• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.360-360
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• 1998

C11, a chloride-containing VK3 analog, acts as a mediator of programmed cell death in SK-Hep-1 cell lines, but its molecular mechanisms linked to cell death are not understood. In this study, we investigated the expression of p21 gene and its relationship to apoptosis induced by C11. In SK -hep-1 cells, the addition of C11 resulted in time-dependent growth suppression and DNA fragmentation characteristics of apoptosis. p21 protein was induced during this process, while the protein level of p53 was not changed at the same condition. This apoptotic cell death with p21 induction was also observed in the Hep3B cells lacking functional p53 after treatment of C11. These results suggest that C11-induced apoptosis is associated with up-regulation of p21 protein in p53-independent pathway. Next, in order to confirm whether the p53-independent p21 induction is required for C11-induced apoptosis, we introduced the p21 gene into Hep3B. Overexpression of p21 did not affect the expression of the bcl-2 gene, but DNA fragmentation and PARa cleavage were significantly increased. These data indicate that p21 is involved in C11-induced apoptosis. Although Bcl-2 has been implicated to interfere with an essential signaling molecule involved in the apoptosis pathway, its molecular mechanism and target molecule are poorly understood. To determine the effects of bcl-2 overexpression on apoptosis and to investigate whether BcI-2 interfers with the p53-independent p21 pathway, we transfected the bcl-2 expression vector into SK - Hep-1 cels. Overexpression of Bcl-2 prevented C11-induced apoptosis. Taken together, C11-induced apoptosis is regulated by p52-independent p21 pathway and bcl-2 may inhibit functional activity of p21, therebe may inhibit the C11-induced apoptosis.ptosis.

• The Journal of Korean Medicine
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• v.37 no.1
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• pp.62-76
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• 2016

Objectives: The goal of this study was to investigate the anti-lipogenic effects of Samhwangsasim-tang(SHT), Daehwanghwangryunsasim-tang(DHT) aqueous extract on HepG2 cells with palmitate. Materials and Methods: HepG2 cells treated with palmitate were used in this study as hepatic steatosis model. Cells were treated with different concentrations of SHT, DHT aqueous extract for 24 hours. Cell viability and cytotoxicity were analyzed by MTT assay. Expressions of Bcl-2, Bax, Survivin, P21, TGF-${\beta}1$, LXR-${\alpha}$, ChREBP, ACC1, SCD1 mRNA were determined by Real-time PCR. Apoptosis of cells was detected by ELISA and FACS. Expression level of caspase-3 was studied by Western blot. Lipid accumulation was indicated by Oil Red O staining. Results: SHT, DHT aqueous extract had no cytotoxicity, but decreased palmitate-induced lipid accumulation in HepG2 cells. SHT aqueous extract suppressed fatty acid synthesis by inhibiting LXR-${\alpha}$, ChREBP, SCD1 activation and increasing TGF-${\beta}1$ expression level. DHT aqueous extract also suppressed fatty acid synthesis by decreasing ChREBP expression and increasing TGF-${\beta}1$ expression. Apoptosis of lipid accumulated cells was increased by enhanced activities of P21, caspase-3 and inhibited expressions of Bcl-2, Survivin. Conclusions: These results suggest that SHT and DHT have an anti-lipogenic effects on lipid accumulation of hepatic cell. Also SHT and DHT have an efficacy to increase apoptosis of adipocyte without cytotoxicity. Therefore, SHT and DHT might have potential clinical applications for treatment of hepatic steatosis.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1232_1233
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• 2009

Paraquat is well-known to cause hepatotoxic responses in human and other mammal species. In solution, it forms free radicals and charge-transfer complex of which formation plays an important role in determination of its biological activity in the presence of various anions. The HepG2 cells were cultured onto a quartz crystal sensor which is possible to detect the density and a viscosity changes using the resonance frequency (F) and the resonance resistance (R). The plot of F-R diagram is able to explain the rheological change of cells onto the surface of the quartz crystal sensor. In this paper, we investigated the physical properties of the HepG2 cells cultured onto a ITO electrode of the quartz crystal sensor according to the paraquat injection at various concentrations (100 mM, 10 mM, 1 mM). We also observed the morphological changes with a micro CCD camera, simultaneously. The HepG2 cells were cultured onto the ITO electrode surface of the quartz crystal modified a collagen film in $CO_2$ incubator. After the paraquat injection, we observed the changes of the morphologies by the micro CCD camera depending on time and analyzed the physical changes of cells on the electrode surface of quartz crystal using F-R diagram. From all results, we proved the effect of paraquat at various concentrations which is led to an apoptosis such as weakening and death of the cells by oxidation and reduction reaction that were produced the superoxide anions and other free radicals.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1310-1316
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• 2005

