• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.672-678
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• 2002

Oxidative stress contributes to cellular injury following clinical and experimental ischemia/reperfusion scenarios. Oxidative injury can induce cellular and nuclear damages that result in apoptotic cell death. We tested the hypothesis that the catechin flavonoid of (-)epigallocatechin gallate, a green tea polyphenol, inhibits hydrogen peroxide ($H_2O$$_2$)-induced apoptosis in human umbilical vein endothelial cells. The effect of apigenin, a flavone found in citrus fruits, on apoptosis parameters was also examined. A 30 min pulse treatment with 0.25 mM $H_2O$$_2$ decreased endothelial cell viability within 24 hrs by > 30% ; this was associated with nuclear condensation and biochemical DNA damage consistent with programmed cell death. In the 0.25 mM $H_2O$$_2$apoptosis model, 50${\mu}{\textrm}{m}$ (-)epigallocatechin gallate markedly increased cell viability with a reduction in the nuclear condensation and DNA fragmentation. In contrast, equimicromolar apigenin increased cell loss with intense DNA laddering, positive nick-end labeling and Hoechst 33258 staining. Thus, polyphenolic (-)epigallocatechin gallate, but not apigenin flavone, qualify as an antioxidant in apoptosis models caused by oxidative stress. Further work is necessary for elucidating the anti-apoptotic mechanisms of polyphenolic catechins.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.72-77
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• 2004

Previously, we synthesized a novel Cyclin-dependent kinase inhibitor, MCS-5A. Also, we investigated the involvement of cell cycle regulatory events during MCS-5A-mediated apoptosis in HL-60(+p16/-p53) cells with up-regulation of p16 protein expression. In contrast, apoptosis was not observed in A549(-p16/+p53) cells. Therefore we propose that $p16^{INK4A}$ is a key enzyme for inducing apoptosis. In the present studies, we have explored the mechanism of $p16^{INK4A}$ -mediated cytotoxicity and the role of p16.sup INK4A/ overexpression in the induction of apoptosis in human tumor cells. The tumor suppressor gene $p16^{INK4A}$ is known as a cyclin-dependent kinase inhibitor (CKI) and cell cycle regulator. We expressed wild type $p16^{INK4A}$ in pcDNA3.1 vector and then transfected into non-small cell lung cancer (NSCLC) cell expressing different statue of p16$^{INK4A}$, p53 gene〔A549(-p16/+p53), H1299(-p16/-p53) and HeLa(+pl6/+p53) cell line〕. TUNEL assay (including propidium iodide staining following transfection of these cell line with pcDNA3.1-pl6) indicate that p16$^{INK4A}$-mediated cytotoxicity was associated with apoptosis. This is supported by studies demonstrating an induction of caspase 3 cleavage due to the transfection of A549, H1299 and HeLa cells with pcDNA3.1-pl6. These results suggest that p16$^{INK4A}$ has a new function of inducing apoptosis which is not related with the function of tumor suppressor gene p53.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.107-113
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• 2007

목적 : 본 연구는 계혈등 약침액이 자궁경부암 세포주 SNU-17에서 세포 사멸 효과가 있는지 알아보고자 하였다. 방법 : 자궁경부암 세포주 SNU-17에서 세포 사멸의 변화를 관찰하기 위해서 MTT cytotoxicity assay, DAPI staining, TUNEL assay, RT-PCR analysis 방법을 이용하였다. 결과 : 세포독성 검사에서 계혈등 약침액은 자궁경부암 세포주 SNU-17에 농도 의존적으로 세포독성을 나타내었다. 이러한 계혈등 약침액의 세포독성이 세포사별로 인한 것인지 다른 기전에 의한 것인지 알아본 결과 계혈등 약침액에 의한 세포독성은 DAPI staining 과 TUNEL assay에서 세포사멸의 특정적인 소견들을 나타내었다. 계혈등 약침액이 Bax, Caspase-3의 발현에 미치는 영향을 RT-PCR로 관찰한 결과 계혈등 약침액은 Bax, Caspase-3의 발현을 증가시켰다. 결론 : 이상의 결과 계혈등 약침액이 자궁경부암 세포주 SNU-17에서 세포 사멸을 야기하여 자궁경부암의 치료에 유용할 것으로 사료된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1114-1119
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• 2008

