• The Journal of Internal Korean Medicine
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• v.34 no.3
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• pp.278-288
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• 2013

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) has a cephalosporin and beta-lactam antibiotic-resistant strains. MRSA is one of the major pathogens causing hospital infection and the isolation ratio of MRSA has gradually increased. Consequently, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. Methods : The antibacterial activities of Ipyo-san were evaluated against 2 strains of MRSA and 1 standard Methicillin-susceptible staphylococcus aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MIC) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay performed under dark. Results : The MIC of Ipyo-san water extract against S. aureus strains ranged from 1000 to $2,000{\mu}g/ml$, so we confirmed that it had a strong antibacterial effect. Also, the combinations of Ipyo-san water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Ipyo-san water extract against MRSA has antibacterial activity so it has potential as alternatives to antibiotic agents. For the combination test, we used Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of Ipyo-san water extract was affected by the cell membrane. Conclusions : We suggest that the Ipyo-san water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Journal of fish pathology
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• v.22 no.1
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• pp.1-7
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• 2009

To investigate the effect of hydrogen peroxide in israel carp, Cyprinus carpio, toxicity and microbial activities were determined. For hydrogen peroxide toxicity test, the median lethal concentration ($LC_{50}$) to israel carps Cyprinus carpio (average weight 0.44 g) by acute toxicity was determined after 24 hour treatment. All israel carp were alive in 24 hours treatment at 80 $\mu\ell/\ell$ concentration and $LC_{50}$ value was 148.9 $\mu\ell/\ell$. For biocidal activities of hydrogen peroxide, remove of parasite and growth inhibition of pathogenic bacteria were determined. The parasite Trichodina sp. infected on the skin and gills of israel carps (average weight 0.1 g) was completely eliminated at 40 $\mu\ell/\ell$ of hydrogen peroxide treatment for 24 hour. Most of the minimum inhibitory concentrations (MICs) against 30 fish pathogenic bacteria were less than 40 $\mu\ell/\ell$.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.872-881
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• 2012

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 $log_{10}$, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GC-MS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.155-161
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• 2021

This study was attempted to investigate natural materials with antimicrobial activity and to apply as natural preservatives in cosmetics. The disc diffusion method was used to search for nine species of natural antibacterial material for three species of skin pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) and Candida albicans. As a result of measuring the size of inhibition zone, Rhus Semialata gall (Gallnut) extract, Oak vinegar, and ε-polylysine were showed strongest antibacterial activities (> 10 mm). The Minimum Bactericidal Concentration (MBC) of gallnut and oak vinegar ranged from 10 to 20 mg/mL and from 20 to 40 mg/mL against five human skin pathogens. The MBC of ε-polylysine ranged from 0.5 to 2 mg/mL in fungus. The synergic effect of gallnut extract/oak vinegar mixture and gallnut extract/ε-polylysine mixture were evaluated by checkerboard test. Compared to when used alone, the MBC of gallnut extract/oak vinegar mixture were at 4 times lower concentration against E. coli, C. albicans, and A. brasiliensis. Also Furthermore, the MBC of gallnut extract/ε-polylysine mixture were at 4 times lower concentration against C. albicans and A. brasiliensis. It was confirmed that the combination of gallnut extract with oak vinegar or ε-polylysine resulted in synergistic antibacterial effect against three human skin pathogens. Thus, it is expected that gallnut extract and natural product mixture can not only demonstrate antibacterial synergies, but also be applied in cosmetics as a natural preservative system with a wide antibacterial spectrum.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.774-783
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• 2001

The ethanol extract of 77 species of edible and medicinal plants were examined antimicrobial activity against 5 strains of Listeria monocytogenes ATCC 19111, ATCC 19112, ATCC 19113, ATCC 19114 and ATCC 15313 by optical density using Bioscreen C. The ethanol extract of Siegesbeckia glabrescens Makino, Jeffersonia dubia Benth, Aquilaria agallocha Roxburgh, Lysimachia clethroides Duby and Nardostachys chinensis Batal. exhibited comparatively strong growth inhibition effect on 5 strains of L. monocytogenes at 1000 ppm level in broth. The minimum inhibitory concentration (MIC) of ethanol extract of Lysimachia clethroides Duby was $100{\sim}500\;ppm$ on 5 strains of L. monocytogenes. The MIC of the n-hexane and chloroform fraction of the extract were same concentration as $50{\sim}100\;ppm$. The n-hexane fraction of Lysimachia clethroides Duby showed strong growth inhibition at 25 ppm on Vibrio parahaemolyticus for 72 hr at $30^{\circ}C$ and at 50 ppm on Bacillus cereus and at 500 ppm on Staphylococcus aureus and Escherichia coli.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.816-822
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• 2006

