• Title/Summary/Keyword: Synergistic response

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A RELATIONAL MODEL IN RESPONSE DATA ANALYSIS

  • Lee, Chun-Jin
    • Journal of applied mathematics & informatics
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    • v.6 no.3
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    • pp.953-959
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    • 1999
  • In modern applications of response data analysis, it has been found that there are stimuli which are independent for some com-binations of levels antagonistic for other and synergistic for some other combinations of levels. Obviously the classical models of stimuli re-sponse function fail to portray such inconsistent behaviour of the stim-uli. The classical model also fail to represent response functions of increasingly synergistic stimuli. Thus it has become necessary to build another type of models to represent relations of both synergistic and an-tagonistc for some combination of levels. This paper will propose a new model that can well explain such inconsistent behaviour of two jointly acting stimuli.

Periplanetasin-2 Enhances the Antibacterial Properties of Vancomycin or Chloramphenicol in Escherichia coli

  • Lee, Heejeong;Hwang, Jae Sam;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • v.31 no.2
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    • pp.189-196
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    • 2021
  • Periplanetasin-2 from cockroach exhibits broad-spectrum antimicrobial activity. The underlying antibacterial mechanisms rely on the stimulation of reactive oxygen species overproduction to induce apoptotic cell death. A promising strategy to increase the bioavailability of periplanetasin-2 involves reducing the dose through combination therapy with other antibacterials that show synergistic effects. Thus, the synergistic antibacterial activity of periplanetasin-2 with conventional antibacterial agents and its mechanisms was examined against Escherichia coli in this study. Among the agents tested, the combinations of periplanetasin-2 with vancomycin and chloramphenicol exhibited synergistic effects. Periplanetasin-2 in combination with vancomycin and chloramphenicol demonstrated antibacterial activity through the intracellular oxidative stress response. The combination with vancomycin resulted in the enhancement of bacterial apoptosis-like death, whereas the combination with chloramphenicol enhanced oxidative stress damage. These synergistic interactions of periplanetasin-2 can help broaden the spectrum of conventional antibiotics. The combination of antimicrobial peptides and conventional antibiotics is proposed as a novel perspective on treatments to combat severe bacterial infection.

Interaction between Brassinolide and Auxins on Bioassays (Brassinolide와 Auxin과의 상호작용의 생물검정에 의한 평가)

  • Choi, Chung-Don;Kim, Soon-Chul;Lee, Soo-Kwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.1
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    • pp.58-64
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    • 1990
  • This study was conducted to investigate the interaction effect of a new plant growth regulator brassinolide and auxins using several bioassay methods such as rice lamina inclination test, oat coleoptile segment growth test and radish hypocotyl elongation test. For rice lamina inclination test, the antagonistic response showed at low concentration combinations of homobrassinolide and auxins (IAA and 2,4-D), while the combinations of high concentration responsed mostly synergistic or additive effects, IAA was generally higher than 2,4-D for combination effect with homobrassinolide. For oat coleoptile segment growth test, the synergistic effect showed at IAA concentrations less than 0.1ppm while additive response exhibited above 0.3ppm regardless of homobrassinolide concentrations. In radish hypocotyl elongation test, the interaction response varied with cotyledon. The sections removed cotyledon showed mostly antagonistic effects, except for combination of homobrassinolide with IAA 3ppm. Interaction responses were Quite different from bioassay methods, particularly using experimental materials: antagonistic responses were usually shown at the section that attached growing point while these for sections that removed growing point were responded synergistic or additive effect due to unstable endogenous hormones.

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Optimization of Mixing Ratio to Improve Antioxidant Activity of Aged Garlic with Pine Needle Using Response Surface Methodology

  • Park, Jae-Hee;Shin, Eunji;Park, Eunju
    • Preventive Nutrition and Food Science
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    • v.22 no.3
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    • pp.241-245
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    • 2017
  • Aged garlic has been reported to possess beneficial pharmacological activities, including anti-stress and anti-fatigue properties, and to exert protective effects on the cardiovascular system and liver. Pine needles are widely used in folk medicine and as food additives owing to their pharmacological properties such as anti-aging and anti-inflammatory effects. It has long been known that combining certain phytochemicals with other phenols or organic acids can produce synergistic effects. Therefore, the purpose of this study was to develop an optimal formula of aged garlic with added pine needle powder for improved antioxidant activity using the statistical technique of response surface methodology. The antioxidant activities of aged garlic mixed with pine needle powder were confirmed by measuring oxygen radical absorbance capacity and total polyphenol content. An optimized antioxidant formula was identified that contained 5.08 g aged garlic and 1.97 g pine needle powder. The antioxidant activities of the mixture prepared using this optimal formula were significantly higher than the predicted values according to an additive model. Hence, this study confirms that the addition of pine needle powder to aged garlic can improve its antioxidant activity. This study demonstrated an optimal mixing ratio to produce an aged garlic product with improved functionality through the addition of pine needle powder that could be successfully employed by the food industry to prepare functional foods.

