• Journal of Radiation Protection and Research
• /
• v.35 no.3
• /
• pp.99-104
• /
• 2010

The potential ability of environmental temperature to enhance the effect of microwave radiation (7 GHz) was experimentally studied for rabbit heating after simultaneous application of both agents. The tested ambient temperatures (30 and $38^{\circ}C$) didn't exert a considerable influence upon rabbit heat homeostasis after the used duration of exposure (3 hours and 15 minutes, correspondingly). The synergistic interaction of microwave irradiation and ambient temperature was demonstrated for rabbit heating. Power flux density of microwave irradiation was shown to be a determinant of the synergistic interaction effectiveness. For the fixed ambient temperature ($30^{\circ}C$), the synergism was shown to be observed only within a definite power flux density ($0-100\;mW{\cdot}cm^{-2}$), inside of which there was an optimal intensity ($20\;mW{\cdot}cm^{-2}$), which maximized the synergistic effect. Any deviation of the power flux density from the optimal value resulted in a reduction of the synergy. It is concluded that any assessment of the health or environmental risks should take into account the synergistic interaction between ambient temperature and microwave radiation.

• Korean Journal of Environmental Biology
• /
• v.27 no.2
• /
• pp.140-145
• /
• 2009

All organisms are being exposed to harmful factors present in the environmental. The combined action of various factors is a distinguishing feature of modern life. An interaction between two chemicals is considered as synergistic when the effect produced is greater than the sum of the two single responses. The biological effects due to the combined action of ionizing radiation with the other factor are hard to estimate and predict in advance. In the current study, we investigated the synergistic effects between ionizing and $HgCl_2$ using fish hepatoma cells (PLHC-1 cells). The results showed a dramatic decrease of cell viability after simultaneous treatment of PLHC-1 cells with ionizing radiation and $HgCl_2$. Neiither of the two had any cytotoxic effect when treated alone. The cytotoxicity of ionizing radiation was enhanced in the presence of $HgCl_2$. The synergistic effects were observed after exposure of the PLHC-1 cells to ionizing radiation combined with $HgCl_2$. The synergistic interaction was due to an increase of irreversibly damaged cells after the combined exposure. Analysis of the extent of synergistic interaction enables to make quantitative estimation of irreversibly damaged cells after the combined exposure. The present study suggests that PLHC-1 cells can serve as rapid screening tools for detecting the toxicity of harmful factors.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.402-407
• /
• 2008

The synergistic antimicrobial effect of Achyranthes japonica Nakai (AJN) and Bifidobacterium extracellular factors against Clostridium difficile were measured using a turbidity method. Each broth supernatant of Bifidobacterium infantis ($68.8{\pm}0.02%$) and Bifidobacterium adolescentis ($33.2{\pm}0.2%$) obtained by adding ethyl acetate soluble fractionate from A. japonica Nakai ethanolic extracts (AJNEA, 100 ppm, no inhibition) showed high synergistic antimicrobial activity against C. difficile. In addition, the antimicrobial activity in a laboratory medium and yogurt products against C. difficile were evaluated. In yogurt prepared with a starter 5 (Lactobacillus acidophilus: Streptococcus thermophilus: B. adolescentis =1 : 1 : 1) and a starter 4 (L. acidophilus: S. thermophilus: B. infantis=1 : 1 : 1) and 0.5% AJNEA powder, high antimicrobial effects were recorded that measured 79.0 and 65.2%, respectively. The results indicated the potential of AJN extract for use as an antimicrobial agent. In addition, the efficiency of the antimicrobial activity of the extracts was further improved in combination with lactic acid bacteria, which suggests that they have the potential to be used as a highly effective antibiotic-tolerant microorganism prevention system. Such a strategy can be used for alternative drugs or functional food additives for treatment of antibiotic-associated diarrhea.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.11
• /
• pp.3928-3932
• /
• 2011

We synthesized peptide-resin conjugates (1 and 2) by immobilizing ${\beta}$-sheet antibacterial peptide and ${\alpha}$ helical antibacterial peptide on PEG-PS resin, respectively. Conjugate 1 showed considerable antibacterial activity in various conditions, whereas conjugate 2 did not exhibit antibacterial activity. The growths of various bacteria were inhibited by conjugate 1 even at lower concentrations than MIC. Conjugate 1 killed bacteria at MIC and had a potent synergistic effect with current antibacterial agents such as vancomycin and tetracycline, respectively. Overall results indicate that polymer surface modification using antibacterial ${\beta}$ sheet peptide is a powerful way to prevent microbial contamination on polymer surfaces.

• Korean Journal of Pharmacognosy
• /
• v.22 no.1
• /
• pp.45-50
• /
• 1991

The combined effect of berberine isolated from the bark of Phellodendron amurense and some antibiotics was evaluated in order to measure the antibiotic activities. In this study, in the presence of streptomycin, tetracycline, cephradine as antibiotics, Staphylococcus aureus, Escherichia coli, Shigella sonnei as microorganisms were grown in an Automated Microbiology System. In case of Staphylococus aureus, combination with berberine and cephardine resulted in the strongest synergistic activity and in case of Escherichia coli and Shigella sonnei, combination with berberine and streptomycin resulted in the strongest synergistic activity. The combination with berberine and antibiotics increased the antibiotic activities, thereby showing a synergistic action.

