• Toxicological Research
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• 제23권3호
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• pp.215-221
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• 2007

Although sanguinarine, a benzophenanthridine alkaloid, possesses anti-cancer properties against several cancer cell lines, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. In order to further explore the critical events leading to apoptosis in sanguinarine-treated MCF-7 human breast carcinoma cells, the following effects of sanguinarine on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species (ROS), alteration of the mitochondrial membrane potential (MMP), and the expression changes of Bcl-2 family proteins. We show that sanguinarine-induced apoptosis is accompanied by the generation of intracellular ROS and disruption of MMP as well as an increase in pro-apoptotic Bax expression and a decrease of anti-apoptotic Bcl-2 and Bcl-xL expression. The quenching of ROS generation with N-acetyl-L-cysteine, the ROS scavenger, protected the sanguinarine-elicited ROS generation, mitochondrial dysfunction, modulation of Bcl-2 family proteins, and apoptosis. Based on these results, we propose that the cellular ROS generation plays a pivotal role in the initiation of sanguinarine-triggered apoptotic death.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.72-72
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• 2003

The PAS factor, whose gene has been cloned from V vulnifcus, is a protein secretion factor. Although the role of the PAS factor in Vibrio is still unknown, it may be involved with the bacterial protein secretion. The PAS factor is a 76 amino acid polypeptide, and its expression in E. coli cells makes the host cell membrane leaky, resulting in the excretion of periplasmic proteins into the culture medium. Highly expressed PAS factor is harmful to the cell, this may be due to a disruption of the membrane structure or function.

• 한국수산과학회지
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• 제50권4호
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• pp.388-395
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• 2017

We investigated the toxicity of zinc and aluminum hot-dip galvanized sheet steel to abalone Haliotis discus hannai via changes in the gill and hepatopancreas using histological and transmission electron microscopy analysis. Experimental groups were composed of one control and four exposure conditions (direct or indirect exposure to zinc and aluminum hot-dip galvanized sheet steel). In the control group, aluminum exposure groups (direct and indirect), and indirect zinc exposure group, abalone mortality was not observed until the end of the experiment, and no histopathological changes were observed in the gill and hepatopancreas. However, the direct zinc exposure group exhibited 100% mortality. Ultrastructural analysis of the cytoplasm of ciliated and microvilli-bearing epithelial cells from gill filaments revealed electron-dense vesicles near the cell membrane and disruption of the nuclear membrane. We also observed swollen mitochondria and a loss of mitochondrial cristae. The hepatopancreas showed similar changes, and we detected highly electron-dense particles within the vesicles. These results suggest that abalone exposed directly to zinc hot-dip galvanized sheet steel experience acute toxicity, causing damage to cell organelles in the gill and hepatopancreas and, finally, inducing mortality.

• 미생물학회지
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• 제24권3호
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• pp.270-275
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• 1986

Pseudomonas carboxydovorans와 Acinetobacter sp.l에 존재하는 일산화탄소 산화효소의 세포내 분포양상을 조사 하기 위 하여 엘 산 화탄소를 이 용하여 성장한 세균을 초음파로 파괴하거나 세균의 spheroplast을 만들어 삼투 충격으로 파괴한 후 soluble fraction과 particulate fraction에서의 일산화탄소 산화효소의 환성분포를 조사허여 비교하였다. 세균을 초음파로 파괴하였을 때는 crude cell extract에 존재하면 효소환성의 대부분이 soluble fracttion에서 검출되었다. 그러나 sphe roplas를 삼투충격으로 파괴하였을 때는 효소활성 이 세포막부분에서만 나타났다. 이와 같은 결과는 이 세균들의 일산화탄소 산화효소가 세포막에 느슨하게 붙이 있음을 시사하고 있다.

