• Title/Summary/Keyword: synergistic effect

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Anti-proliferative Effect of Tetra-arsenic Oxide (TetraAs®) in Human Gastric Cancer Cells in Vitro

  • Chung, Won-Heui;Koo, Hye-Jin;Kuh, Hyo-Jeong
    • Journal of Pharmaceutical Investigation
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    • v.37 no.5
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    • pp.305-309
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    • 2007
  • Arsenic compounds have been used to treat various diseases including cancer in oriental medicine. Arsenic trioxide ($As_2O_3,\;Trisenox^{(R)}$) has been used for the treatment of leukemia and its anti-solid tumor activity has also been reported recently. Tetra-arsenic oxide ($As_4O_6,\;TetraAs^{(R)}$) is a newly developed arsenic compound which has shown an anticancer activity in some human cancer cell lines. The purpose of this study was to evaluate the anti-gastric cancer potential of TetraAs and to search for an agent with synergistic interaction with TetraAs against human gastric cancers. We analysed anti-proliferative effect of TetraAs when given alone and in combination with other chemotherapeutic agents such as 5-FU, paclitaxel, and cisplatin in SNU-216, a human gastric cancer cell line. The $IC_{50}$ of these 4 anti-cancer drugs ranged from 5.8 nM to $7.5\;{\mu}M$ with a potency rank of order paclitaxel>TetraAs>cisplatin>5-FU. TetraAs showed 10-fold greater potency than 5-FU and cisplatin at the same effect level of $IC_{50}$. TetraAs+5-FU and TetraAs+paclitaxel showed synergistic and additive interaction, respectively. On the other hand, TetraAs with cisplatin group appeared to be strongly antagonistic. Apoptotic population was measured and compared between single and combination treatment. The apoptotic cells for the combination of TetraAs+5-FU showed significant increase compared to single TetraAs treatment. On the contrary, TetraAs+cisplatin showed less apoptotic cells compared to TetraAs or cisplatin alone treatment. Overall, our results indicate that TetraAs can be effectively combined with 5-FU or paclitaxel, but not with cisplatin for synergistic anti-cancer effect, which warrants further evaluation using in vivo models.

Exploring synergistic effect among essential oils in antibacterial action (항균작용에 대한 에센셜 오일들 간의 상승작용 탐색)

  • Kim, Ka-Eun;Park, Soon Kwon;Cho, Il-Young
    • Journal of Digital Convergence
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    • v.14 no.8
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    • pp.547-553
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    • 2016
  • This study was conducted to look at the antimicrobial synergistic effect of blended oil into the target skin flora. The essential oils used in antimicrobial test were 100% eucalyptus (EU), lemon (LE), lavender (LA) and four blended oils, EU+LE, LE+LA, EU+LA, and, EU+LE+LA in ratio of 1:1 and 1:1:1 respectively. As a result, LE showed the highest, LA showed the lowest antimicrobial activity among single oil group. In blended oil group, antimicrobial activity of the EU + LA showed significantly increasing effect than the sum of the antimicrobial activity of the single oil. However, the antimicrobial effects of the blend of three oils did not show any synergistic effect. This result showed that the interaction between the chemical components constituting the oil than the number of blended oil seems more significant on the synergistic effect. Therefore, blending essential oil based on scientific evidence becomes more necessary in the future.

Effects of Growth Factors and Gut Regulatory Peptides on Glucose Uptake in HC 11 Mouse Mammary Epithelial Cells

  • Myung, K.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.11
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    • pp.1690-1694
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    • 2003
  • The large and rapid changes of glucose utilization in lactating mammary tissue in response to changes in nutritional state must be largely related by external signal of insulin. This also must be related with the quantity and composition of the diet in vivo. To characterize the mode of growth factors and gut regulatory peptides with insulin, in vitro experiment was conducted with HC11 cells. All the growth factor alone and the combinations of growth factors significantly (p<0.05) increased in glucose uptake. Insulin, EGF and IGF-1 exhibited a stimulation of glucose uptake for at least 24 h. Furthermore, the highest (p<0.05) synergistic effect was shown in EGF plus IGF-1 and the second synergistic effect in insulin plus EGF while no synergistic effect was found between insulin and IGF-1. However, the gut regulatory peptides neither potentiated nor inhibited the action of insulin on glucose uptake. Although growth factors did not modulates glucose uptake via increasing the rate of translation of the GLUT1 protein, RT-PCR analysis indicated that the growth factors significantly (p<0.05) increased the expression of GLUT1. The growth factors are therefore shown to be capable of modulating glucose uptake by transcription level with insulin in HC 11 cells.

