• Corrosion Science and Technology
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• v.15 no.4
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• pp.171-181
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• 2016

In this work, synergistic corrosion inhibition effect of nitrite and 3 kinds of ethanolamines on ductile cast iron using chemical and electrochemical methods was evaluated. This work attempts to clarify the synergistic effect of nitrite and ethanolamines. The effects of single addition of TEA, DEA, and MEA, and mixed addition of nitrite plus TEA, DEA or MEA on the corrosion inhibition of ductile cast iron in a tap water were evaluated. A huge amount of single addition of ethanolamine was needed. However, the synergistic effect by mixed addition was observed regardless of the combination of nitrite and triethanolamines, but their effects increased in a series of MEA + nitrite > DEA + nitrite > TEA + nitrite. This tendency of synergistic effect was attributed to the film properties and polar effect; TEA addition couldn't form the film showing high film resistance and semiconductive properties, but DEA or MEA could build the film having relatively high film resistance and n-type semiconductive properties. Moreover, it can be explained that this behaviour was closely related to electron attractive group within the ethanolamines, and thus corrosion inhibition power depends upon the number of the electron attractive group of MEA, DEA, and TEA.

• Corrosion Science and Technology
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• v.16 no.3
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• pp.91-99
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• 2017

The objective of this work was to develop efficient synergistic inhibitor combinations comprising sodium nitrite ($NaNO_2$) and an inhibitor-blend code named (SN-50), keeping in view of their application in industrial cooling water systems. The electrochemical characteristics of the carbon steel working electrode in simulated cooling water (SCW), without and with the addition of different combinations of the inhibitors, were investigated using electrochemical impedance spectroscopy (EIS), open circuit potential (OCP). The electrode surface changes were followed by visual characterization methods. It was demonstrated in this study that all the combinations of the inhibitors exhibited synergistic benefit and higher inhibition efficiencies than did either of the individual inhibitors. The addition of SN-50 inhibitor to the SCW shifted the OCP to more anodic values and increased the polarization resistance ($R_p$) values of carbon steel at all applied concentrations. The higher the applied sodium nitrite concentration (in the protection concentration range), the higher the obtained $R_p$ values and the inhibition efficiency improved by increasing the inhibitor concentration.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.992-997
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• 2007

Cisplatin is a chemotherapeutic drug which is widely used for cancer therapy including cervical cancer. The purpose of this study is to elucidate synergistic effect of Cisplatin and Berberine on the apoptosis of HeLa cells and to determine whether oxidants are formed as part of apoptotic process. Apoptotic death of HeLa cells by cisplatin and berberine was confirmed by chromatin condensation of HeLa cells and flow cytometric analysis of intracellular ROS(reactive oxygen species) production. In MTT assay, Cell viability was decreased and enhanced ROS generation in combination of cisplatin and berberine significantly, as compared with cisplatin only. Synergistic effect of Cisplatin and Berberine on the inhibition of cell growth by apoptosis was clearly observed and ROS may play an important role in apoptosis. This effect suggest the possibility lowering the concentration of chemotherapeutic drugs, which alleviate the side effect of drugs.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.1015-1020
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• 2019

Staphylococcus aureus is a representative pathogenic bacterium carefully controlled in the dairy industry because it causes bovine mastitis and thus, can enter the dairy chain. Furthermore, the emergence of multi-drug resistant S. aureus is a big problem. We previously isolated a Lactococcus lactis strain producing a bacteriocin that exhibited strong antimicrobial activity against S. aureus. In this study, we investigated the synergistic inhibition of S. aureus by the bacteriocin and a bacteriophage (SAP84) which is specific to the organism. The bacteriocin (12.5-100 AU/mL) inhibited the growth of S. aureus KCTC 3881 in a dose-dependent manner, as did the bacteriophage SAP84 (0.001-1 MOI; multiplicity of infection). Co-treatment with the bacteriocin (100 AU/mL) and the bacteriophage (0.1 MOI) significantly inhibited the growth of S. aureus compared to each treatment alone (bacteriocin or bacteriophage), indicating the two components showed synergistic inhibition of S. aureus. Therefore, the bacteriocin and bacteriophage combination can be used as a good strategy for controlling pathogenic bacteria.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.591-594
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• 2019

Some strains of Escherichia coli are categorized as pathogenic bacteria and alternative antimicrobials including bacteriophages for controlling these bacteria have been studied. In this study we screened antimicrobial candidates that present synergistic inhibition of the growth of E. coli DH5α as a model when co-treated with the bacteriophage ECP27 to target the bacteria. As candidates, CaCl₂, lactic acid, and citric acid were tested. CaCl₂ showed a synergistic inhibition against the strain by dose-dependent manner at 6 h of incubation but the viable cell count was recovered at 12 h. However, lactic acid and citric acid at 30 mM concentration showed synergistic inhibitions at 6 h of incubation and cleared the viable cells of E. coli DH5α at 12 h when co-treated with the bacteriophage even though lactic acid or citric acid alone was effective. Therefore, co-treatment using the bacteriophage and organic acids such as lactic acid and citric acid can be a solution for synergistic inhibition of the growth of E. coli.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.23-27
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• 1988

