• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.119-122
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• 2002

Oryza sativa cv. Mihyangbyo is one of several recently developed varieties of rice; characterized by high levels of aromatic components, which may increase its sensory and nutritional properties. In conjunction with our continuing investigation of bioactive components of improved grain varieties, a quinolone alkaloid was isolated from the n-butanol soluble fraction of the aleurone layer of Oryza sativa cv. Mihyangbyo (Gramineae) through activity-guided fractionation and isolation. The compound exhibited moderate antineoplastic activity in a human leukemia cell line (U937) with an $IC_{50}$/ value of 118.1 ug/mL, based on the MTT(3-[4, 5]dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) cell proliferation assay. The chemical structure of the functional compound was determined, based on physical and spectroscopic characteristics.

• Radiation Oncology Journal
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• 제19권2호
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• pp.163-170
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• 2001

목적 : 방사선조사후 세포의 생존 분획은 세포집락 측정기법으로 확인하는 것이 표준이나 많은 비용과 시간이 소요되는 단점을 갖고 있다. 이에 생존 세포의 tetrazolium염의 자색 formazan 침전물로의 환원시키는 능력에 그 기반을 둔 MTT 기법을 사용하여 세포집락 측정기법을 대체하기 위한 기법으로서의 유용성과 그 실행상의 최적조건을 규명하고자 하였다. 방법 : PCI-1, SNU-1066, NCI-H630, RKO등의 세포주에 0, 2, 4, 6, 8, 10 Gy의 방사선을 조사한 후 세포집락 측정 기법과 MTT기법으로 세포 생존 분획을 조사하였다. 세포집락 측정기법은 $25\;cm^2$ 폴리스티렌 배양 플라스크에 방사선량에 따라 다른 수의 세포를 분주한 후 24시간 동안 배양 후 방사선을 조사하였고 이를 $10\~14$일 동안 배양 후 염색하여 생성된 세포집락의 수를 측정하였다. MTT기법은 침전물의 용해과정이 필요없는 Premix WST-1 시약을 이용하여 시행하였다. MTT기법은 각각의 세포주에서 세포수와 흡광도간의 선형관계와 최적 실험조건을 확인한 이후 시행하였다. 이 기법은 방사선을 조사받은 세포에서는 지수적 성장을 회복한 이후와 방사선을 조사받지 않은 세포는 4회 이상의 세포분열을 거친 후에 시행하였다. 세포집락 측정기법 및 MTT기법을 통하여 얻은 세포 생존율을 구한 후 이를 지표로 비교하였다. 결과 : 각 기법으로 얻은 세포 생존율의 표준편차는 $5\%$ 내외였다. 2가지 방법으로 구한 세포 생존율은 t-test로 비교하였을 때 $0\~4\;Gy$에서는 통계적으로 유의한 차이가 없었으며 회귀분석 결과는 선형적 관계가 있었다$(R^2=0.975-0.992)$. MTT 기법의 시행에 최적인 세포수는 배양효율에 따라 다른 것으로 나타났는데, 배양효율이 $30\%$ 이상이면 300개 이하가, $30\%$ 미만인 경우는 $500\~1,000$개가 적당한 것으로 확인되었다. MTT기법은 6 배가시간 경과 이후에 시행하는 것이 세포집락 측정기법과 가장 근접하였으며 적어도 4 배가시간 이후에 시행하는 것이 필요할 것으로 사료되었다. 이에 따르면 배가시간이 3일 이하인 세포주가 세포 민감성 측정방법으로서 MTT 기법이 세포 집락 측정 기법을 대체하여 사용하기에 적합한 것으로 사료되었다. 결론 : 이상에서, MTT기법을 이용하여 방사선조사 후의 세포생존을 측정하기 위해서는 예비실험을 통해 각 세포주에서의 최적의 조건을 찾는 것이 필수적이며 이 조건하에서 MTT기법을 시행해야만 방사선에 의한 세포 민감성 측정에 이용될 수 있음을 확인하였다.

