• Journal of Life Science
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• v.21 no.11
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• pp.1549-1557
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• 2011

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in many types of transformed cells; however, some human hepatocellular carcinoma cells are particularly resistant to the effects of TRAIL. Although genistein, a natural isoflavonoid phytoestrogen, has been shown to have pro-apoptotic activity against human cancer cell lines, little is known about the mechanism of genistein in terms of TRAIL-induced apoptosis. In the present study, it was investigated whether or not combined treatment with genistein and TRAIL synergistically induced apoptosis in Hep3B hepatocarcinoma cells. Results indicate that treatment with TRAIL in combination with nontoxic concentrations of genistein sensitized TRAIL-resistant Hep3B cells to TRAIL-induced apoptosis, which was associated with mitochondrial dysfunction. Further, the inhibition of p38 mitogen-activated protein kinase (MAPK) activation markedly decreased genistein and TRAIL-induced cell viability and apoptosis by enhanced truncation of Bid, increase of pro-apoptotic Bax, decrease of anti-apoptotic Bcl-2, and release of cytochrome c from mitochondria to cytoplasm. Activation of caspases and degradation of poly (ADP-ribose) polymerase induced by the combined treatment was also markedly increased by the inhibition of p38 MAPK, through the mitochondrial amplification step. In conclusion, our data suggest that genistein sensitizes TRAIL-induced-apoptosis via p38 MAPK-dependent pathway.

• Journal of Life Science
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• v.23 no.1
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• pp.143-156
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• 2013

Due to the high incidence of cancer and cancer-related mortality in Korea, there is increased concern and psychological anxiety about this disease, leading to increasing numbers of cancer studies. Despite these, the trend of the cancer incidence rate has shown a significant increase. The detection of colorectal cancer, which has a high incidence rate, often tends to be delayed, causing a high mortality rate. Therefore, the prevention of colorectal cancer has become an important emergent issue. The cause of this cancer has not been confirmed. However, it may be attributable to westernized dietary patterns, which include consuming a high quantity of red meat. Consumption of dietary fiber promotes the production of butyrate short-chain fatty acids by enteric bacteria. In the treatment of cancer, anticancer medications have been shown to lead to the apoptosis of tumor cells, and a strong relationship between apoptosis mechanisms of tumor cells and cancer treatment has been confirmed. The results of many studies have confirmed that butyrate can directly promote the apoptosis of colorectal cancer cells. Therefore, increased consumption of dietary fiber, which promotes the production of butyrate shortchain fatty acids, can be expected to have an effect on the prevention and treatment of colorectal cancer.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1325-1335
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• 2018

Objective: This study investigated whether spermine supplementation could regulate cell cycle, apoptosis, and amino acid transporter-related genes expression in the thymus and spleen of early weaned piglets. Methods: Eighty female piglets were randomly distributed to receive adequate nutrients supplemented with spermine (0.4 mmol/kg body weight/24 h) or to be provided with restricted nourishment supplemented with normal saline for 7 h or 3, 6, or 9 d in pairs. Results: Regardless of administration time, spermine supplementation significantly up-regulated cyclin A2 gene expression but down-regulated p21 and cyclin D3 mRNA levels in the thymus and spleen and reduced cyclin E2 gene expression in the thymus of piglets (p<0.05). Irrespective of the treatment period, the reduced Bax and caspase-3 gene expressions and improved Bcl-2 mRNA level were observed in the thymus and spleen of spermine-administrated piglets (p<0.05). Regardless of supplementation time, spermine intake significantly enhanced the expressions of amino acid transporter-related genes (SLC1A1, SLC1A5, SLC7A1, SLC7A7, and SLC15A1) in both thymus and spleen, as well as SLC7A9 in the spleen of piglets (p<0.05). In addition, extended spermine administration also markedly promoted cell proliferation, depressed apoptosis and modulated amino acid transport (p<0.05), and such effects were the greatest during prolonged spermine supplementation (6 d) compared to the other time periods (p<0.05). Conclusion: Spermine supplementation may regulate cell cycle during the G1/S phase, suppress apoptosis and modulate amino acid transport. A period of 6 d of spermine supplementation is required to produce the optimal effects on nutritional implications.