• CELLMED
• /
• v.12 no.3
• /
• pp.13.1-13.3
• /
• 2022

The aim of this study was to evaluate the synergistic effect of Samulnori and Ajaeng combination in music therapy. Samulnori is the Korea's most successful traditional music. The Ajaeng, Korean traditional string instrument, generally plays the bass part in ensemble music. However, we have tried a new kind of musical style. (As you can see in the Youtube, https://youtu.be/QHIciJTTY0w). Samulnori and Ajaeng combination of our style have not been tried by any other musicians in Korea. Results from this study showed that Samulnori-induced excitation and Ajaeng-induced dynamics probably contributed to the synergistic effect of Samulnori and Ajaeng.

• Journal of Haehwa Medicine
• /
• v.4 no.1
• /
• pp.211-223
• /
• 1995

The antitumor effect of 柴胡(Bupleuri Radix : BP), 茵陳(Artemisiae capillaris Herba; ACH) 및 蒲公英(Taraxaci Herba; TH) and 蒲公英 EE層(Ethyl ether layer of TH; EETH) on human hepatocytes such as Hep G2, PLC and Hep 3B, and synergistic action with the anticancer drugs, that is, mitomycin(MMC), cisplatin(CPT) and 5-fluorouracil(5-FU) were studied by the method of MTT. The results were obtained as follows: 1. $IC_{50}$ against Hep G2, PLC and Hep 3B was $15.5{\mu}g/ml$, $25.4{\mu}g/ml$ and 31.25 in MMC, $92.5{\mu}g/ml$, $50.2{\mu}g/ml$ and $62.5{\mu}g/ml$ in CPT and $125{\mu}g/ml$ in 5-FU respectively. 2. Cytotoxic effect on Hep G2 was obvious in BP-treated group, synergistic action was most effective in TH-treated group or with MMC. 3. Cytotoxic effect on Hep 3B was obvious in ACH-treated group, synergistic action was most effective in ACH-treated group or with MMC. 4. Cytotoxic effect on PLC was obvious in ACH-treated group, synergistic action was most effective in TH-treated group or with MMC. From above results it was concluded that ACH showed the best antitumor effect against PLC and Hep 3B, BP aganst Hep G2 and also synergistic effect was most effective with MMC, which indicates that it is necessary to seperate the antitumor substances in ACH.

• Natural Product Sciences
• /
• v.25 no.4
• /
• pp.311-316
• /
• 2019

Artocarpus heterophyllus has been used as traditional medicine. This plant is one of the sources of flavonoid. Flavonoid compounds possessed a wide range of biological properties including anticancer. This study was performed to investigate the cytotoxic effect of flavonoids from A. heterophyllus on H460 and MCF-7 cell lines. The interaction of flavonoids and cisplatin against tested cancer cells was also evaluated. MTT assay was used to determine the cytotoxic effect of flavonoid. Isobologram analysis was selected to evaluate the synergistic effect between flavonoid and cisplatin, their interaction was then confirmed using AO/PI staining method. Amongst of flavonoid compounds, artocarpin exhibited strong cytotoxic effect on both MCF-7 and H460 cell lines with IC₅₀ values of 12.53 ㎍/mL (28.73 μM) and 9.77 ㎍/mL (22.40 μM), respectively. This compound enhanced anticancer activity of cisplatin against H460 and MCF-7. The combination produced a synergistic effect on H460 and MCF-7 cell lines with a combination index (CI) values of 0.2 and 0.18, respectively. The AO/PI stained demonstrated that the combination of artocarpin and cisplatin caused morphological changes that indicated apoptosis. Moreover, artocarpanone also significantly increased cytotoxic effect of cisplatin compared to its single concentration with CI below than 1. This result suggested the potency of flavonoid named artocarpin to enhance the anticancer activity of cisplatin on H460 and MCF-7 cell lines.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.1
• /
• pp.50-54
• /
• 2000

The elongation of mesocotyl and coleoptile plays important roles in the seedling emergence and stand establishment of dry direct-seeded rice. Experiments were carried out to elucidate the effects of seed-presoaking treatments of GA$_3$ and some inorganic salts on the mesocotyl, and coleoptile elongation of rice. Seed-soaked GA$_3$ promoted the elongation of mesocotyl, but little effect on the coleoptile elongation. The stimulation effects of GA$_3$ were found to be enhanced by addition of CaCl$_2$ However, the sole treatment of CaCl$_2$ showed no stimulating effect on the mesocotyl and coleoptile elongation. Mesocotyl elongation was most prominent in the combined treatments of 50ppm GA$_3$ with 100 mM CaCl$_2$. The synergistic effects of GA$_3$ and CaCl$_2$ on mesocotyl elongation varied with varietal groups. The stimulating effects of GA$_3$ were enhanced significantly by the addition of CaCl$_2$ in japonica varieties, Dongjinbyeo, Ilpumbyeo and Milyang 95, and tall indica variety, Labelle, but not in semidwarf Tongil type varieties, Tongilbyeo, Milyang 23, and Nampungbyeo, and semi-dwarf indica, Short Labelle. The promoting effects of GA$_3$ on the mesocotyl elongation were decreased in proportion to the lowered osmotic potential by PEG 6000 on the contrary to CaCl$_2$ This implies that the synergistic effects of CaCl$_2$ with GA$_3$ on mesocotyl elongation was not caused by osmotic potential lowered by CaCl$_2$ addition but by the salt itself. Salts such as Ca(NO$_3$)$_2$, MgCl$_2$ BaCl$_2$, NaCl, KCl and KNO$_3$ showed the synergistic effects with GA$_3$ on mesocotyl elongation as well. The degree of synergistic effects showed no differences among salts tested, implying that there is no specificity of ions constituting the salts.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.5
• /
• pp.858-864
• /
• 2007

This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration(FIC) index. The sophoraflavanone G+ampicillin(AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin(GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions(FIC index>4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half$\sim$one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.