• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.505-509
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• 2002

In the course of screening program for VHR DS-PTPase (dual-specificity protein tyrosine phosphatase) from natural sources, Gastrodia elata was selected. One compound showing potent inhibitory activity was isolated by the solvent extraction and column chromatography including silica gel, ODS RP-18, Sephades LH-20, and HPLC. This compound was identified as baicalein by several NMR techniques such as $^1H-NMR$, $^{13}C-NMR$, and DEPT. Baicalein showed selective inhibitory activity against VHR DS-PTPase with $IC_{50}=2.4\;{\mu}M$, and showed cytotoxicity against several human cancer cell lines with an $GI_{50}$ of $5.26{\sim}12.93\;{\mu}g/mL$ range, including, melanoma (LOX-IMVI), lung cancer (NCI H23 and A549), colon cancer (HCT 116 and SW 620), prostate cancer (PC-3), and leukemia (MOLT 4F).

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.130.2-130.2
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• 2010

한전 전력연구원에서는 2009년 12월부터 125 kW급 용융탄산염 연료전지 발전시스템의 성능평가를 위한 운전이 진행되고 있다. 현재 진행 중인 "250 kW급 열병합 용융탄산염 연료전지 Proto Type개발" 과제의 최종시작품인 250 kW급 발전시스템은 125 kW급 MCFC 스택 2기로 설계되어, 125 kW급 시스템의 시험운전은 매우 중요한 기술적 성과가 될 것이다. 현재 125 kW급 MCFC 스택은 10,000 $cm^2$의 유효전극면적을 갖는 단위전지들로 구성되었으며, 적층 스택의 온도 및 농도분포의 최적화를 위해 내부 매니폴드 및 Co-flow Type 열교환기 기반의 분리판을 개발 적용하였다. 연료극의 전극 구성은 Ni-Al alloy로, 공기극의 전극 구성은 Lithiated-NiO로 이루어졌다. 그리고 매트릭스는 ${\alpha}-LiAlO_2$로 제작되었고, 전해질은 Li과 K Carbonate가 68 : 32 비율로 섞인 용융염을 사용하였다. 본 125 kW급 용융탄산염 연료전지 시스템의 운전평가는 고적층 스택의 온도 및 농도 분포를 확인하고, 최적화된 스택 운전 조건을 도출하는 것을 그 목적으로 하고 있다. 125kW급 스택 1기의 규모의 주변기기 시스템은 외부개질기, 촉매연소기, 이젝터, 고온순환 블로어 및 공기블로어 등으로 이루어져 있다. 고온형 연료전지 시스템에서 연료극과 공기극의 균일한 온도 및 압력 확보는 매우 중요하며, 이를 위하여 외부개질기 및 촉매연소기 연동을 통한 온도편차를 최소화하고, 기존 고온용 순환 블로어 대신 이젝터를 개발 도입하여 압력균형을 조절하였다. 125kW급 MCFC 시스템은 2009년 12월부터 전처리 운전을 시작하여 2010년 1월 말부터 PCS로 전기를 생산하고 있다. 평균전압 0.83V에서 100kW의 출력을 기록하였으며, 피크부하 120 kW, 누적출력량 30 MWh를 초과달성하였다.

• Journal of Life Science
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• v.26 no.3
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• pp.359-363
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• 2016

We have screened four natural products against 640 single compounds, which shows more two folds gene expression for both endoplasmic reticulum aminopeptidase 1 (ERAP1) and FOXO-family transcription factor (FOXO1). The results were as follows. (±)-Car-3-ene-2,5-dione from Asarum sieboldii Miq. is C₁₀H₁₂O₂ molecular formula and the 164 kDa molecular weight. Cinobufagin from Bufonis Venennum is C₂₆H₃₄O₆ molecular formula and 442 kDa molecular weight. So far reported main biological function is Na⁺/K⁺-ATPase inhibition. Corilagin from Euphorbia pekinensis is C₂₇H₂₂O₁₈ molecular formula and 634 kDa molecular weight. Carbonic anhydrase inhibition is well known its biological function. Corydaline from Corydalis turtschaninovii is C₂₂H₂₇NO₄ molecular formula and 369 kDa molecular weight. The main biological function is acetylcholinesterase inhibition. In the short future, four types of natural products will be used in longevity experiments with insects. The results may give one of the clues for studying new drug development candidates of the longevity.