• Journal of Ginseng Research
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• v.44 no.4
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• pp.664-671
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• 2020

Background: Ginsenoside compound-Mc1 (Mc1) is a member of the deglycosylated ginsenosides obtained from ginseng extract. Although several ginsenosides have a cardioprotective effect, this has not been demonstrated in ginsenoside Mc1. Methods: We treated H9c2 cells with hydrogen peroxide (H₂O₂) and ginsenoside Mc1 to evaluate the antioxidant effects of Mc1. The levels of antioxidant molecules, catalase, and superoxide dismutase 2 (SOD2) were measured, and cell viability was determined using the Bcl2-associated X protein (Bax):B-cell lymphoma-extra large ratio, a cytotoxicity assay, and flow cytometry. We generated mice with high-fat diet (HFD)-induced obesity using ginsenoside Mc1 and assessed their heart tissues to evaluate the antioxidant effect and the fibrosis-reducing capability of ginsenoside Mc1. Results: Ginsenoside Mc1 significantly increased the level of phosphorylated AMP-activated protein kinase (AMPK) in the H9c2 cells. The expression levels of catalase and SOD2 increased significantly after treatment with ginsenoside Mc1, resulting in a decrease in the production of H₂O₂-mediated reactive oxygen species. Treatment with ginsenoside Mc1 also significantly reduced the H₂O₂-mediated elevation of the Bax:Bcl2 ratio and the number of DNA-damaged cells, which was significantly attenuated by treatment with an AMPK inhibitor. Consistent with the in vitro data, ginsenoside Mc1 upregulated the levels of catalase and SOD2 and decreased the Bax:B-cell lymphoma-extra large ratio and caspase-3 activity in the heart tissues of HFD-induced obese mice, resulting in reduced collagen deposition. Conclusion: Ginsenoside Mc1 decreases oxidative stress and increases cell viability in H9c2 cells and the heart tissue isolated from HFD-fed mice via an AMPK-dependent mechanism, suggesting its potential as a novel therapeutic agent for oxidative stress-related cardiac diseases.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.246-253
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• 2010

Ginsenoside $Rg_3$ ($Rg_3$), one of the active ingredients in Panax ginseng, attenuates NMDA receptor-mediated currents in vitro and antagonizes NMDA receptors through a glycine modulatory site in rat cultured hippocampal neurons. In the present study, we examined the neuroprotective effects of $Rg_3$ on 24-hydroxycholesterol (24-OH-chol)-induced cytotoxicity in vitro. The results showed that $Rg_3$ treatment significantly and dose-dependently inhibited 24-OH-chol-induced cell death in rat cultured cortical neurons, with an $IC_{50}$ value of $28.7{\pm}7.5\;{\mu}m$. Furthermore, the $Rg_3$ treatment not only significantly reduced DNA damage, but also dose-dependently attenuated 24-OH-chol-induced caspase-3 activity. To study the mechanisms underlying the in vitro neuroprotective effects of $Rg_3$ against 25-OH-chol-induced cytotoxicity, we also examined the effect of $Rg_3$ on intracellular $Ca^{2+}$ elevations in cultured neurons and found that $Rg_3$ treatment dose-dependently inhibited increases in intracellular $Ca^{2+}$, with an $IC_{50}$ value of $40.37{\pm}12.88\;{\mu}m$. Additionally, $Rg_3$ treatment dose-dependently inhibited apoptosis with an $IC_{50}$ of $47.3{\pm}14.2\;{\mu}m$. Finally, after confirming the protective effect of $Rg_3$ using a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, we found that $Rg_3$ is an active component in ginseng-mediated neuroprotection. These results collectively indicate that $Rg_3$-induced neuroprotection against 24-OH-chol in rat cortical neurons might be achieved via inhibition of a 24-OH-chol-mediated $Ca^{2+}$ channel. This is the first report to employ cortical neurons to study the neuroprotective effects of $Rg_3$ against 24-OH-chol. In conclusion, $Rg_3$ was effective for protecting cells against 24-OH-chol-induced cytotoxicity in rat cortical neurons. This protective ability makes $Rg_3$ a promising agent in pathologies implicating neurodegeneration such as apoptosis or neuronal cell death.

