• Mycobiology
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• v.31 no.4
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• pp.248-250
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• 2003

Kojic acid was investigated for its antifungal activity against the human pathogenic fungi including Candida albicans, Cryptococcus neoformans and Trichophyton rubrum. For C. albicans, C. neoformans and T. rubrum, the MIC(minimum inhibitory concentration) of kojic acid was 640, 80 and 160 ${\mu}g/ml$, respectively. In C. neoformans, melanin-producing yeast, kojic acid-treated nonmelanized cell was more susceptible to magainin than melanized cell, suggesting melanin give a protective function against microbial peptide.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.125-133
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• 2023

Purpose : This study aimed to analyze the antibacterial activity of Liriope platyphylla ethanol extract (LPEE) against Streptococcus mutans and Porphyromonas gingivalis and to validate its potential for the prevention and treatment of dental caries, gingivitis, and periodontal disease. Methods : To verify the antibacterial effect of L. pulsatilla ethanolic extract (LPEE) against S. mutans and P. gingivalis, the disk diffusion method was used to determine the inhibition zones at concentrations of 50, 100, 200, and 300 mg/㎖. To determine the minimum inhibition concentration (MIC), the final dose of LPEE was .2, .4, .8, 1.6, 2.5, and 5.0 mg/㎖, and the minimum bactericidal concentration (MBC) was determined based on the MIC results. To confirm the growth inhibitory effect of LPEE on both pathogens, the absorbance was measured at 600 nm after each incubation for 0, 3, 6, 12, and 24 hr at concentrations of .8, 1.6, 2.5, and 5.0 mg/㎖. Results : The cytotoxicity of LPEE was evaluated and the cell viability was more than 70 % at 400 mg/㎖. Therefore, concentrations of 50, 100, 200, and 300 mg/㎖ were used in this study. The antimicrobial effect against S. mutans was seen at 100 mg/㎖ and grew in a concentration-dependent manner, while P. gingivalis was effective at 50 mg/㎖ with the dose dependency. The MIC was .8 mg/㎖ for both strains, and the MBC was 1.6 mg/㎖ with the same results. The growth inhibitory effect of LPEE on S. mutans and P. gingivalis was observed, even at low concentrations. Conclusion : The antibacterial effect of LPEE was evaluated through the analysis of MIC, MBC, and growth inhibition effect on S. mutans and P. gingivalis, which suggests LPEE might have the possibility of utilization as a preventive and therapeutic composition for oral diseases.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.853-858
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• 2003

Helicobacter pylori specifically adhere to host cells through a number of putative receptors and ligands, mainly based on carbohydrate-protein interactions. Polysaccharide fractions isolated from the leaves of Artemisia capillaris showed different inhibitory activities against H. pylori adhesion by using hemagglutination assay. Among these fractions, an acidic polysaccharide fraction FlA showed highly effective inhibitory activity, and its minimum inhibition concentration was 0.63 mg/ml. The inhibition results by the hemagglutination assay were consistent with those obtained by the enzymelinked glycosorbent assay, which was developed by the conjugation of horseradish peroxidase with fetuin, a sialic acid-containing glycoprotein which was specific to H. pylori adhesion. FlA contained the highest carbohydrate content among polysaccharide fractions, and no protein was detectable when further purified by gel filtration FPLC. Sugar composition analysis using GC revealed the highest amount of galacturonic acid among sugars, which suggests that FlA contains essentially acidic polysaccharides. Our data suggest that acidic polysaccharides may play an important role in the inhibition of H. pylori adhesion to host cells.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.435-439
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• 2019

An efficient one pot multicomponent synthesis of pyrimidinone derivatives of Biginelli type is described. 4-amino-6-aryl-pyrimidine-5-carbonitrile molecules were synthesized efficiently via three-component Biginelli-type condensation of aldehyde, malononitrile, and semicarbazone as urea substituent in the presence of a catalytic amount of PEG-400 as green medium under microwave irradiation. The reactions proceeded efficiently in the presence of microwave radiation to afford the desired products in good to excellent yields. Products have been confirmed by IR, and NMR spectral analysis. All the molecules were tested for their antimicrobial activity against E. coli, S. aureus, P. aeruginosa and C. tropicalis. Some of the compounds have shown moderate to good inhibition efficiency against both gram-positive and gram-negative bacteria. The potent activity was observed against the fungal species with minimum inhibition concentration 12.5 ㎍/mL.