Among the numerous polyphenols isolated from green tea, epigallocatechin gallate (EGCG) is a predominate and is considered to be a major therapeutic agent. To elucidate the mechanical insights of anti-tumor effect, EGCG was applied to human breast cancer MDA-MB-231 cells. We investigated the effect of EGCG on protein and mRNA expression of proteins related to cell apoptosis in MDA-MB-231 human breast cancer cell lines. We also identified caspase-3 activity. We cultured MDA-MB-231 cells in the presence of 0, 5, 10, and $20\;{\mu}M$ of EGCG. Protein and mRNA expression of bcl-2 were decreased dose-dependently in cells treated with EGCG. However, protein and mRNA expression of bax were increased (p<0.05). Caspase-3 activities were increased dose-dependently in cells treated with EGCG. These results suggest that EGCG induces cell apoptosis by increase of caspase activity through decreasing of protein and mRNA expression of bcl-2 and increasing of protein and mRNA expression of bax.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.739-747
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• 2014

The aim of the study was to determine the effects of Ixeris dentata extract (IDE) on anticancer activity in human breast cancer MDA-MB-231 cells at both cellular and molecular levels. The cells were cultured in the presence of 0, 20, 30 and $40{\mu}g/mL$ Ixeris dentata extract for 24 hours, respectively. At the end of culture, cytochemical analyses for MTT activity, trypan blue dye exclusion, Annexin V-FITC Apoptosis, and radical oxygen species (ROS) were conducted. RT-PCR was also performed to determine whether or not alterations in cell viability affect the Bax/Bcl-2 ratio. MTT assay showed that relative cell viability decreased in a dose-dependent manner (p<0.05). Reduction of cell viability matched well with increased cell membrane permeability as determined by trypan blue dye exclusion test (p<0.05). The rates of intracellular ROS also increased in a similar manner to those of TB-stained cells. There was an associated shift of apoptotic cells from early to late apoptosis between the 30 and $40{\mu}g/mL$. Bax/Bcl-2 ratio significantly increased along with significant decreases in Bcl-2 expression between 30 and $40{\mu}g/mL$ groups (p<0.05). In conclusion, anticancer activity of Ixeris dentata extract is modulated by a reduction in cell viability along with increased membrane permeability, leading to ROS accumulation within cells, and subsequently cell death through an apoptotic pathway that involves Bax and Bcl-2 in human breast cancer MDA-MB-231 cells.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.81-86
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• 2015

Intense pulsed light (IPL), a nonthermal technology, has attracted increasing interest as a food processing technology. However, its efficacy in inactivating microorganisms has not been evaluated thoroughly. In this study, we investigated the influence of IPL treatment on the inactivation of Escherichia coli O157:H7 depending on light intensity, treatment time, and pulse number. Increased light intensity from 500 V to 1,000 V, raised the inactivation rate at room temperature. At 1000 V, the cell numbers were reduced by 7.1 log cycles within 120 s. In addition, increased pulse number or decreased distance between the light source and sample surface also led to an increase in the inactivation rate. IPL exposure caused a significant increase in the absorption at 260 nm of the suspending agent used in our experiments. This indicates that IPL-treated cells were damaged, consequently releasing intracellular materials. The growth of IPL-irradiated cells were delayed by about 5 h. The degree of damage to the cells after IPL treatment was confimed by transmission electron microscopy.