Immobilization of Endo- and Exoinulinase on Vinylsulfone Activated Agarose (Vinylsulfone Activated Agarose 에 Endo- 및 Exoinulinase의 고정화)

  • 한상배;송근섭;정용섭;손희숙;우순자;엄태봉
    • Microbiology and Biotechnology Letters
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    • v.20 no.1
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    • pp.20-24
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    • 1992
  • In order to reuse inulinase effectively, a method for immobilizing both endo- and exoinulinase to vinylsulfone activated agarose via covalent bond was investigated. The immobilized enzyme preparation had, respectively, 400 U for exoinulinase activity and 80 U for endoinu- Iinase activity per gram gel. A thermal stability by immobilization had increased in the case of exoinulinase. Optimum pHs for two immobilized enzymes were 4.4 to 5.0. Synergistic effect which depends on mixed ratio of two immobilized enzymes was the best when the mixed ratio of endo/exo lay between 0.1 and 0.5, and its activity of the mixed enzyme increased 1.7 times as compared to that of each immobilized enzyme. Inulinase activities of both of the immobilized enzymes did not change during 20 times experimental runs in a batch reactor.

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Rheological Differences of Waxy Barley Flour Dispersions Mixed with Various Gums

  • Kim, Chong-Yeon;Yoo, Byoungseung
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.56-61
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    • 2017
  • Rheological properties of waxy barley flour (WBF) dispersions mixed with various gums (carboxyl methyl celluleose, guar gum, gum arabic, konjac gum, locust bean gum, tara gum, and xanthan gum) at different gum concentrations were examined in steady and dynamic shear. WBF-gum mixture samples showed a clear trend of shear-thinning behavior and had a non-Newtonian nature with yield stress. Rheological tests indicated that the flow and dynamic rheological parameter (apparent viscosity, consistency index, yield stress, storage modulus, and loss modulus) values of WBF dispersions mixed with gums, except for gum arabic, were significantly higher than those of WBF with no gum, and also increased with an increase in gum concentration. In particular, konjac gum at 0.6% among other gums showed the highest rheological parameter values. Tan ${\delta}$ values of WBF-xanthan gum mixtures were lower than those of other gums, showing that there is a more pronounced synergistic effect on the elastic properties of WBF in the presence of xanthan gum. Such synergistic effect was hypothesized by considering thermodynamic compatibility between xanthan gum and WBF. These rheological results suggest that in the WBF-gum mixture systems, the addition of gums modified the flow and viscoelastic properties of WBF, and that these modifications were dependent on the type of gum and gum concentration.

Joint Toxic Action of Insecticide Mixtures to the Cupermethrin-and Pirimicarb-Selected Strains of Green Peach Aphid(Myzus pericae Sulzer) (Cypermethrin과 Pirimicarb 저항성계통 복숭아혹잔딧물에 대한 살충제문의 연합독작용)

  • 안용준;김길하;최승윤
    • Korean journal of applied entomology
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    • v.28 no.1
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    • pp.32-36
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    • 1989
  • The joint toxic action of mixtures of cypermethrin or pirimicarb with one of other insecticides (acephate, cypermethrin, demeton-S-methyl and pirimicarb) on the cypermethrin or picimicarb-selected green peach aphid (Myzus persicae Sulzer)was investigated. The responses depended on the choice and ratios of insecticide combination. In the cypermethrin-selected strain bioas-say, mixtures of test insecticides showed no synergistic effect. On the other hand, the maxi-mum synergistic effects for the pirimicarb-selected strain were obtained at the 8 : 2 ratio of pirimicarb and demeton-S-methyl exhibited antagonistic effect.

