• The Korean Journal of Physiology and Pharmacology
• /
• 제19권2호
• /
• pp.119-124
• /
• 2015

The aim of the present study was to assess whether exposure to the combination of an extremely low frequency magnetic field (ELF-MF; 60 Hz, 1 mT or 2 mT) with a stress factor, such as ionizing radiation (IR) or $H_2O_2$, results in genomic instability in non-tumorigenic human lung epithelial L132 cells. To this end, the percentages of G2/M-arrested cells and aneuploid cells were examined. Exposure to 0.5 Gy IR or 0.05 mM $H_2O_2$ for 9 h resulted in the highest levels of aneuploidy; however, no cells were observed in the subG1 phase, which indicated the absence of apoptotic cell death. Exposure to an ELF-MF alone (1 mT or 2 mT) did not affect the percentages of G2/M-arrested cells, aneuploid cells, or the populations of cells in the subG1 phase. Moreover, when cells were exposed to a 1 mT or 2 mT ELF-MF in combination with IR (0.5 Gy) or $H_2O_2$ (0.05 mM), the ELF-MF did not further increase the percentages of G2/M-arrested cells or aneuploid cells. These results suggest that ELF-MFs alone do not induce either G2/M arrest or aneuploidy, even when administered in combination with different stressors.

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

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
• /
• pp.97-97
• /
• 2003

Embryonic stem (ES) cells, derived from preimplantation embryos, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES (hES, MB03) cells and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2 O_2$. Ratio of dying cells as determined by the relative amount of dye neutral red entrapped within the cells after the exposures. Cell death rates were not significantly different when either MB03 or HeLa were exposed up to 0.4 mM $H_2 O_2$. However, relative amount of dye entrapped within the cells sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2 O_2$, while it was approximately 54% in MB03. Pretreatment of cells with BSO (GSH chelator) and measurement of GSH content results suggest that cellular GSH is the major defensive mechanism of hES cells. Induction of apoptosis in hES cell was confirmed by DNA laddering, induction of Bax, and chromatin condensation. In summary, hES cells 1) are extremely resistant to oxidative stress, 2) utilize GSH as a major defensive mechanism. and 3) experience apoptosis upon exposure to oxidative stress.

• 한국약용작물학회지
• /
• 제13권5호
• /
• pp.219-226
• /
• 2005

Sanguisorbae radix (SR) from Sanguisorba officinalis L. (Losaceae) is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of SR on amyloid ${\beta}$ Protein(25-35) $(A{\beta}\;(25-35))$, a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. SR, over a concentration range of $10-50\;{\mu}g/ml$, inhibited the $A{\beta}$ (25-35) $(10\;{\mu}M)-induced$ neuronal cell death, as assessed by a 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. Pretreatment of SR $(50\;{\mu}g/ml)$ inhibited $10\;{\mu}M\;A{\beta}$ (25-35)-induced} elevation of cytosolic calcium concentration $([Ca^{2+}]c)$, which was measured by a fluorescent dye, fluo-4 AM. SR $(10\;and\;50\;{\mu}g/ml)$ inhibited glutamate release into medium induced by $10\;{\mu}M\;A{\beta}(25-35)$, which was measured by HPLC, and generation of reactive oxygen species. These results suggest that SR prevents $A{\beta}$ (25-35)-induced neuronal cell damage in vitro.

• 셀메드
• /
• 제2권3호
• /
• pp.26.1-26.5
• /
• 2012

Adverse side-effects and lack of scientific validation of some chemotherapeutic agents prevent the use of many traditional medicines claimed to have anti-cancer effects. Ethanolic extract of Conium maculatum has long been used in traditional and alternative systems of medicine including homeopathy for the treatment of glandular enlargements, cancerous tumours or hard lumps of testicles, prostate, ovaries, breasts and/ or uterus, particularly in the breast. However, if and how it acts still remains scientifically unknown. This study aims to test if Conium extract (CE), used as mother tincture of Conium in homeopathy, has demonstrable anti-cancer potentials without having much cytotoxicity in normal cells. Cytotoxicity of the drug was tested by conducting MTT assay on both normal (peripheral blood mononuclear cells) and HeLa cells. We also evaluated DNA fragmentation and DNA damage by DAPI and diphenylamine assay. The LDH activity assay was done to evaluate the percentages of apoptosis and necrosis. ROS accumulation also was evaluated to pin-point the actual events of apoptosis. Administration of drug clearly demonstrated its anti-cancer potentials as evidenced by the DNA damage analysis. The ROS activity also increased in case of the CE treated cells. LDH data revealed that the mode of cell death was mainly apoptotic and not necrotic. CE appears to induce apoptosis of cancer cells through ROS mediated pathway, and has negligible cytotoxicity against normal cells.