Study on the Analgesic Effects of Several Herbal Drugs and Their Synergistic Effects (수종 한약재의 진통효과 및 약물의 배합에 따른 Synergy효과에 관한 연구)

  • Kwon, Oh-Gyu;Kim, Kwang-Joong
    • Journal of Oriental Physiology
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    • v.14 no.2 s.20
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    • pp.127-137
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    • 1999
  • The current experiment was carried out to investigate the analgesic effects of several herbal drugs in acetic acid - induced pain model. In a single drug group : after administration of herbal drugs(1g/kg or 3g/kg) orally for 30 minutes, 1% acetic acid $(250{\mu}l)$ was administered into abdominal cavity of mouse. And then the number of times of writhing response was measured for 30 minutes. In a combination drug group : after administration of herbal drugs (1g/kg and it's compound 2g/kg) orally for 30 minutes, 1% acetic acid $(250{\mu}l)$ was administered into abdominal cavity of mouse. And then the number of times of writhing response was measured for 30 minutes. The results were summarized as follows; 1. Water extracts of Akebiae caulis(木通) and Stephaniae tetrandrae radix(防己) decreased significantly the number of writhing response. 2. Methanol extracts of Achyranthis bidentatae radix(牛膝), Carthami flos(紅花), Akebiae caaulis(木通), Stephaniae tetrandrae radix(防己), Myrrha(沒藥), Corydalidis tuber(玄胡索) and Persicae semen(桃仁) decreased significantly the number of writhing response. 3. Water extracts of Achyranthis bidentatae radix(牛膝) plus Akebiae caulis(木通), Achyranthis bidentatae radix(牛膝) plus Stephaniae tetrandrae radix(防己) and Achyranthis bidentatae radix(牛膝) plus Ledebouriellae radix(防風) decreased the number of writhing response significantly. 4. Methanol extracts of Achyranthis bidentatae radix(牛膝) plus Myrrha(沒藥), Achyranthis bidentatae radix(牛膝) plus Stephaniae tetrandrae radlx(防己) and Achyranthis bidentatae radix(牛膝) plus Ledebouriellae radix(防風) decreased the number of writhing response significantly.

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Synergistic anticancer effects of timosaponin AIII and ginsenosides in MG63 human osteosarcoma cells

  • Jung, Okkeun;Lee, Sang Yeol
    • Journal of Ginseng Research
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    • v.43 no.3
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    • pp.488-495
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    • 2019
  • Background: Timosaponin AIII (TA3) is a steroidal saponin extracted from Anemarrhena asphodeloides. Here, we investigated the anticancer effects of TA3 in MG63 human osteosarcoma cells. TA3 attenuates migration and invasion of MG63 cells via regulations of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are involved with cancer metastasis in various cancer cells. TA3 reduced enzymatic activities and transcriptional expressions of MMP-2 and MMP-9 in MG63 cells. TA3 also inhibited Src, focal adhesion kinase, extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), p38, ${\beta}-catenin$, and cAMP response element binding signaling, which regulate migration and invasion of cells. TA3 induced apoptosis of MG63 cells via regulations of caspase-3, caspase-7, and poly(ADP-ribose) polymerase (PARP). Then, we tested several ginsenosides to be used in combination with TA3 for the synergistic anticancer effects. We found that ginsenosides Rb1 and Rc have synergistic effects on TA3-induced apoptosis in MG63 cells. Methods: We investigated the anticancer effects of TA3 and synergistic effects of various ginseng saponins on TA3-induced apoptosis in MG63 cells. To test antimetastatic effects, we performed wound healing migration assay, Boyden chamber invasion assays, gelatin zymography assay, and Western blot analysis. Annexin V/PI staining apoptosis assay was performed to determine the apoptotic effect of TA3 and ginsenosides. Results: TA3 attenuated migration and invasion of MG63 cells and induced apoptosis of MG63 cells. Ginsenosides Rb1 and Rc showed the synergistic effects on TA3-induced apoptosis in MG63 cells. Conclusions: The results strongly suggest that the combination of TA3 and the two ginsenosides Rb1 and Rc may be a strong candidate for the effective antiosteosarcoma agent.