• 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.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.145-152
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• 2020

In this study, the antimicrobial activity was tested by Ethanol extract(ET), Ethyl acetate fraction(EA) and Butanol fraction(BT) of Rhus javanica L fruit as natural preservatives. The antimicrobial activity were tested by Paper disc method and minimum inhibitory concentration (MIC) for microorganisms (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida Albicans). As a result of the antimicrobial activities of P. aeruginosa fruit extracts have shown the clear zone that S. aureus, S. epidermidis, E. coli, and P. aeruginosa. In BT, additional clear zones were observed for the Candida. The MIC results showed that EA samples showed the lowest concentrations for S. aureus S. epidermidis, E. coli, and P. aeruginosa. Accordingly, it can be concluded that these Rhus javanica L fruit extracts have the potential for antimicrobial materials for the cosmetic industry.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.418-421
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• 2000

A new direct colorimetric assay of microcystin in water and algal samples is proposed consisting of two procedures as follows: 1) the elimination of phosphorus in the sample and concentration of microcystin using a C(sub)18 cartridge, 2) the detection of the released phosphorus by the ascorbic acid method and determination of protein phosphatase (PP) inhibition by microcystin. The optimum amounts of phosphorylase ${\alpha}$ and PP-1 in 50 ${\mu}$L concentrated sample were 50$\mu\textrm{g}$/50${\mu}$L buffer and 1.0unit/50${\mu}$L buffer, respectively, for the best assay. The pH for the maximum activity of PP-1 was 8. The minimum detectable concentration for this method was about 0.02$\mu\textrm{g}$/L, which is sufficient to meet the proposed guideline level of 1$\mu\textrm{g}$ microcystin/L in drinking water. Consequently, it would seem that the proposed direct colorimetric assay using PP is a rapid, easy, and convenient method for the detection of microcystin in water and algal samples.

• Natural Product Sciences
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• v.23 no.3
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• pp.175-182
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• 2017

This study evaluated the anti-Helicobacter and anti-inflammatory effects of Sohamhyungtang (SHHT). The minimum inhibitory concentration (MIC) of SHHT against Helicobacter pylori (H. pylori) was determined by the agar dilution method. Expression of the H. pylori cagA gene in the presence of SHHT was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Inhibition of H. pylori urease by SHHT was determined by the phenol-hypochlorite assay. Antiadhesion activity of SHHT was measured by urea-phenol red reagent. Inhibition of nitric oxide (NO) production in AGS cells was measured with Griess reagent. Inducible nitric oxide synthase (iNOS) and IL-8 mRNA expression in AGS cells which were infected with H. pylori was determined by qRT-PCR. IL-8 level was measured by enzyme-linked immunosorbent assay (ELISA). The MIC of SHHT was $100{\mu}g/mL$ and the expression of cagA gene was decreased about 25 folds in the presence of SHHT. H. pylori urease was inhibited 90% by SHHT. SHHT inhibited H. pylori adhesion on AGS cell in a concentration dependent manner. mRNA expression of iNOS and IL-8 and the production of NO and IL-8 were significantly decreased in the presence of SHHT. In conclusion, SHHT showed anti-Helicobacter activity and has potent anti-inflammatory effect on H. pylori-induced inflammation in human gastric epithelial AGS cells.

• Biomedical Science Letters
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• v.27 no.4
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• pp.264-269
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• 2021

The purpose of this study was to evaluate the disinfecting efficacy of peracetic acid (PAA), sodium hypochlorite (NaOCl) and phenol, which are representative disinfectants in medical environments using four types of multi-drug resistance (MDR) clinical isolates with healthcare-associated infections (HAI). 26 antibiotic susceptibility tests were conducted for the four types of MDR clinical isolates in the same way as for clinical specimens. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the disinfectants were determined by using in vitro liquid medium dilution method and inoculation of the plate medium. Both the MIC and MBC of phenol against MRSA and VRE were 3.1%, while those against KPC and MRPA were 6.2%. The MIC and MBC of peracetic acid (PAA) against MRSA, VRE, KPC, and MRPA were 0.18%. The MIC and MBC of sodium hypochlorite (NaOCl) against MRSA were 0.39% and 0.78%, respectively. Both values of MIC and MBC were 0.78% for VRE. In addition, KPC and MRPA showed 0.39% for MIC and 0.78% for MBC. For all MDR strains used in this study, sodium hypochlorite and peracetic acid showed significant sterilizing efficiency, while no clear correlation was identified between antibiotic resistance clinical isolated and ability of disinfection.

• Journal of Food Hygiene and Safety
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• v.10 no.3
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• pp.139-145
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• 1995

In order to develop a natural food preservative, the root bark of Morus alba was extracted with several solvents, and then antimicrobial activity was investigated. The optimum extracting condition for the antimicrobial substance from the sample, minimum inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. The antimicrobial activity of the ethanol extract form the sample was stronger than those of the extracts by the other solvents such as water, methanol. ethyl acetate and acetone. The optimum extracting condition for antimicrobial substance from the sample was shaking extraction twice for 5 hours at room temperature in case of 7 times of absolute ethanol added to the crushed root bark of Morus alba. The ethanol extract from the root bark of Morus alba had strong B. cereus, L. monocytogenes and S. aureus. Especially, Bacillus species was the most susceptible to the extracted substance. The ethanol extract showed antimicrobial activity against Gram negative bacteria(MIC, 160~1600 ug/ml) and yeasts(MIC, 1600 ug/ml) such as C. albicans and S. acidifaeciens. The extract also showed growth inhibition against molds such as A. niger, A. parasiticus, A versicolar and T. viride.