To evaluate the toxicological properties of human cytochrome P450 2E1 (CYP2E1) induced by ethanol and possible protective effects of various green tea catechins on alcohol-induced toxicity, transfected HepG2 cells that stably and constitutively express human CYP2E1 were established using the recombinant retroviral expression vector. Exposure of the CYP2E1-expressing HepG2 cells to high concentration of ethanol (200 mM) for 5 days resulted in a more than $50\%$ increase of cytotoxicity, assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and reactive oxygen species (ROS) production, and loss of normal morphology, in comparison with HepG2 cells containing control vector. Treatment of the cells with various catechins increased cell viability by more than 2-fold. (-)-Epicatechin gallate and(-)-catechin gallate at the lowest concentration ($5\;{\mu}M$) attenuated cell death induced CYP2E1 by $60-65\%$. Therefore, the results showed that the catechins, including epimerized catechins, have strong protective effects against alcohol-induced CYP2E1 toxicity, and it is correlated with antioxidant effect.

• Herbal Formula Science
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• v.15 no.2
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• pp.139-145
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• 2007

The purpose of this study was to investigate the anti-oxidant effect of Cynomorium songaricum. The extract of Cynomorii Herba was studied for diphenyl-picryl-hydrazyl (DPPH) radical scavenging activity, HepG2 cell viability and $H_2O_2$-induced cytotoxicity by a modified MTT assay. DPPH radical scavenging activity was measured after 30 minutes. The extract was tested by 1. 5, 10, 50, 100 and 500 ${\mu}g/ml$ concentrations. HepG2 cell viability by a modified MTT assay was measured in the concentrations of 10, 50, 100, 250, 500 ug/ml for 24 h. The results showed that the extract scavenged DPPH radical up to 52.2% with 50 ug/ml concentration. The extract did not reduced the cell viability and $H_2O_2-induced$ cytotoxicity (69.4%) was blocked by the extract in the concentrations of 50, 100, 250 and 500 ${\mu}g/ml$. In conclusion, the extract of Cynomorii Herba has potent antioxidant activity.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.236-245
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• 2018

Ingredients of soy and fermented soy products have been widely utilized as food supplements for health-enhancing properties. The aim of this study was to evaluate the effects of fermented soymilk (FSM) and soymilk (SM) on free fatty acid-induced lipogenesis in the hepatocellular steatosis model. HepG2 cells were incubated with palmitic acid (PA) for 24 h to induce lipogenesis and accumulation of intracellular lipid contents. The PA-treated cells were co-incubated with FSM, SM, genistein, and estrogen, respectively. Lipid accumulation in the PA-treated HpG2 cells was significantly decreased by co-incubation with FSM. Treatment of HepG2 cells with PA combined with genistein or estrogen significantly increased the expression of SREBP-1. However, FSM co-incubation significantly attenuated SREBP-1 expression in the PA-treated HepG2 cells; in addition, expression of NRF-2 and phosphorylation of ERK were significantly increased in the PA and FSM co-incubated cells. PA-induced ROS production was significantly reduced by FSM and SM. Our results suggested that the bioactive components of FSM could protect hepatocytes against the lipid accumulation and ROS production induced by free fatty acids. These effects may be mediated by the inhibition of SREBP-1 and the activation of NRF-2 via the ERK pathway in HepG2 cells.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4919-4923
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• 2014

Background: To investigate the effect of celecoxib on telomerase activity and apoptosis in a human laryngeal squamous carcinoma cell line (Hep-2 cells). Materials and Methods: The growth inhibition rate of Hep-2 cells in vitro was measured by MTT assay, and apoptosis by TUNEL assay and flow cytometry (FCM). The TRAP-ELISA method was used to determine telomerase activity in Hep-2 cells. The mRNA expression of human telomerase RNA component(hTR), human telomerase reverse transcriptase (hTERT) and human telomerase-associated protein(hTEP1) was determined by RT-PCR assay. Expression of Bax and Bcl-2 proteins was assessed by Western blotting. Results: Celecoxib can inhibit proliferation and induce apoptosis in a dose- and time-dependent manner, repress telomerase activity, decrease hTERT mRNA and Bcl-2 protein expression and increase Bax protein expression, PGE2 had no effect on telomerase. Conclusions: Celecoxib had the antiproliferative and pro-apoptotic effect in Hep-2 cells. Apoptosis was accompanied by a decrease in telomerase activity which was directly correlated with hTERT mRNA and up-regulation of Bax/Bcl-2. Bcl-2 may thus play an important role in telomerase activity as well as apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4897-4902
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• 2014