• Development and Reproduction
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• v.8 no.1
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• pp.27-33
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• 2004

To investigate the mechanism of germ cell death in postnatal stage of mouse, the involvement of apoptotic executioners, caspase-3 and caspase-activated DNase(CAD), and apoptotic initiators, Bax Fas and Fas ligand, in the germ cell death has been studied. Immune-labels of active caspase-3 and CAD were located in TUNEL-positive, apoptotic, oocytes as well as normal oocytes of primary or secondary follicles. CAD immune-labels were also detected in the nucleus of TUNEL-positive oocytes. Most of oocytes showing positive immune-labeling of active caspase-3 or CAD had vacuoles in their cytoplasm, which is the morphological characteristic of oocyte during folliclar atresia. Bax immune-stains were detected in the atretic oocytes which showed the vacuole in their cytoplasm. Positive immune-labels for Fas ligand was localized in TUNEL-positive or atretic oocytes. Presence of immunoreactivity of active caspase-3 and CAD in TUNEL-positive germ cells implicate that active raspase-3 and CAD might play a role in germ cell apoptosis during early development of mouse ovarian follicle. Immunohistochemical localization of Bax and Fas ligand in TUNEL-positive oocytes suggests that these might be the most plausible modulator of oocyte apoptosis.

• Journal of Life Science
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• v.16 no.1
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• pp.30-36
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• 2006

Neutrophils are short-lived leukocytes that play a vital role in immune responses to bacteria, yeast, and fungi. This study was performed to investigate the effect of 4-O-methyl-ascochlorin (MAC), an anti-tumor, antibiotic, and anti-fungal prenyl-phenol compound on the spontaneous apoptosis of human neutrophils. MAC time- and dose-dependently accelerated the spontaneous apoptosis of human neutrophils. The effect of MAC on neutrophil apoptosis was blocked by pre-treatment of the neutrophils with specific inhibitors of pancaspase (zVAD-fmk), caspase-8 (zIETD-fmk), or caspase-3 (zDEVD-fmk). The cleavage of procaspase-8 and procaspase-3 was increased by MAC. Mitochondrial permeability, which was measured by the retention of $DiOC_6(3)$, was dose-de-pendently increased by MAC but the change of mitochondrial permeability was not blocked by pretreatment of neutrophils with zIETD-fmk. These results suggest that MAC induces neutrophil apoptosis by caspase-8-dependent but mitochondria-independent manner.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.1
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• pp.395-405
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• 2017

To confirm potential anti-cancer activities of ethylacetate (EtOAc) fraction from Orostachys japonicus on the A549 human lung cancer cells, this study examined. As a result of conducting MTS assay for measuring cell viability, the EtOAc fraction inhibited the proliferation of A549 cells in a dose-dependent manner. To investigate whether the inhibiting A549 cell viability was caused by apoptosis, this study analyzed chromatin condensation in A549 cells using DAPI staining. The morphological changes such as the formation of nuclear condensation were formed in a dose-dependent manner. Also, this study performed Annexin V-FITC staining for detecting phosphatidylinositol (PS). As a result of Annexin V-FITC staining to investigate level of early and late apoptosis, the apoptosis level treated with EtOAc fraction was higher than that of control. RT-PCR was performed to study the correlation between G2/M cell cycle arrest and cell cycle control genes. The anti-cancer activity of EtOAc fraction was accompanied by inhibition of CDK1, 4, cyclin B1 and D1 mRNA. This study also examined the expression of various marker proteins: p53, Bax, Bcl-2 and pro-caspase 3. Western blotting revealed that p53 and Bax proteins were up-regulated, and Bcl-2 and pro-caspase 3 proteins down-regulated in a time and dose-dependent manner.

• Journal of Life Science
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• v.22 no.5
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• pp.697-701
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• 2012

Activated protein C (APC) has an anticoagulant effect and a non-hemostatic effect such as regulation of cell metastasis and modulation of inflammation. In this study, we investigated whether APC could modulate apoptosis in cancer cells. Tumor necrosis factor (TNF)-${\alpha}$, cyclohexamide, and FAS markedly induced apoptosis in human renal carcinoma Caki cells. When Caki cells were pretreated with APC, the percentage of death receptor-induced apoptosis did not change. Furthermore, we checked the effect of APC on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in human glioma T98G and human breast carcinoma MDA231 cells. APC also had no effect on TRAIL-induced apoptosis in both cell lines. However, pretreatment with APC inhibited combination treatment (kahweol plus TRAIL and kahweol plus melatonin)-induced apoptosis and PARP cleavage in Caki cells. Taken together, our results suggest that APC can modulate anti-cancer therapeutic efficiency.