• 약학회지
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• 제21권3호
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• pp.167-171
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• 1977

A new assay method for delta-l-dehydrogenated-3-ketoco-rticosteroid in the presence of proteinous material or whole-cell-enzyme and 3-ketocorticosteroid has been developed. This method makes use of the linear relationship between the ratio of absorbances at 265 nm and at 242 nm and the fractional concentration of delta-1-3-ketosteroid. Theoretical values were calculated based on the absorbances of proteinous material at fixed concentrations of the 3-ketosteroid and delta-1-dehydrogenated-3-ketosteroid. The values obtained experimentally showed good agreement with the values obtained experimentally showed good agreement with the values theoretically predicted. The new assay method developed for the steroid mixtiure containing proteinous material is of some practical importance. The use of such assay method enables one to determine the enzyme activity and the rate of enzyme reaction or conversion rather quickly, easily and accurately. By the use of this assay method, the reaction kinetics of whole-cell-enzyme has also been studied. It was found that it followed the simple Michaelis-Menten type enzyme kinetics. Also the reversibility of this reaction with actively metabolizing cell was examined. It was found that delta-l-dehydrogenated-3-ketosteroid could not be hydrogenated reversibly to 3-ketosteroid by this enzyme system.

• Toxicological Research
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• 제23권2호
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• pp.143-150
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• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1933-1938
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• 2014

Despite increasing importance of in vitro cell-based assays for the assessment of nanoparticles (NPs) cytotoxicity, their suitability for the assessment of NPs toxicity is still in doubt. Here, limitations of widely used cell viability assay protocol (i.e., MTT asssay) for the cytotoxicity assessment of P25 $TiO_2$ NPs were carefully examined and an alternative toxicity assessment method to overcome these limitations was proposed, where the artifacts caused by extracellularly formed formazan and light scattered by agglomerated NPs were minimized by measuring only the intracellular formazan via image cytometric methods.

• Radiation Oncology Journal
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• 제26권3호
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• pp.166-172
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• 2008

목 적: 암환자의 방사선 치료 전 방사선에 대한 감수성을 미리 측정할 수 있다면 임상적으로 많은 도움이 될 것이다. 본 연구는 전 임상 실험을 통하여 MTT assay가 세포집락 측정기법과 비교해서 방사선 감수성을 예측할 수 있고, 직장암 환자의 조직에 사용할 수 있는지 가능성을 확인하고자 하였다. 대상 및 방법: 대장암 세포 주인 HCT-8, LoVo, CT-26, WiDr을 이용하여 세포집락 측정기법을 통해 세포생존곡선 및 2 Gy에서의 세포생존확률(SF2)을 구하였다. 세포 주 자체를 대상으로 MTT assay를 시행하는 실험(in vitro) 및 환자의 암 조직과 같은 상태를 만들기 위하여, 누드 마우스에 세포 주를 주입하여 암 조직을 형성한 후 in vitro와 같은 방식으로 MTT assay를 시행(ex vivo)하였다. 이 두 실험에 대한 흡광도 값에 따른 저해율(inhibition rate, %)을 구하였다. 결 과: $SF_2$ 및 세포생존곡선에 따르면 CT-26 및 LoVo가 HCT-8, WiDr에 비해 방사선에 민감하였다(p<0.05). In vitro MTT assay 결과 WiDr, HCT-8, LoVo와 CT-26의 방사선 저해율이 각각 17.3%, 21%, 30%, 56.5%를 나타내었다. 또한 ex vivo MTT assay의 저해율은 HCT-8, WiDr, LoVo와 CT-26에서 각각 23.5%, 26%, 38%, 53%를 나타내었다. 통계적인 차이를 감안하였을 때 세포생존곡선을 통해 얻은 방사선 감수성의 결과와 동일한 순서를 가졌다. 결 론: 4개의 세포 주의 방사선의 감수성의 순서가 세포집락 측정기법 및 in vitro와 ex vivo MTT assay 결과에서 거의 일치함을 보였다. 이는 직장암 환자에서 MTT assay를 통해 방사선 감수성을 예측할 수 있는 가능성을 제시하였다.

