2{\mu}g/ml$ and $62.5{\mu}g/ml$ in CPT and $125{\mu}g/ml$ in 5-FU respectively. 2. Cytotoxic effect on Hep G2 was obvious in BP-treated group, synergistic action was most effective in TH-treated group or with MMC. 3. Cytotoxic effect on Hep 3B was obvious in ACH-treated group, synergistic action was most effective in ACH-treated group or with MMC. 4. Cytotoxic effect on PLC was obvious in ACH-treated group, synergistic action was most effective in TH-treated group or with MMC. From above results it was concluded that ACH showed the best antitumor effect against PLC and Hep 3B, BP aganst Hep G2 and also synergistic effect was most effective with MMC, which indicates that it is necessary to seperate the antitumor substances in ACH.

• Food Science of Animal Resources
• /
• v.24 no.3
• /
• pp.293-297
• /
• 2004

This study was carried out to investigate the antitumor activity from sulfur fed duck. The antitumor substances were crude purified by solvent extraction, silica gel column chromatography, and HPLC using C18 column. In MTT assay, the active compounds exhibited more cytotoxic activity on tumor cell lines than normal cell line. In addition of 100 $\mu\textrm{g}$/mL concentrations of crude purified active compounds, the growth inhibition rate of tumor cell lines was 56% (Hep-2j human larynx), 58% (KB; human epidermoid of mouth carcinoma), and 28% (MDBK; bovine normal kidney), respectively. The survival rate of clonogenic assay was 26% in Hep-2 and 28% in KB at 200 $\mu\textrm{g}$/mL.