• 대한한의학회지
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• 제25권2호
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• pp.67-76
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• 2004

Objectives : This study was designed to investigate the protective mechanisms of Palmul-tang on hypoxia-induced cytotoxicity in H9c2 cardiomyoblast cells. Methods : In this study, we used H9c2 cells. Cells were subjected to hypoxia in the absence and presence of $1000\mu\textrm{g}/ml$ Palmul-tang for 24 hrs. Cells were treated with various concentrations of Palmul-tang for 24 hrs. Cell viability was measured by MTT assay. Hypoxia markedly decreased the viability of H9c2 cells, which was characterized with apparent apoptotic features such as chromatin condensation as well as fragmentation of genomic DNA and nuclei. Results : Palmul-tang significantly reduced hypoxia-induced cell death and apoptotic characteristics. Also, Palmul-tang prevented mitochondrial dysfunction including the disruption of mitochondrial membrane permeability transition (MPT) and an increase in expression of apoptogenic Bcl-2 proteins in hypoxia-H9c2 cells. Conclusions; This study suggests that the protective effects of Palmul-tang against hypoxic damages may be mediated by the modulation of Bcl-2, Bax expression.

• The Korean Journal of Physiology and Pharmacology
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• 제24권6호
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• pp.529-543
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• 2020

In contrast to ventricular myocytes, the structural and functional importance of atrial transverse tubules (T-tubules) is not fully understood. Therefore, we investigated the ultrastructure of T-tubules of living rat atrial myocytes in comparison with ventricular myocytes. Nanoscale cell surface imaging by scanning ion conductance microscopy (SICM) was accompanied by confocal imaging of intracellular T-tubule network, and the effect of removal of T-tubules on atrial excitation-contraction coupling (EC-coupling) was observed. By SICM imaging, we classified atrial cell surface into 4 subtypes. About 38% of atrial myocytes had smooth cell surface with no clear T-tubule openings and intracellular T-tubules (smooth-type). In 33% of cells, we found a novel membrane nanostructure running in the direction of cell length and named it 'longitudinal fissures' (LFs-type). Interestingly, T-tubule openings were often found inside the LFs. About 17% of atrial cells resembled ventricular myocytes, but they had smaller T-tubule openings and a lower Z-groove ratio than the ventricle (ventricular-type). The remaining 12% of cells showed a mixed structure of each subtype (mixed-type). The LFs-, ventricular-, and mixed-type had an appreciable amount of reticular form of intracellular T-tubules. Formamide-induced detubulation effectively removed atrial T-tubules, which was confirmed by both confocal images and decreased cell capacitance. However, the LFs remained intact after detubulation. Detubulation reduced action potential duration and L-type Ca²⁺ channel (LTCC) density, and prolonged relaxation time of the myocytes. Taken together, we observed heterogeneity of rat atrial T-tubules and membranous ultrastructure, and the alteration of atrial EC-coupling by disruption of T-tubules.

• Journal of the Korean Wood Science and Technology
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• 제50권1호
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• pp.12-30
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• 2022

Many studies on plant extracts have been reported for the treatment of candidiasis caused by Candida albicans, a representative fungal infection. This study demonstrates the synergistic antifungal activity of the combination of Phellodendri Cortex and Magnoliae Cortex, previously reported to have antifungal efficacy. Considering the antifungal efficacy and the separation of the active constituents, berberine and magnolol, hot water extraction and carbon dioxide supercritical extraction were selected for Phellodendri Cortex and Magnoliae Cortex, respectively. A combination of 0.55 g/L hot water extract of Phellodendri Cortex and 0.59 g/L carbon dioxide supercritical extract of Magnoliae Cortex showed synergistic antifungal activity. The synergistic antifungal activity of 160 μM berberine and 100 μM magnolol, which are representative antifungal compounds of Phellodendri Cortex and Magnoliae Cortex, respectively, contributes to the synergistic antifungal effect of their extracts. The additive decrease in cellular ergosterol level and the increased antifungal efficacy by extracellular ergosterol suggest that disruption of the biological function of ergosterol in the cell membrane is not responsible for the synergistic antifungal activity of berberine and magnolol. Synergistic cellular release of chromosomal DNA upon mixing berberine and magnolol indicates that disruption of the cellular structure is responsible for the synergistic antifungal effect of berberine and magnolol.