• Toxicological Research
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• v.20 no.3
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• pp.241-250
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• 2004

We previously found that bisphenol A (BPA) caused neurotoxic behavioral alteration. Since disturbance of calcium homeostasis is an implicated contributor in the neurotoxic mechanism of environmental toxicants, we investigated whether BPA alters calcium homeostasis. Unlike other neurotoxic agents which cause increase of intracellular calcium level, BPA decreased $[Ca^{2+}]_i$ dose-dependently in PC12 cells and cortical neuronal cells regardless of the calcium existence in buffer. BPA at greater concentrations than 100 $\mu\textrm{M}$ reduced cell viability significantly in both types of cells. BPA also suppressed L-glutamate (L-type channel activator, 30 mM) and trifluoperazine (calmodulin antagonist, 30 $\mu\textrm{M}$)-induced increase of $[Ca^{2+}]_i$. BPA further lowered caffeine (RYR activator, 100 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$, but did not alter dantrolene (RYR inhibitor, 100 $\mu\textrm{M}$), heparin (IP3 inhibitor, 200 units/ml) and xestospongin C (IP3 inhibitor, 5 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$. Cell viability was not directly related to intracellular calcium change by bisphenol A that alternation of intracellular calcium may not be a direct causal factor of BPA-induced neuronal cell death.

• Archives of Pharmacal Research
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• v.28 no.9
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• pp.1073-1078
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• 2005

A presenilin 2 mutation is believed to be involved in the development of Alzheimer's disease. In addition, transgenic mice with a presenilin 2 mutation have been reported to have learning and memory impairments. In this study, exposing PC12 cells expressing mutant presenilin 2 to $50{\mu}M\;A{\beta}_{25-35},\;30mM$ L-glutamate and $50{\mu}M\;H_2O_2$ caused a significant increase in acetylcholine esterase activity. An in vivo study revealed high levels of this enzyme activity in the mutant presenilin 2 transgenic brains compared with the wild type presenilin 2 transgenic and non-transgenic samples. These results suggest that a mutant presenilin 2-induced neurodegeneration in Alzheimer's disease might be involved in the increase in acetylcholinesterase activity. These findings might help in the development of an appropriate therapeutic intervention targeting mutant presenilin 2-induced Alzheimer's disease.

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.128-136
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• 2004

CYP1A1 is known to be inducible by xenobiotic compouds such as polyciclic aromatic hydrocarbons(PAHs) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). These chemicals have been identified worldwide and can have a significant impact on the human health and well being of human and wildlife. Given these issues, the detection and quantification of these chemicals in biological, environmental and food samples is important. First, we investigated the effect of on CYP1A1 promoter activity, 7-ethoxyresorufin-O-deethylase(EROD) activity and CYP1A1 mRNA expression induced by benzo(k)fluoranthene(B(k)F) in MCF-7 cells. We found that B(k)F significantly up-regulates the level of CYP1A1 prompter activity, EROD and CYP1A1 mRNA. When cells were treated with genistein, it was not changed that EROD and CYP1A1 mRNA, compared to that of control. However, genistein inhibited the B(k)F-induced CYP1A1 promoter activity and mRNA level at high concentration. Furthermore, in this study, effects of HDAC(histone deacetvlase) inhibitors on human prostate cancer cells proliferation were examined. HC-toxin, SAHA and TSA inhibited cell proliferation in PC3 cells. A novel HDAC inhibitor, IN2001 also suppressed the growth of PC3 cells. And IN2001 and SAHA increased S phase and G2/M phase at 12 hrs treatment but cells were arrested G0/G1 phase at 45 hrs treatment. The HC-toxin treatment for 24 hrs and 48 hrs increased G0/G1 at low concentration ($0.1\mu\textrm{m}$) but increased G2/M at more than concentration of $1\mu\textrm{m}$. TSA increased G2/M phase. These findings height the possbility of developing HDAC inhibitors as potential anticancer therapeutic agents for the treatment of prostate cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.765-768
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• 2013