• Journal of Acupuncture Research
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• v.31 no.1
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• pp.111-119
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• 2014

Objectives : I investigated whether Bee Venom can synergistically strengthen the cytotoxic effects of NK-92 cells, enhancing the inhibition of the growth of Lung Cancer Cells including A549 and NCI-H460 through induction of death receptor dependent extrinsic apoptosis and NO generation in the Nitro-oxide pathway. Methods : Bee Venom inhibited cell proliferation of A549 or NCI-H460 Human Lung Cancer Cells as well as NK-92 Cells. Moreover, when they were co-punctured with NK cells and concomitantly treated by 3 ${\mu}g/ml$ of Bee Venom, more influence was exerted on inhibition of proliferation of A549 or NCI-H460 Human Lung Cancer Cells than BV or NK cell co-culture alone. Results : The expression of Fas, TNFR2, DR3, DR6 in A549 Lung Cancer Cells was significantly increased by co-culture of NK-92 cells and treatment of 3 ${\mu}g/ml$ of Bee Venom, compared to co-culture of NK-92 cells alone, whereas the expression of Fas, TNFR2, DR6 in NCI-H460 Lung Cancer Cells was significantly increased by co-culture of NK-92 cells, representing no synergistic effects in the co-culture of NK-92 cell and concomitant treatment of 3 ${\mu}g/ml$ of Bee Venom. Coincidently, caspase-8, a expression of pro-apoptotic proteins in the extrinsic apoptosis pathway demonstrated same results as the above. Meanwhile, In NO generation, there is little change of NO generation in co-culture of NK-92 cells with A549 cells as well as the co-culture of NK-92 cell with them and concomitant treatment of 3 ${\mu}g/ml$ of Bee Venom, whereas increase of NO generation was shown in co-culture of NK-92 cells with NCI-H460 cells as well as the co-culture of NK-92 cell with them and concomitant treatment of 3 ${\mu}g/ml$ of Bee Venom, although synergistic effects by Bee Venom was not found. Conclusions : These present data provide that Bee Venom could be useful candidate compounds to enhance lung cancer growth inhibiting ability of NK-92 cells through DR expression and the related apoptosis.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.97-105
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• 2014

The aim of this study was to determine the beneficial effect of propofol on human keratinocytes that have undergone hypoxia reoxygenation (H/R) injury and to investigate whether autophagy is associated with the protective mechanism. Thus, we evaluated how propofol influences the intracellular autophagy and apoptosis during the H/R process in the HaCaT cells. The cultured human keratinocyte cells were exposed to 24 h of hypoxia (5% $CO_2$, 1% $O_2$, 94% $N_2$) followed by 12 h of reoxygenation (5% $CO_2$, 21% $O_2$, 74% $N_2$). The experiment was divided into 4 groups: (1) Control=Normoxia ; (2) H/R=Hypoxia Reoxygenation ; (3) PPC+H/R=Propofol Preconditioning+Hypoxia Reoxygenation; (4) 3-MA+PPC+ H/R=3-MA-Methyladenine+Propofol Preconditioning+ Hypoxia Reoxygenation. In addition, Western blot analysis was performed to identify the expression of apoptotic pathway parameters, including Bcl-2, Bax, and caspase 3 involved in mitochondrial-dependent pathway. Autophagy was determined by fluorescence microscopy, MDC staining, AO staining, and western blot. The H/R produced dramatic injuries in keratinocyte cells. In our study, the viability of Propofol in H/R induced HaCaT cells was first studied by MTT assay. The treatment with 25, 50, and $100{\mu}M$ Propofol in H/R induced HaCaT cells enhanced cell viability in a dose-dependent manner and $100{\mu}M$ was the most effective dose. The Atg5, Becline-1, LC3-II, and p62 were elevated in PPC group cells, but H/R-induced group showed significant reduction in HaCaT cells. The Atg5 were increased when autophagy was induced by Propofol, and they were decreased when autophagy was suppressed by 3-MA. These data provided evidence that propofol preconditioning induced autophagy and reduced apoptotic cell death in an H/R model of HaCaT cells, which was in agreement with autophagy playing a very important role in cell protection.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.392-402
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• 2017