• Toxicological Research
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• 제19권1호
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• pp.45-50
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• 2003

The purpose of this study was to determine the role of substituted groups in phenolic compounds to develop an anticancer agent having strong cytotoxicity against cancer cells but weak against normal cells. The phenolic compounds used in this study were gallic acid and ferulic acid with hydroxyl and carboxyl groups, syringic acid with hydroxyl, carboxyl and methoxy groups, and pyre-gallol with hydroxyl groups. Cytotoxicities of these compounds were evaluated by MTT assay for cell viability and XTT assay for cell adhesion activity in normal human skin fibroblast (Detroit 551) and human skin melanoma (SK-MEL-3) cells. Syringic acid, gallic acid and ferulic acid decreased the cell viability and cell adhesion activity in SK-MEL-3 cells but not in Detroit 551 cells while pyrogallol decreased in both cells. The susceptibility of cell viability based on the $IC_{50}$ values of MTT assay in Detroit 551 cells was in the following order: pyrogallol > gallic acid > ferulic acid > syringic acid, while it was in SK-MEL-3 cells: Syringic acid > progallol > ferulic acid > gallic acid. These results suggest that carboxyl and methoxy groups of these compounds play an important role in selectivity of cytotoxicity in normal and cancer cells.

• Biomolecules & Therapeutics
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• 제19권1호
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• pp.134-139
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• 2011

Sphingosine kinase (SPHK) has a central role to control cell death and cell proliferation, which is suggested as a sphingolipid rheostat by regulating the levels between ceramide and sphingosine 1-phosphate (S1P). Therefore, physiological regulators of SPHK will be a good candidate to develop a new targeted drug. For this purpose, a series of synthetic pseudoceramides were tested by SPHK assay either cell-based or cell-free system. K10PC-5 strongly inhibited SPHK, while K6PC-5 activated SPHK in cell-free system. Specifically, K6PC-5 activated SPHK under the co-treatment with $50\;{\mu}M$ dimethylsphingosine (DMS), a SPHK inhibitor. Collectively, we developed a simple SPHK assay system to find SPHK regulatory pseudoceramide compounds, K10PC-5 and K6PC-5 which may be useful to cancer treatment or immune regulation like FTY720, a synthetic sphingolipid mimetic compound.

• 대한화장품학회지
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• 제15권1호
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• pp.37-50
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• 1989

The in Vitro chemosensitivity of fibroblast cell strains was determined using a semiautomated tetrazolium-based colorimetric assay(MTT assay) to 16 cosmetic materials. This assay is useful method to evaluate toxic effects of the chemicals. From assay results, we determined that the preservatives are more toxic than moisteurizers. The chemicals in the same group have a different toxicity. That is, in preservatives, Germall -115 is more toxic than Danisol -M, -p, and in surfactant sodium laurel sulfate than Myrj 52, and in moisteurizers, 1, 3-butylene glycol is more safe than the others. When the results from this assay for preservatives were compared with patch test results, good correlation was observed. Forthemore, this assay method can be used together with Patch test for the evaluation of the chemical toxicity, particularly in cosmetic field.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.62-62
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• 2019

Natural substances have various physiological activities. Substances isolated from natural substances are known to be safer and more potent than pharmaceuticals. Potatoes not only act as energy sources but also contain active ingredients such as vitamins and minerals. In particular, the potato contains a large amount of polar compounds, including the saponin in the polar compounds, and the physiological activity of the saponins, such as immunity enhancement, antioxidant and anti-inflammatory is known. In this study, the antioxidative activity of polar compounds from five potatoes was examined by chemical base anti-oxidation assay and cell based anti-oxidation assay. In the chemical base anti-oxidation assay, DPPH experiment showed activity in the order of Hongyoung, Haryung, Seohong, Sumi, and Jayoung. In the LPA experiment, IC50 was lower in the order of Jayoung, Seohong, Sumi, Hongyoung, and Haryung. In the cell based anti-oxidation assay, the smallest amount of ROS was generated when the compound was derived from Haryung and hongyoung, and strong SOD activity was observed in Sumi and Jayoung. The results of this study reveal the antioxidative effect of polar compounds extracted from various kind of potatoes, which will enable the acquisition of new bioactive candidates and the establishment of new profit generation models for farmers.