Background and Aims: Prostate cancer is the most commonly diagnosed cancer in males in many populations. Metformin is the most widely used anti-diabetic drug in the world, and there is increasing evidence of a potential efficacy of this agent as an anti-cancer drug. Metformin inhibits the proliferation of a range of cancer cells including prostate, colon, breast, ovarian, and glioma lines. MicroRNAs (miRNAs) are a class of small, non-coding, single-stranded RNAs that downregulate gene expression. We aimed to evaluate the effects of metformin treatment on changes in miRNA expression in PC-3 cells, and possible associations with biological behaviour. Materials and Methods: Average cell viability and cytotoxic effects of metformin were investigated at 24 hour intervals for three days using the xCELLigence system. The $IC_{50}$ dose of metformin in the PC-3 cells was found to be 5 mM. RNA samples were used for analysis using custom multi-species microarrays containing 1209 probes covering 1221 human mature microRNAs present in miRBase 16.0 database. Results: Among the human miRNAs investigated by the arrays, 10 miRNAs were up-regulated and 12 miRNAs were down-regulated in the metformin-treated group as compared to the control group. In conclusion, expression changes in miRNAs of miR-146a, miR-100, miR-425, miR-193a-3p and, miR-106b in metformin-treated cells may be important. This study may emphasize a new role of metformin on the regulation of miRNAs in prostate cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.938-947
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• 2016

Antioxidant activities and neuroprotective effects of ethyl acetate fraction from Dendropanax morbifera (EFDM) against high glucose-induced oxidative stress and neurotoxicity were investigated to confirm their physiological activities. An 80% ethanolic extract of D. morbifera showed the highest contents of total phenolic compounds as well as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. The extract was fractionated using several solvents, and the ethyl acetate fraction showed the highest activities in ferric reducing/antioxidant power and malondialdehyde inhibitory assays. To evaluate the neuroprotective effect based on antioxidant activities, cell viability was assessed using PC12 and MC-IXC cells in $H_2O_2$- and high glucose-induced cytotoxic assays, respectively. EFDM evidently showed neuroprotective effects in all cells (neuron-like PC12 cells and human brain-originated neuroblastoma MC-IXC cells). Inhibitory effect of the extract on acetylcholinesterase (AChE) as an acetylcholine-hydrolyzing enzyme was performed to examine the effect on cognitive function. EFDM presented an AChE inhibitory effect. Finally, high-performance liquid chromatography analysis showed that the major phenolic compound of EFDM is probably a rutin.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.220-225
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• 2002

To determine the anti-stress effect of KCG(加味天麻鉤藤飮) extract on sprague-dawley rats. we conducted a research about the change of weight, activity, reactivity, c-fos protein, cytotoxicity against PC12 cell line and heal shock protein. 1) KCG extract siginificantly inhibited the decrease of body weight induced by stress, compared with the control group. 2) KCG extract had no siginificant effect in the activity and reactivity of rats between the control and the experimental groups. 3) KCG extract siginificantly restrained c-fos protein manifestation, compared with the control group. 4) KCG extract siginificantly restrained heat shock protein, compared with the control group. These results suggested that KCG might be usefully anti-stress effect.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3150-3158
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• 1997

In the ATM networks, there are two method in traffic control as schemes to improve the quality of service; one is the reactive control after congestion and the other is the preventive control before congestion. The preventive control include the CAC(Connection Admission Control), the UPC(Usage Parameter Control), the NPC(Network Parameter Control) and the PC(Priority co ntrol). In this paper, we propose an efficient UPC algorithm that has a complex structure using the Jumping window algorithm within the Leaky Bucket algorithm. The proposed algorithm controls peak hit rate by the Leaky Bucket algorithm, then it does the traffic control to evaluate by the Jumping Window whether violates mean bit rate or not. As we assume On/Off traffic source model, our simulation results showed cell loss rate less than the pre-existential Leaky Bucket algorithm method, and it could decrease the demanded Bucket size.