• Tuberculosis and Respiratory Diseases
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• 제72권4호
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• pp.343-351
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• 2012

Background: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit this pathway are currently under development for lung cancer treatment. In the present study, we have tested whether dual inhibition of PI3K/Akt/mTOR signaling can lead to enahnced antitumor effects. We have also examined the role of autophagy during this process. Methods: We analyzed the combination effect of the mTOR inhibitor, temsirolimus, and the Akt inhibitor, GSK690693, on the survival of NCI-H460 and A549 non-small cell lung cancer cells. Cell proliferation was determined by MTT assay and apoptosis induction was evaluated by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Autophagy induction was also evaluated by acridine orange staining. Changes of apoptosis or autophagy-related proteins were evaluated by western blot analysis. Results: Combination treatment with temsirolimus and GSK690693 caused synergistically increased cell death in NCI-H460 and A549 cells. This was attributable to increased induction of apoptosis. Caspase 3 activation and poly(ADP-ribose) polymerase cleavage accompanied these findings. Autophagy also increased and inhibition of autophagy resulted in increased cell death, suggesting its cytoprotective role during this process. Conclusion: Taken together, our results suggest that the combination of temsirolimus and GSK690693 could be a novel strategy for lung cancer therapy. Inhibition of autophagy could also be a promising method of enhancing the combination effect of these drugs.

• 대한본초학회지
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• 제26권3호
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• pp.47-56
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• 2011

Objectives : This study investigated whether the water extract of Spatholobi Caulis (SCE) has the ability to protect hepatocyte against oxidative stress induced by tert-butylhydroperoxide (tBHP) in vitro and $CCl_4$ in vivo. Methods : In vitro, HepG2 cells pre-treated with Spatholobi Caulis water extract (1, 3, 10, $30{\mu}g$/ml) for 12h and further incubated with tBHP ($100{\mu}M$) for the next 12h. Cell viability was assessed by MTT assay. In vivo, rats were orally administrated with the aqueous extract of Spatholobi Caulis (SCE; 50, 100 mg/kg) for 4 days and then, injected with $CCl_4$ 1 mg/kg body weight to induce acute liver damage. Results : Treatment with SCE inhibited cell death induced by tBHP, as evidenced by alterations in the levels of the proteins associated with apoptosis:SCE prevented a decrease in $Bcl_2$, and cleavage of poly(ADP-ribose)polymerase and pro-caspase-3. Moreover, SCE inhibited the ability of tBHP to generate $H_2O_2$ production, thereby restoring GSH content. Moreover, SCE treatments in rats effectively decreased liver injuries induced by a single dose of $CCl_4$, as evidenced by decreases in hepatic degeneration and inflammation as well as plasma alanine aminotransferase and lactate dehydrogenase activities. Consistently, treatments of SCE also protected liver in rats stimulated by $CCl_4$, as indicated by restoration GSH and prevention of MDA in the liver. Conclusions : SCE has the ability 1) to protect hepatocyte against oxidative stress induced by tBHP and 2) to prevent $CCl_4$-inducible acute liver toxicity. Present findings may be informative not only in elucidating the pharmacological mechanism of Spatholobi Caulis, but in determining its potential application for oxidative cellular damage in the liver.

• 한방비만학회지
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• 제15권2호
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• pp.93-103
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• 2015

Objectives: It was investigated the cytoprotective efficacies of isorhamnetin, a flavonoid originally derived from Hippophae rhamnoides L., against oxidative stress-induced apoptosis in C2C12 myoblasts. Methods: The effects of isorhamnetin on cell growth, apoptosis and reactive oxygen species (ROS) generation were evaluated by trypan blue dye exclusion assay, 4',6-diamidino-2-phenylindole staining and flow cytometry. The levels of apoptosis-regulatory and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins, and caspase activities (caspase-3 and -9) were determined by Western blot analysis and colorimetric assay, respectively. Results: Our results revealed that treatment with isorhamnetin prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the C2C12 cell viability and, indicating that the exposure of C2C12 cells to isorhamnetin conferred a protective effect against oxidative stress. Isorhamnetin also effectively attenuated $H_2O_2$-induced apoptosis and ROS generation, which was associated with the restoration of the upregulation of Bax and downregulation of Bcl-2 induced by $H_2O_2$. In addition, $H_2O_2$ enhanced the activation of caspase-9 and -3, and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3; however, these events were almost totally reversed by pretreatment with isorhamnetin. Moreover, isorhamnetin increased the levels of heme oxygenase-1, a potent antioxidant enzyme, associated with the induction of Nrf2. Conclusions: Our data indicated that isorhamnetin may potentially serve as an agent for the treatment and prevention of muscle disorders caused by oxidative stress.

