• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.707-710
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• 2005

The antimicrobial activities of extracts from some of natural products and bacteriocins produced from lactic acid bacteria such as L. mesenteroides, L. citreum and P. pentosaceus have been investigated with using disc diffusion assay, challenge method and minimum inhibitory concentration method. The bacteriocin substances produced from L. mesenteroides, L. citreum and P, pentosaceus have shown strong antimicrobial activities against E. coli, S. aureus, P. aerugionosa, and B. subtillis while the extracts from phenonip and sandal wood have shown strong antimicrobial activities only against C. albicans. The bacteriocins produced from L. mesenteroides, L. citreum and P. pentosaceus could be a promising preservatives for cosmetics, pharmaceutical products and foods in future.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.111-122
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• 2017

Objectives: Coriolus versicolor is an edible mushroom with physiological activities that has been used in traditional medicine. The aim of this study was to investigate the antimicrobial activity of extracts obtained from Coriolus versicolor against oral pathogens. Methods: The antimicrobial activities of various extracts of Coriolus versicolor were examined by disc diffusion assay, and minimum inhibitory concentration (MIC) of these extracts were also was determined by broth dilution method. The growth inhibition effect of extracts was measured at 600 nm for 12 hrs against Streptococcus ratti, Streptococcus criceti, Aggregati--bacter actinomycetemcomitans, Actinomyces viscosus, and Actinomyces israelii. Results: Coriolus versicolor extracts showed antimicrobial activities against all nine oral pathogens through disc diffusion assay. The ethanol extract and ethyl acetate extract differed significantly compared with acetone extract against Streptococcus ratti, Streptococcus criceti, Actinomyces viscosus, Actinomyces israelii and Aggregatibacter actinomycetemcomitans (p<0.05). These extracts exhibited MIC ranges of 2.63 to >10.50 mg/ml against the tested bacteria. The ethanol extract from Coriolus versicolor showed lower MIC values of 2.63 to 5.25 mg/ml. According to the obtained growth curve, the extracts of Coriolus versicolor were more effective against Actinomyces viscosus. Conclusions: The acetone, ethanol, and ethyl acetate extracts from Coriolus versicolor showed antimicrobial activities against Streptococcus mutans, Staphylococcus aureus, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus ratti, Streptococcus criceti, Aggregatibacter actinomycetemcomitans, Actinomyces viscosus, and Actinomyces israeli.i Therefore, they could be considered as natural oral antimicrobial agents against oral pathogens.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.605-614
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• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.692-700
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• 2012

The antibacterial activity of the ethanol extract of Cornus officinalis against some bacteria related to foodborne illness and food spoilage was investigated. In the case of the disc diffusion assay, clear zones due to the inhibition of proliferation by Cornus officinalis extract were 8.5~18.3 mm at $4,000{\mu}g/disc$. The inhibitory effect of Cornus officinalis was as follows: Escherichia. coli ${\geq}$ Listeria monocytogenes ${\geq}$ E. coli O157:H7 > Bacillus cereus > Staphylococcus aureus > Pseudomonas aeruginosa > Salmonella typhimurium. In addition, the MIC of Cornus officinalis extract toward B. cereus was the lowest at 1,000 ppm. The extract inhibited the growth of E. coli, L. monocytogenes, E. coli O157:H7, and Bacillus cereus throughout the growth stage. However, the growth of P. aeruginosa, S. aureus, and S. typhimurium was only inhibited by the extract during the lag phase. The constituents of all cells tested were released, especially E. coli and E. coli O157:H7. Observation of the cells using SEM demonstrated a morphological change and disruption of cells in response to treatment with Cornus officinalis extract. Based on these findings, the ethanol extracts of Cornus officinalis showed strong antimicrobial activity against all tested bacteria, indicating that Cornus officinalis can be a useful natural antimicrobial reagent.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.135-139
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• 2016

Scrophularia ningpoensis hemsl has been traditionally used in China and Vietnam for treatment of bacteria, atopy, pimple, tonsillitis, angina and encephalitis for a long time. The main objectives of this study were to evaluate the antibacterial activity of the Scrophularia ningpoensis hemsl extract on biofilm formation of Klebsiella pneumoniae. Antibacterial activity was conducted using disc diffusion assay and minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were determined using the broth micro dilution method in accordance to Clinical and Laboratory Standards Institute guidelines(CLSI). Furthermore, cytotoxicity on L929 were assessed using animal cell culture for the proliferation test(MTT cell assay) and the biofilm forming capacity of the K. pneumoniae were determined using the colony forming unit (CFU) assay. The extract exhibited considerable antibacterial activity. K. pneumoniae was susceptible to the extract with the MIC and MBC of 0.1875 and $1.5mg/m{\ell}$ respectively. Cytoxicity test in L929 showed no sign of toxicity at the concentration of $0.75mg/m{\ell}$ and at the same concentration the extract caused inhibition of bacterial biofilm formation. The extract of Scrophularia ningpoensis hemsl possesses an in vitro antibacterial antibiofilm activities against K. pneumoniae, with no sign of cytoxicity on L929.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.3
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• pp.15-26
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• 2013

Objectives The aim of this study was to investigate antimicrobial activity of Huanggeumjakyak- tang water extract against MRSA. Methods The antibacterial activities of Huanggeumjakyak-tang were evaluated against 3 strains of Methicillin-resistant Staphylococcus aureus (MRSA) and 1 standard Methicillinsusceptible S. aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay was performed under dark. Results The MIC (minimum inhibitory concentration) of Huanggeumjakyak-tang water extract against S. aureus strains ranged from 1,000 to $2,000{\mu}g/ml$. So we confirmed that it has a strong antibacterial effect. Also the combinations of Huanggeumjakyak-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. Conclusions The results obtained in this study suggest that Huanggeumjakyak-tang water extract showed antibacterial effect against MRSA, and it also showed reducing effect on the side-effect problems that are the major weak points of traditional antibiotics.