• 생명과학회지
• /
• 제26권5호
• /
• pp.614-619
• /
• 2016

Par-4는 다양한 세포사멸 자극에 세포 사멸을 조절하고, 종양 억제기능을 가지고 있다. 그러나, Par-4에 의한 암세포의 이동 및 침윤에 대한 연구는 수행되지 않았다. 본 연구에서 Par-4단백질의 과발현이 인간 신장암 Caki세포에서 MMP-2의 활성화를 억제하지만 MMP-9 활성에는 영향을 주지 않았다. Par-4에 의한 MMP-2의 활성 억제는 leucine zipper domain이 결실된 Par-4 에서는 확인되지 않았다. Par-4 siRNA를 이용한 knock-down 실험에서 PMA 처리 시 세포이동 및 침윤 증가함을 확인하였다. Par-4의 과발현과 knock-dwon에서 MMP-2 mRNA 발현의 변화를 확인 할 수 없었다. 이 점은 Par-4 매개의 MMP-2 활성 억제는 전사 후 조절을 통하여 야기됨을 추측 할 수 있다.

• Molecules and Cells
• /
• 제43권5호
• /
• pp.459-468
• /
• 2020

Nuclear receptor subfamily group H member 4 (NR1H4), also known as farnesoid X receptor, has been implicated in several cellular processes in the liver and intestine. Preclinical and clinical studies have suggested a role of NR1H4 in colon cancer development; however, how NR1H4 regulates colon cancer cell growth and survival remains unclear. We generated NR1H4 knockout (KO) colon cancer cells using clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (CAS9) technology and explored the effects of NR1H4 KO in colon cancer cell proliferation, survival, and apoptosis. Interestingly, NR1H4 KO cells showed impaired cell proliferation, reduced colony formation, and increased apoptotic cell death compared to control colon cancer cells. We identified MYC as an important mediator of the signaling pathway alterations induced by NR1H4 KO. NR1H4 silencing in colon cancer cells resulted in reduced MYC protein levels, while NR1H4 activation using an NR1H4 ligand, chenodeoxycholic acid, resulted in time- and dose-dependent MYC induction. Moreover, NR1H4 KO enhanced the anti-cancer effects of doxorubicin and cisplatin, supporting the role of MYC in the enhanced apoptosis observed in NR1H4 KO cells. Taken together, our findings suggest that modulating NR1H4 activity in colon cancer cells might be a promising alternative approach to treat cancer using MYC-targeting agents.

• 한국식품위생안전성학회지
• /
• 제28권3호
• /
• pp.202-206
• /
• 2013

악성도가 높은 점액표피양 암종은 치료가 어렵고 5년 생존률이 매우 낮다. 따라서, 새로운 치료 물질과 분자표적을 찾는 것이 필요하다. Betulinic acid (BA)는 세계적으로 쉽게 얻을 수 있는 물질인 동시에 여러 종류의 종양에서 항암효과를 보인다. 또한 여러 정상 조직은 BA에 저항성을 보인다. 이 연구에서는 BA의 증식억제 효능과 MC-3 세포주에서의 분자 표적을 확인하고자 하였다. BA는 MC-3 세포주에서 세포 생존을 저해하였고 세포사멸을 유도하였다. BA는 Sp 1과 그의 하향 분자 표적인 survivin에 영향을 주었으나, 다른 하향 분자 표적인 Mcl-1에서는 유의한 변화를 일으키지 못하였다. 따라서, BA는 Sp1과 survivin을 조절하여 세포사멸을 일으키는 잠재적인 항암제 후보가 될 수 있을 것이라 사료된다.

• 동의생리병리학회지
• /
• 제18권4호
• /
• pp.1120-1128
• /
• 2004

Zinc ion has both essential and toxic effects on mammalian cells. The results demonstrated that the ability of zinc to act as an inducer of apoptosis in C6 glial cells. Incubation with 0.2 mM ZnCl₂ caused cell death that was characterized as apoptosis by internucleosomal DNA fragmentation, formation of apoptotic bodies, nuclear fragmentation and breakdown of the mitochondrial membrane potential. ZnCl₂-induced apoptosis of C6 glial cells was prevented by the addition of Sibjeondaebo-Tang and antioxidants including reduced glutathione, N-acetyl-L-cysteine. We further confirmed that ZnCl₂ decreased the intracellular levels of GSH as well as generation of H₂O₂ in C6 glial cells. In 2D-electrophoresis, computer-assisted comparative analysis of the respective silver stained spot patterns revealed 3 groups with strongly decreased intensity by ZnCl₂. Whereas, 3 groups with increasing intensity were recovered by Sibjeondaebo-Tang. These results suggest that Sibjeondaebo-Tang may function as an antioxidant against free radicals and be applicable to the treatment of brain cells against oxidative stress.

• 동의생리병리학회지
• /
• 제18권5호
• /
• pp.1418-1425
• /
• 2004

The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.