• 한국자원식물학회지
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• 제28권3호
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• pp.297-304
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• 2015

The flower buds of Sophora japonica L (SF), as a well-known traditional Chinese medicinal herb, have been used to treat bleeding-related disorders such as hematochezia, hemorrhoidal bleeding, dysfunctional uterine bleeding, and diarrhea. However, no specific anti-cancer effect and its molecular mechanism of SF have been described. Thus, we performed in vitro study to investigate if treatment of SF affects activating transcription factor 3 (ATF3) expression and ATF3-mediated apoptosis in human colorectal cancer cells. The effects of SF on cell viability and apoptosis were measured by MTT assay and Western blot analysis against cleaved poly (ADP-ribose) polymerase (PARP). ATF3 activation induced by SF was evaluated using Western blot analysis, RT-PCR and ATF3 promoter assay. SF treatment caused decrease of cell viability and increase of apoptosis in a dose-dependent manner in HCT116 and SW480 cells. Exposure of SF activated the levels of ATF3 protein and mRNA via transcriptional regulation in HCT116 and SW480 cells. Inhibition of extracellular signal-regulated kinases (ERK) 1/2 by PD98059 and p38 by SB203580 attenuated SF-induced ATF3 expression and transcriptional activation. Ectopic ATF3 overexpression accelerated SF-induced cleavage of PARP. These findings suggest that SF-mediated apoptosis may be the result of ATF3 expression through ERK1/2 and p38-mediated transcriptional activation.

• 대한한방부인과학회지
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• 제19권1호
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• pp.69-80
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• 2006

Purpose : This study is to evaluate the synergistic cytotoxicity of Rhizoma Rehmanniae(RR), in adriamycin-treated HeLa human cervical carcinoma cells. Methods : We culture HeLa cell which is human metrocarcinoma cell in D-MEM included 10% fetal bovine serum(Hyclone Laboratories) below $37^{\circ}C$, 5% $CO_2$. Then we observed apoptosis of log phage cell which is changed cultivation liquid 24 Hours periodically. Results : The combination of RR and adriamycin synergistically augmented the cytotoxicity of HeLa cells. The apoptotic cell death was accompanied by the activation of caspase-3 and -8 as well as cleavage of poly(ADP- ribose) polymerase (PARP) in HeLa cells. The co-treatment of RR with adriamycin didn't have any effect on either the expression of Bcl-2 or that of Bax. Interestingly, a synergistic increase in apoptosis by the combination of two drugs was accompanied by the enhancement of Pas and Fas ligand (FasL) expression in HeLa cells. Taken together, the combination of RR and adriamycin significantly augmented the apoptotic cytotoxicity of Fas-positive cells, such as HeLa cells. The pathway is not involved in mitochondria-dependent pathway. Conclusion : RR induces apoptosis in HeLa cells via p38 MAPK activation.

• Molecules and Cells
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• 제43권7호
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• pp.632-644
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• 2020

The molecular mechanism underlying autophagy impairment in the retinal pigment epithelium (RPE) in dry age-related macular degeneration (AMD) is not yet clear. Based on the causative role of poly(ADP-ribose) polymerase 1 (PARP1) in RPE necrosis, this study examined whether PARP1 is involved in the autophagy impairment observed during dry AMD pathogenesis. We found that autophagy was downregulated following H₂O₂-induced PARP1 activation in ARPE-19 cells and olaparib, PARP1 inhibitor, preserved the autophagy process upon H₂O₂ exposure in ARPE-19 cells. These findings imply that PARP1 participates in the autophagy impairment upon oxidative stress in ARPE-19 cells. Furthermore, PARP1 inhibited autolysosome formation but did not affect autophagosome formation in H₂O₂-exposed ARPE-19 cells, demonstrating that PARP1 is responsible for impairment of late-stage autophagy in particular. Because PARP1 consumes NAD⁺ while exerting its catalytic activity, we investigated whether PARP1 impedes autophagy mediated by sirtuin1 (SIRT1), which uses NAD⁺ as its cofactor. A NAD⁺ precursor restored autophagy and protected mitochondria in ARPE-19 cells by preserving SIRT1 activity upon H₂O₂. Moreover, olaparib failed to restore autophagy in SIRT1-depleted ARPE-19 cells, indicating that PARP1 inhibits autophagy through SIRT1 inhibition. Next, we further examined whether PARP1-induced autophagy impairment occurs in the retinas of dry AMD model mice. Histological analyses revealed that olaparib treatment protected mouse retinas against sodium iodate (SI) insult, but not in retinas cotreated with SI and wortmannin, an autophagy inhibitor. Collectively, our data demonstrate that PARP1-dependent inhibition of SIRT1 activity impedes autophagic survival of RPE cells, leading to retinal degeneration during dry AMD pathogenesis.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• Journal of Applied Biological Chemistry
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• 제63권3호
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• pp.283-290
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• 2020