In order to investigate the combined effect of potassium sorbate and sodium benzoate and the synergistic effect of sodium chloride on bacterial cell growth inhibition, Bacillus subtilis was cultured with or without shaking in tryptone-glucose-yeast extract broth containing 0.1% potassium sorbate and/or 0.03% sodium benzoat, which are equivalent to half of the maximum permissible levels, respectively. The combined treatment of the two preservatives did not show any synergistic effect of tne growth inhibition of B. subtilis. Addition of 2% sodium chloride, however, showed remarkable synergistic effect on the growth inhibition of the bacterium by potassium sorbate.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.183-190
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• 2000

Medicinal plants with synergistic effects on growth inhibition of canter cells under oxidative stress were screened in this study. Methanol extracts from 51 natural medicinal plants which were reported to have anticancer effort on hepatoma stomach cancer or colon cancers which are frequently found in Korean, were prepared and screened for their synergistic activity on growth inhibition of cancer cells under chemically-induced oxidative stress by using MTT assay. Twenty seven samples showed synergistic activity on the growth inhibition in various extent under chemically-induced oxidative stress. Among those samples, eleven samples such as Melia azedarach, Agastache rugosa, Catalpa ovata, Prunus persica, Sinomenium acutum Pulsatilla koreana, Oldenlandia diffusa, Anthriscus sylvestris, Schizandra chinensis, Gieditsia sinensis, Cridium officinale, showed decrease in $IC_{50}$ values more than 50%, other 16 samples showed decrease in $IC_{50}$ values between 50-25%, compared with the value acquired when medicinal plant sample was used alone. Among those 11 samples, extract of Catalpa ovata showed the highest activity. $IC_{50}$ values were decrease to 61% and 28% when carcinoma cells were treated with Catalpa ovata extract in combination of 75 and 100 uM of hydrogen peroxide, respectively.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.229-232
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• 2018

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.145-156
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• 2023

Many skin diseases are caused by microbial infections. Representative pathogenic fungus and bacterium that cause skin diseases are Candida albicans and Staphylococcus aureus, respectively. Malassezia pachydermatis is a fungus that causes animal skin diseases. In this study, we propose a method for removing pathogenic microorganisms from the skin using relatively safe edible herbal extracts. Herbal extracts were screened for skin health through the removal of pathogenic microorganisms, and combinations for effective utilization of the screened extracts were identified. In this study, among methanol extracts of 240 edible plants, C. albicans, S. aureus, and M. pachydermatis were killed by extracts of 10 plants: Acori Gramineri Rhizoma, Angelicae Tenuissimae Radix, Cinnamomi Cortex, Cinnamomi Ramulus, Impatientis Semen, Magnoliae Cortex, Moutan Cortex Radicis, Phellodendri Cortex, Scutellariae Radix, and Syzygii Flos. By evaluating the synergistic antifungal activities against C. albicans using all 45 possible combinations of these 10 extracts, five new synergistic antifungal combinations, Acori Gramineri Rhizoma with Magnoliae Cortex extracts, Acori Gramineri Rhizoma with Phellodendri Cortex extracts, Angelicae Tenuissimae Radix with Magnoliae Cortex extracts, Magnoliae Cortex with Phellodendri Cortex extracts, and Phellodendri Cortex with Syzygii Flos extracts, were identified. By utilizing the selected extracts and five combinations with synergistic antifungal effects, this work provides materials and methods to develop new and safe methods for treating candidiasis using natural products.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.143-154
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• 2022

We isolated marine actinomycetes, strain D-5 which produces anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compound. Streptomyces sp. D-5 relatively grew well in the 20~25℃, pH 8.0, and NaCl 3.0%. The ethyl acetate extract of D-5 culture was separated by C₁₈ ODS open column and reverse phase HPLC to yield anti-MRSA compound. The molecular weight of this compound was determined to be 898 by a Liquid chromatograph-mass spectrometer (LC-MS). Compared with penicillin G, this compound showed significant anti-MRSA activity. It also exhibited an inhibition zone of 26 mm at a concentration of 64 ㎍/disk and an inhibition zone of 16 mm at a concentration of 16 ㎍/disk against the MRSA KCCM 40511. Furthermore, the co-treatment of HPLC peak 5 compound and vancomycin caused a more rapid decrease in MRSA cells than each compound alone. It showed 86.8% growth inhibition activity within 12 hours at a low concentration of 50 ㎍/mL during co-treatment, and 97.1% growth in-hibition activity within 48 hours against MRSA KCCM 40511. Taken together, our results suggest that Streptomyces sp. D-5 and its anti-MRSA compound could be employed as a potent agent in MRSA infection.