• 대한한의학회지
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• 제24권2호
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• pp.159-165
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• 2003

Objectives : Coptidis rhizoma (CR) is an oriental medicine that has been used in many traditional prescriptions against diabetes mellitus in Korea for centuries. Our purpose was to determine the protective effect and its action mechanism of CR on the cytotoxicity of pancreatic -cell line (RINm5F cell). Methods : In this experiment, we used methods such as MTT assay for detection of cytotoxicity, DNA fragmentation assay for detection of apoptotic cell death, LDH activity assay for detection of necrotic cell death, and measurement of $DiOC_{6}$ (3) retention for detection of mitochondrial membrane potential (MMP). Background : Nitric oxide (NO) is believed to playa key role in the process of pancreatic -cell destruction leading to insulin-dependent diabetes mellitus (IDDM). Results : Exposure of RINm5F cells to chemical NO donor such as S-nitroso-N-acetylpenicillamine (SNAP) induced cytotoxic events such as DNA fragmentation and lactate dehydrogenase (LDH) release into medium. However, pretreatment of RINm5F cells with CR extract ($10~50{\mu\textrm{g}}/ml$) for 3 hours prevented SNAP-induced DNA fragmentation and LDH release into medium through the inhibition of MMP disruption. Conclusions : These results suggest that CR may be a candidate for a therapeutic or preventing agent against IDDM.

• 생명과학회지
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• 제26권12호
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• pp.1458-1465
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• 2016

본 연구는 oxidative stress에 의한 세포죽음 분석의 이상적인 모델로 사용되는 HT22세포를 이용하여 천문동 에탄올추출물의 glutamate에 의한 oxidative toxicity에 대한 신경보호 효과를 살펴보았다. 이를 위해 cell viability, lactate dehydrogenase (LDH), 그리고 세포죽음형태, reactive oxygen species (ROS), mitochondria membrane potential (MMP) 등에 대한 flow cytometry 및 Western blot분석을 이용하였다. 천문동 추출물의 처리는 cell viability 및 LDH분석에서 glutamate에 의한 cell toxicity를 저하시키며, 특히 apoptotic cell death를 현저히 감소시켰다. ROS 및 MMP분석 결과, 천문동 추출물은 ROS의 형성을 저하시키며 glutamate에 의해 저하된 MMP를 현저히 회복시켜 주었다. 이와 관련된 단백질 발현을 보면, 천문동 추출물은 PARP 및 HO-1의 발현을 억제하였다. 이상의 결과는 천문동 추출물이 HT22해마세포에서 ROS형성저해 및 MMP회복에 의해 세포죽음을 완화시켜 보호작용을 하는 것으로 사료되며 oxidative toxicity관련 질환에 적용 가능할 것으로 보여 진다.

• 대한한의학방제학회지
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• 제26권3호
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• pp.251-259
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• 2018

Objective : Kurarinone is one of the flavonoids isolated from Sophorae Radix with various biological activities including anti-microbial effect. In this study, we investigated the effects of Kurarinone on tert-butyl hydroperoxide (tBHP)-induced oxidative stress finally leading to apoptosis in human hepatoma cell line HepG2. Methods : To determine the effects on cell viability, the cells were exposed to tBHP ($100{\mu}mol/l$) after pretreatment with kurarinone (0.5 and $1{\mu}g/ml$). Cell viability was measured by MTT assay. To reveal the possible mechanism of cytoprotectivity of kurarinone, levels of reactive oxygen species, intracellular glutathione, mitochondrial membrane potential, and expression of caspase were examined. Results : tBHP-induced cell death was due to oxidative stress and the resulting apoptosis. Kurarinone dose-dependently protected cells from apoptosis when determined by MTT and TUNEL assay. Consistent with this observation, decreased expression of pro-caspase 3/9 protein by tBHP was restored by kurarinone. Kurarinone also showed anti-oxidative effects by inhibiting generation of ROS and depletion of GSH in tBHP-stimulated HepG2 cells. In addition, kurarinone significantly recovered disruption of mitochondrial membrane potential (MMP) as a start sign of hepatic apoptosis induced by oxidative stress. Conclusion : From these results, it was concluded that kurarinone protected tBHP-induced hepatotoxicity with anti-oxidative and anti-apoptotic activities. Our results suggest that kurarinone might be beneficial to hepatic disorders caused by oxidative stress.