• Korean Journal of Pharmacognosy
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• v.50 no.2
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• pp.112-117
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• 2019

In this study, extracts of bark from Ulmus davidiana var. japonica and its fractions were investigated the antioxidative, antibacterial and tyrosinase inhibition activity for physiological activity towards functional applications. In the measurement of DPPH radical scavenging activity, the ethyl acetate fraction showed higher radical scavenging ability than others. Moreover, in the tyrosinase inhibition assay, showed that the ethyl acetate fraction has good inhibition effects. Results of the DPPH radical scavenging and tyrosinase inhibition activity are related with the total polyphenol concentrations of ethyl acetate fraction. In antibacterial activity used to find out by utilizing the disc diffusion assay, chloroform fraction showed strong effect against Staphylococcus aureus and S. epidermidis. These results are related with the flavonoid contents of chloroform fraction. On the other hand, in the L929 cell viability measurement by MTT assay, the hexane, butanol and aqueous fraction treated at high concentration were showed cytotoxicity. But the others samples were exhibited a moderate viabilities. As a result of investigated the antioxidant and tyrosinase inhibition activity, the ethyl acetate fraction could be applicable for cosmetics related fields. And the chloroform fraction showed significant antibacterial activity against S. aureus and S. epidermidis.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.271-279
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• 2017

This study evaluated antimicrobial efficacy and antioxidant effect of fraction isolated from Coptis Radix and confirmed its possibility as a cosmetic material. The extracts of isolated from Coptis Radix conducted an antimicrobial activity against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Candida albicans by disc diffusion method and measure clear zone. As a result, it was confirmed that antimicrobial activity against S. aureus and candida. A was observed in all samples except Fr 1. The activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and The activity of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation radical scavenging were determined by antioxidant assay according to the concentrations (50, 125, 250) ${\mu}g/mL$ of extracts of isolated from Coptis Radix. As a result, DPPH radical scavenging activity of Fr 1, 2, 3, 4 at $250{\mu}g/mL$ was 11.4%, 30.3%, 42.0% and 53.1%, respectively and $ABTS^+$ radical scavenging activity was 28.6%, 96.2%, 98.6% and 97.1% at the same concentration, respectively. Fr. 3 and 4 showed higher radical scavenging activity than the positive the control group BHT at the same concentration. In the WST assay results of measuring the cytotoxicity of Coptis Radix, except for Fr. 4, Fr. 1, 2 and 3 did not show toxicity. As a result, the fractions isolated from Coptis Radix can be regarded as a cosmetic material having antimicrobial activity and antioxidant ability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1083-1086
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• 2010

This study was conducted to investigate the inhibitory effects of daidzein against H. pylori and its cholesterol $\alpha$-glucosyltransferase ($CHL{\alpha}GcT$). $CHL{\alpha}GcT$ is responsible for the production of $\alpha$-glucosyl cholesterol which constitutes more than 25% of cell wall lipids in H. pylori, and it has been suggested that it is essential for H. pylori viability. $CHL{\alpha}GcT$ was inhibited by daidzein, in a dose-dependant manner, of which $IC_{50}$ value was $128.5\;{\mu}M$. Daidzein also showed the inhibitory effect toward H. pylori growth by paper disc diffusion assay. Therefore, it is thought that the inhibition of daidzein on $CHL{\alpha}GcT$ was related to its anti-Helicobacter activity.

• Analytical Science and Technology
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• v.30 no.3
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• pp.113-121
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• 2017

Now a day's rise of new antibiotic resistant bacterial strains is a global threat. Ethnic people of India have been employing Aphanamixis polystachya (Wall.) R. Parker wood extract in healing cancerous wounds. The aim of this study was to evaluate the antimicrobial activity and to identify the medicinally potent chemicals in the essential oil extract of A. polystachya. The antibacterial properties of various organic extracts were evaluated against a range of bacteria (gram-positive and gram-negative bacteria) based on the disc diffusion method and GC-MS based analysis for finding active oil extract components. All extracts of A. polystachya leaves showed potential antibacterial activity, notably ethyl acetate, while petroleum ether extracts revealed highly sensitive activity against all tested bacteria (zones of inhibition ranging from 8.83 to 11.23 mm). In addition, the petroleum ether extract had the lowest MIC value (32 to $256{\mu}g/mL$) against E. coli, S. lutea, X. campestris, and B. subtilis bacteria. The major compounds detected in oil [${\beta}$-elemene (16.04 %), ${\beta}$-eudesmol (12.78 %), ${\beta}$-caryophyllene (19.37 %), ${\beta}$-selinene (11.32 %), elemol (5.76 %), and ${\alpha}$-humulene (5.68 %)] are expected to be responsible for the potent antimicrobial activity. The results of this study offer valuable insights into the potent role of A. polystachya essential oil extract in pharmaceutical and antibiotic research.