Oxidative stress is one of the contributors of neurodegenerative disorders including Alzheimer's disease. According to previous studies, Aster yomena (Kitam.) Honda (AY) possesses variable pharmacological activities including anti-coagulant and anti-obesity effect. In this study, we aimed to determine the neuroprotective effect of ethyl acetate fraction from Aster yomena (Kitam.) Honda (EFAY) against oxidative stress. Therefore, we carried out 3-(4,5-dimethylthiazol-2-yl)-2,3-diphenyl tetrazolium bromide, lactate dehydrogenase (LDH), and 2',7'-dichlorofluorescin diacetate assays in SH-SY5Y neuronal cells treated with hydrogen peroxide (H₂O₂). H₂O₂-treated control cells exhibited reduced viability of cells, and increased LDH release and reactive oxygen species (ROS) production compared to normal cells. However, treatment with EFAY restored the cell viability and inhibited LDH release and ROS production. To investigate the underlying mechanisms by which EFAY attenuated neuronal oxidative damage, we measured protein expressions using Western blot analysis. Consequently, it was observed that EFAY down-regulated cyclooxygenase-2 and interleukin-1β protein expressions in H₂O₂-treated SH-SY5Y cells that mediated inflammatory reaction. In addition, apoptosis-related proteins including B-cell lymphoma-2-associated X protein/B-cell lymphoma-2 ratio, cleaved caspase-9, and cleaved-poly (ADP-ribose) polymerase protein expressions were suppressed when H₂O₂-treated cells were exposed to EFAY. Our results indicate that EFAY ameliorated H₂O₂-induced neuronal damage by regulating inflammation and apoptosis. Altogether, AY could be potential therapeutic agent for neurodegenerative diseases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.68-68
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• 2018

In this study, we investigated whether S. baicalensis rhizome ethanol extract (SBRE) has antioxidant capacities against oxidative stress induced cellular damage in the HaCaT keratinocytes. Our results revealed that treatment with SBRE prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the HaCaT cell viability. SBRE also effectively attenuated $H_2O_2$ induced comet tail formation, and inhibited the $H_2O_2$ induced phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V positive cells. In addition, SBRE exhibited scavenging activity against intracellular ROS generation and restored the mitochondria membrane potential loss induced by $H_2O_2$. Moreover, $H_2O_2$ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with SBRE. Furthermore, SBRE increased the levels of HO-1 associated with the induction of Nrf2. Therefore, we believed that SBRE may potentially serve as an agent for the treatment and prevention of neurodegenerative diseases caused by oxidative stress.

• 한국환경성돌연변이발암원학회지
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• 제20권1호
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• pp.14-20
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• 2000

DHAQ-97, (2-(3-[p-bis(2-chloroethyl)aminophenyl]-2 formylaminopropanoyloxy) methy1-1,4-dihy-droxy-9,10-anthraquinone), is a novel anthraquinone derivative synthesized for use as an anti-neoplastic agent. In the present study, we have evaluated the selective cytotoxicity of DHAQ-97 by comparing its effects on viability and proliferation of human breast cancer cell line (NCF-7) versus normal immortalized breast epithelial cell line (MCF-10A). Thus, DHAQ-97 reduced both viability and proliferation of MCF-7 cells to a much greater extent than did for MCF-10A cells. The growth inhibitory and anti-proliferative properties of DHAQ-97 appear to be attributable to its ability to induce apoptosis as revealed by positive staining after in 냐셔 nick-end labeling (TUNEL), cleavage of poly(ADP-ribose)polymerase, release of mitochondrial cytochrome c into cytoplasm, and increased expression of pro-apoptotic Bax protein. Recent studies have indicated possible involvement of the ubiquitous eukaryotic transcription factor, NF-kappa B (NF-kB) in the regulation of apoptotic cell death. In line induced cytotoxicity in cultured MCF-7 cells. Furthermore, mild activation of NF-kB, as determined by its increased DNA binding capability, was observed 30 min after treatment with 10$\mu\textrm{m}$ DHAQ-97. Taken together, the above findings suggest that DHAQ-97 exerts selective cytotoxicity towards cancer cells through induction of apoptosis, which appears to be regulated by NF-kB.