Synergistic inhibition of mesothelioma cell growth by the combination of clofarabine and resveratrol involves Nrf2 downregulation

  • Lee, Yoon-Jin;Im, Jae-Hyuk;Lee, David M.;Park, Ji-Sung;Won, Seong Youn;Cho, Moon-Kyun;Nam, Hae-Seon;Lee, Yong-Jin;Lee, Sang-Han
    • BMB Reports
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    • v.45 no.11
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    • pp.647-652
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    • 2012
  • We previously reported that MSTO-211H cells have a higher capacity to regulate Nrf2 activation in response to changes in the cellular redox environment. To further characterize its biological significance, the response of Nrf2, a transcription factor that regulates ARE-containing genes, on the synergistic cytotoxic effect of clofarabine and resveratrol was investigated in mesothelioma cells. The combination treatment showed a marked growth-inhibitory effect, which was accompanied by suppression of Nrf2 activation and decreased expression of heme oxygenase-1 (HO-1). While transient overexpression of Nrf2 conferred protection against the cytotoxicity caused by their combination, knockdown of Nrf2 expression using siRNA enhanced their cytotoxic effect. Pretreatment with Ly294002, a PI3K inhibitor, augmented the decrease in HO-1 level by their combination, whereas no obvious changes were observed in Nrf2 levels. Altogether, these results suggest that the synergistic cytotoxic effect of clofarabine and resveratrol was mediated, at least in part, through suppression of Nrf2 signaling.

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.

The Synergistic Effect of Additional Ethanol Exposure on Quercetin-induced Vasorelaxation in a Vasoconstrictor-dependent Manner (Quercetin에 의한 혈관이완효과에 대한 알코올의 추가적인 역할)

  • Jin, Young-Bae;Je, Hyun-Dong
    • YAKHAK HOEJI
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    • v.54 no.5
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    • pp.392-397
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    • 2010
  • The aim of present study was to investigate the possible influence and related mechanism of additional alcohol on the flavonoid- induced arterial relaxation. Agonist-induced vascular smooth muscle contractions involve the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in quercetin-induced relaxation cotreated with alcohol in rat aortae contracted with phorbol ester, fluoride or thromboxane $A_2$ mimetic U-46619. We hypothesized that cotreated alcohol plays a role in vascular relaxation evoked by quercetin in rat aortae. Endothelium-denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Quercetin inhibited phorbol ester, fluoride or thromboxane $A_2$-induced contraction regardless of endothelial function. However, alcohol didn't decrease any agonist-induced contraction. Interestingly, only in thromboxane $A_2$-induced contraction, synergistic results were observed in aortae denuded and cotreated with quercetin and alcohol suggesting that additional pathways different from antioxidation or endothelial nitric oxide synthesis might be involved in the vasorelaxation. In conclusion, in the agonists-contracted rat aortae, quercetin and alcohol together showed synergistic response regardless of endothelial function in an agonist-dependent manner.

Cell Biological Studies on Growth and Development Effect of$Ca^{2+}$ and polyamine of $\beta-glucan$synthetase activity in carrot root protoplast (생체생장에 관한 세포생물학적 연구 당근 뿌리의 원형질체에서 polyamine과 $Ca^{2+}$$\beta-glucan$ synthetase 활성도에 미치는 영향)

  • 이순희
    • Journal of Plant Biology
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    • v.30 no.3
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    • pp.173-179
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    • 1987
  • The effect of polyamine, Ca2+ and calmodulin on GS ($\beta$-glucan synthetase) activity was studied in Daucus carota root. The Ca2+ is shown to have no effect on the GS activity whereas the GS II activity is increased in response to increase in concentration of the Ca2+. When the protoplasts are cultured, for 4 days, the GS II activity increases as a tunction of time and reachs a maximum after 3 days at a time when the network of cellulose microfibrils is known to be synthesized. The effect of the Ca2+ and 1mM spermine on the GS II activity turns out to be synergistic, especially more synergistic at lower concentration of the Ca2+. The GS II activity seems to be enhanced by the Ca2+. The GS II activity in the protoplast treated by the calcium channel blocker, verapamil, turns out to be lower than that of the control. Cumulative results suggest that the Ca2+ stimulates the cell wall regeneration via enhancement of the GS II activity responsible for synthesizing the cell wall component throught synergistic effect with spermine.

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