Purpose: To investigate the anticancer effects and underlying mechanisms of parthenolide on HepG2 human hepatocellular carcinoma cells. Materials and Methods: Cell viability was assessed by MTT assay and cell apoptosis through DAPI, TUNEL staining and Western blotting. Monodansylcadaverin(MDC) and AO staining were used to detect cell autophagy. Cell proliferation was assessed by Ki67 immunofluorescence staining. Results: Parthenolide induced growth inhibition in HepG2 cells. DAPI and TUNEL staining showed that parthenolide could increase the number of apoptotic nuclei, while reducing the expression of the anti-apoptotic protein Bcl-2 and elevating the expression of related proteins, like p53, Bax, cleaved caspase9 and cleaved caspase3. Parthenolide could induce autophagy in HepG2 cells and inhibited the expression of proliferation-related gene, Ki-67. Conclusions: Parthenolide can exert anti-cancer effects by inducing cell apoptosis, activating autophagy and inhibiting cell proliferation.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.413-417
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• 2015

Recently, we isolated HY253, a novel decahydrofluorene analog with a molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis, which is known as Dokwhal (獨活), a traditional medicinal herb. Moreover, we previously reported its cytotoxic activity on cancer cell proliferation in human lung cancer A549 and cervical cancer HeLa cells. The current study aimed to evaluate its detailed molecular mechanisms in cell cycle arrest and apoptotic induction in human hepatocellular carcinoma HepG2 cells. Flow cytometric analysis of HepG2 cells treated with $60{\mu}M$ HY253 revealed appreciable cell cycle arrest at the G1 phase via inhibition of Rb phosphorylation and down-regulation of cyclin D1. Furthermore, using western blots, we found that up-regulation of cyclin-dependent kinase inhibitors, such as p21^CIP1 and p27^KIP1, was associated with this G₁ phase arrest. Moreover, TUNEL assay and immunoblottings revealed apoptotic induction in HepG2 cells treated with $60{\mu}M$ HY253 for 24 h, which is associated with cytochrome c release from mitochondria, via down-regulation of anti-apoptotic Bcl-2 protein, which in turn resulted in activation of caspase-9 and -3, and proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, we suggest that HY253 may be a potent chemotherapeutic hit compound for treating human liver cancer cells via up-regulation and activation of the p53 gene.

• The Journal of Korean Medicine
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• v.29 no.4
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• pp.171-179
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• 2008

Objective: Bufonis Venenum is the traditional Korean medicine Chan Su, which is obtained from the skin and parotid venom gland of the toads. It has been used for myocardial diseases, inflammation diseases, pain relief, cancer and others. The main components of BV are cinobufotoxin, cinobufalin, bufalin and others. Of these, bufalin, the major active ingredient of BV, has been reported to induce apoptosis and to possess anti-tumor effects. There was no report of anti-tumor screening of BV on hepatic cancer and which signaling pathway can be involved. In order to examine the effect of BV on hepatic cancer and the related signaling pathway with BV-induced apoptosis, human Hep G2 cells were used. Methods: Analysis of apoptosis was confirmed by MTT assay. BV decreased cell viability in a dose and duration dependent manner. To observe which signaling molecules will be activated by BV, phosphorylation of MAPK (p38, ERK, JNK), caspase 8 and caspase 9 were examined by Western blot analysis. Results: The phosphorylation levels of p38 started to increase at 5 min after addition of 5 ${\mu}g$/ml of BV and sustained to increase until 48 hours. The phosphorylation levels of other MAPK (ERK and JNK), caspase 8 and caspase 9 increased in a time-dependent manner. These imply that BV may activate different signaling pathways, MAPK, caspase 8 and caspase 9. These results propose that BV may induce apoptosis on Hep G2 cells through the activation of MAPK, caspase 8 and caspase 9.