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Synergistic Effect in Mosquitocidal Activity of Crystal Proteins from Bacillus thuringiensis NT0423 Transformed with cryIVD Gene (cryIVD 유전자로 형질전환된 Bacillus thuringiensis NT0423 균주 내독소 단백질의 모기 유충에 대한 독성의 상승효과)

  • 박현우;유용만;오현우;진병래;김인기;강석권
    • Korean journal of applied entomology
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    • v.35 no.1
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    • pp.85-90
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    • 1996
  • Bacillus thuringiensis NT0423 produces quite a typical bipyramidal crystals of a common major band of ca. 130 kDa, and has dual specificity against Lepidoptera and Diptera. To enforce the Diptera-toxicity of B. thuringiensis NT0423, cryND gene was transformed 30 B. thuringiensis NT0423. The transfonnant B. thuringiensis PT1227 was obtained from introduction of pCGl0 into B. thuringiensis NT0423 by electroporation. The result showed that cryND and resident crystal protein genes in transformant were stably expressed with its own shape. Furthermore, the toxicity of B. thuringiensis PT1227 against Diptera was highly enforced, suggesting that the enforced toxicity of B. thuringiensis PT1227 was due to synergistic effect of both introduced and resident crystal proteins in transformant.

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Synergistic Antibacterial Activity of Ecklonia cava Extract against Anti-biotic Resistant Enterococcus faecalis (항생제 내성 Enterococcus faecalis에 대한 감태(Ecklonia cava) 추출물의 항균 시너지 효과)

  • Kim, Seung-Yong;Kim, Young-Mog;Kim, Eunjung;Lee, Myung-Suk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.1
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    • pp.51-57
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    • 2015
  • With continuing demand for the development of new, effective and safe therapies, an investigation was carried out to test the efficacy of an antibacterial agent derived from marine edible seaweed. The methanolic extract of Ecklonia cava from marine edible seaweed evinced potential antibacterial activity against Enterococcus faecalis. Among five solvent-soluble fractions of E. cava methanolic extract, the ethyl acetate soluble extract (EtOAc) exhibited the strongest antibacterial activity, with a MIC value of $128{\mu}g/mL $ against E. faecalis strains. Furthermore, a synergistic antibacterial effect between an antibiotic and the EtOAc fraction was assessed using fractional inhibitory concentration (FIC) indices. A combination of ciprofloxacin and the EtOAc fraction resulted in a ${\sum}FIC_{min}$ range of 0.188 and ${\sum}FIC_{max}$ of 0.508 to 563, suggesting that the ciprofloxacin-EtOAc fraction of E. cava combination resulted in an antibacterial synergy effect against E. faecalis.

Soot and PAH Formation Characteristic of Concentric Co-Flow Diffusion Flames (이중동축류 확산화염에서의 매연 및 PAH 생성 특성)

  • Lee, Won-Nam;Nam, Youn-Woo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.2
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    • pp.178-185
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    • 2005
  • The synergistic effect of ethylene/propane mixture on soot formation is studied experimentally using a concentric co-flow diffusion burner, which provides the stratified fuel mixture. The soot volume fraction, soot particle diameter, number density and PAH concentrations are measured with various fuel supply configurations and compared to the homogeneously mixed case. When propane is supplied through the inner nozzle, an increase of soot formation is observed. However, when propane is supplied through the outer nozzle, a decrease is observed. The reaction path of PAH's formed from the pyrolysis process of propane is likely to be responsible to the observed differences. When propane is supplied through the outer nozzle, PAH's are formed in the relatively near oxidation region and exposed to the oxidization environment; on the other hand, when propane is supplied through the inner nozzle, PAH's are not likely to be oxidized and thus get involved in soot formation process. The synergistic effect in ethylene/propane diffusion flames is found to be affected not only by the com position of the mixture but also by the way of mixing.

The Synergistic Effect of Nitrogen and Ni2O3 over TiO2 Photocatalyst in the Degradation of 2,4,6-Trichlorophenol Under Visible Light

  • Hu, Shaozheng;Li, Fayun;Fan, Zhiping
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4052-4058
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    • 2012
  • The composite photocatalyst, N-$TiO_2$ loaded with $Ni_2O_3$, was prepared by $N_2$ plasma treatment. X-ray diffraction, X-ray fluorescence, $N_2$ adsorption, UV-vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared $TiO_2$ samples. The results indicated that the band gap energy was decreased obviously by nitrogen doping, whereas loading of $Ni_2O_3$ did not influence the band gap and visible light absorption. The photocatalytic activities were tested in the degradation of 2,4,6-trichlorophenol (TCP) under visible light. The photocatalytic activity and stability of composite photocatalyst were much higher than that of catalyst modified with nitrogen or $Ni_2O_3$ alone. The synergistic effect of doping nitrogen and $Ni_2O_3$ over $TiO_2$ was investigated.