Background: Previously, we reported that Korean Red Ginseng inhibited liver fibrosis in mice and reduced the expressions of fibrogenic genes in hepatic stellate cells (HSCs). The present study was undertaken to identify the major ginsenoside responsible for reducing the numbers of HSCs and the underlying mechanism involved. Methods: Using LX-2 cells (a human immortalized HSC line) and primary activated HSCs, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assays were conducted to examine the cytotoxic effects of ginsenosides. $H_2O_2$ productions, glutathione contents, lactate dehydrogenase activities, mitochondrial membrane permeabilities, apoptotic cell subpopulations, caspase-3/-7 activities, transferase dUTP nick end labeling (TUNEL) staining, and immunoblot analysis were performed to elucidate the molecular mechanism responsible for ginsenoside-mediated cytotoxicity. Involvement of the AMP-activated protein kinase (AMPK)-related signaling pathway was examined using a chemical inhibitor and small interfering RNA (siRNA) transfection. Results and conclusion: Of the 11 ginsenosides tested, 20S-protopanaxadiol (PPD) showed the most potent cytotoxic activity in both LX-2 cells and primary activated HSCs. Oxidative stress-mediated apoptosis induced by 20S-PPD was blocked by N-acetyl-$\text\tiny L$-cysteine pretreatment. In addition, 20S-PPD concentration-dependently increased the phosphorylation of AMPK, and compound C prevented 20S-PPD-induced cytotoxicity and mitochondrial dysfunction. Moreover, 20S-PPD increased the phosphorylation of liver kinase B1 (LKB1), an upstream kinase of AMPK. Likewise, transfection of LX-2 cells with LKB1 siRNA reduced the cytotoxic effect of 20S-PPD. Thus, 20S-PPD appears to induce HSC apoptosis by activating LKB1-AMPK and to be a therapeutic candidate for the prevention or treatment of liver fibrosis.

• Journal of Life Science
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• v.21 no.1
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• pp.89-95
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• 2011

p53 is tumor suppressor gene that regulates apoptosis such as caspase-dependent and p21-mediated signaling pathways. PI3K/Akt is known to be over-activated in cancer cells. Akt activates many survival-related signals such as mTOR and COX-2. Inactivation of Akt would result in non-inhibition of p53 as well as induced apoptosis. In this study, we showed that curcumin and EGCG activate p53 via inhibition of the Akt signaling pathway. Treatments using curcumin and EGCG in different concentrations for 24 hr and 48 hr inhibited proliferation of HCT116 colon cancer cells and increased apoptotic cell death. Also, our data showed that curcumin and EGCG increased the p53 expression and decreased the p-Akt. Treatment of LY294002 (Akt inhibitor) resulted in decreased cell proliferation of cancer cells, while LY294002 treated with curcumin or EGCG showed a greater decrease of cell proliferation. In addition, inhibition of Akt induced p53 activation in HCT116 colon cancer cells. These results suggest that curcumin and EGCG induce apoptosis by inhibiting Akt and increase p53 in HCT116 colon cancer cells.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1665-1672
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• 2012

An 80% ethanol extract of Hizikia fusiforme was obtained and followed by successive fractionation using the organic solvents n-hexane, ethyl acetate, and n-butanol to identify the antioxidative substance. The aqueous part of the nbutanol fractionation step, showing high antioxidative activity, was subjected to reverse-phase liquid chromatography. As a result, a substance purified from a BB-2 fraction showed high antioxidative activity. The m/z 419 [M+H] molecular ion peak in the fraction was observed by the analysis of the ESI-LC/MS spectrum. By the analysis of 1H NMR (500 MHz, DMSO-$d_6$) and $^{13}C$ NMR (125 MHz, DMSO-$d_6$) spectra, a unique compound of the fraction was biochemically identified as a 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5HHMF). We also investigated the effect of 5HHMF on human gastric AGS carcinoma cells. Western blot analysis suggested that the flavone substantially increased the levels of the death receptor-associated apoptosis mediators Fas, Fas L, FADD, TRADD, and DR4 in a concentration-dependent manner. The levels of Fas, Fas L, TRADD, and DR4 in the cells treated with 5HHMF ($5{\mu}g/ml$) were approximately 26.4-, 12.8-, 6.7-, and 9.8-times higher than those of non-treated cells, respectively. Of note, the level of FADD protein in the cells exposed to 5HHMF ($1{\mu}g/ml$) increased approximately 9.6-times. In addition, the cleavage of caspase-3, -8, and -9 in cultured AGS cells treated with 5HHMF was significantly confirmed. Therefore, our results suggest that 5HHMF from H. fusiforme is involved in the induction of death receptor-associated apoptosis mediators in human gastric AGS carcinoma cells.