The antimicrobial and antioxidative effect of mechanical bamboo smoke distillate (MBSD) and traditional bamboo smoke distillate (TBSD) were investigated. Antimicrobial activity was demonstrated against all the microorganisms used in this experiment and was the higher in TBSD than in MBSD, with an activity concentration in the range 10-50 ${\mu}m/8$ mm paper disc. At the same concentration the antimicrobial activities of TBSD and MBSD was Gram positive bacteria>gram negative bacteria>Lactotobacillus>yeast. The minimum inhibition concentration (MIC) of BSC was 1.0-7.3${\mu}L/mL$, and the maximum lethal concentration (MLC) was 26.7-116.7 ${\mu}L/mL$. The soybean oil oxidative stability increased with increasing BSD concentration. The induction periods of oil oxidation were 3.75, 4.57 and 12.06 days for the samples with BSD added at 0.1%, 0.5%, and 1.0%, respectively. The RAE in soybean oil with 0.5% BSD was evaluated to be 168.45%, being similar to that of the sample with 0.02% BHT.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1763-1772
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• 2017

This study aimed to isolate and characterize antibacterial metabolites from Pharbitis nil seeds and investigate their antibacterial activity against various plant pathogenic bacteria. The methanol extract of P. nil seeds showed the strongest activity against Xanthomonas arboricola pv. pruni (Xap) with a minimum inhibition concentration (MIC) value of $250{\mu}g/ml$. Among the three solvent layers obtained from the methanol extract of P. nil seeds, only the butanol layer displayed the activity with an MIC value of $125{\mu}g/ml$ against Xap. An antibacterial fraction was obtained from P. nil seeds by repeated column chromatography and identified as pharbitin, a crude resin glycoside, by instrumental analysis. The antibacterial activity of pharbitin was tested in vitro against 14 phytopathogenic bacteria, and it was found to inhibit Ralstonia solanacearum and four Xanthomonas species. The minimum inhibitory concentration values against the five bacteria were $125-500{\mu}g/ml$ for the n-butanol layer and $31.25-125{\mu}g/ml$ for pharbitin. In a detached peach leaf assay, it effectively suppressed the development of bacterial leaf spot, with a control value of 87.5% at $500{\mu}g/ml$. In addition, pharbitin strongly reduced the development of bacterial wilt on tomato seedlings by 97.4% at $250{\mu}g/ml$, 7 days after inoculation. These findings suggest that the crude extract of P. nil seeds can be used as an alternative biopesticide for the control of plant diseases caused by R. solanacearum and Xanthomonas spp. This is the first report on the antibacterial activity of pharbitin against phytopathogenic bacteria.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.984-993
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• 1999

The ethanol extracts and its n-hexane fraction of Dystaenia takesimana Kitagawa exhibited growth inhibition on Listeria monocytogenes ATCC 19111, ATCC 19112, ATCC 19113, ATCC 19114 and ATCC 15313. The minimum inhibitory concentration of the ethanol extract and its n-hexane fraction were 50 ppm and below 30 ppm on Listeria monocytogenes respectively. By silica gel column chromatography, the active fraction A8 was obtained from the ethanol extract of Dystaenia takesimana Kitagawa. After three times of column chromatography, the SBD-1 and SBD-2 were separated from the A8 fraction of the ethanol extract of Dystaenia takesimana Kitagawa. Antimicrobial activity of the SBD-l and SBD-2 was lower than that of the A8. And the A8 exhibited growth inhibition on five strains of Listeria monocytogenes at the level of $10{\sim}30$ ppm and the bactericidal effect was confirmed at same the level. The purified antimicrobial active compound was identified as (9z)-heptadeca-l,9-dien-4,6-diyn-3,8-diol, falcarindiol, by EI/MS, $^{1}H-NMR$ and $^{13}C-NMR$.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1182-1187
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• 2003

This study was performed to evaluate the potentiality of Reynoutria elliptica Migo., being used as a folk remedy and a herb medicine for urethritis, cystitis, etc., on growth inhibition of Helicobacter pylori which is known as the ulcerogenic pathogen. The minimum inhibitory concentration (MIC) value of methanol extract from Reynoutria elliptica Migo, was determined to be 120 ppm for H. pylori and urease activity derived from H. pylori was inhibited over 80% by the extract at 2 mg/mL in urea broth. Among various solvent fraction of the methanol extract, the hexane fraction showed a significant inhibitory effect on the growth of H. pylori reducing both its growth and urease activity. Scanning and transmission electron micrographs of H. pylori treated with the methanol extract at 2 mg/mL for 3 hr showed that the cell walls and membranes were disrupted so that the cytoplasmic components were leaked from the body. These results suggest that Reynoutria elliptica Migo. possesses a therapeutic potential on the gastric disease caused by H. pylori.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.367-373
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• 2008

The natural products are used to be development of new antibacterial substances against human pathogenic bacteria. Adherence to the tooth surface by S. mutans is an important step in initiation of dental caries. This study was to examine antibacterial activity and anti-adhesive effect of Scutellaria baicalensis extract against S. mutans. Extracts of S. baicalensis were tested for antimicrobial activities by paper disc methods and radial diffusion assay methods, and bacterial adherence assay using 3 type of hydroxyapatite. The antibacterial level of ethyl acetate extract, IPK-3 on the growth of S. mutans was 125 mg/ml of minimum inhibitory concentration (MIC). The maximum growth of S. mutans in medium added with IPK-3 extract (50 mg/ml) was delayed to 30 hr, while the highest at 24 hr in control medium. The pH values of the control medium was 5.63 at 18 hr, but the media supplemented with IPK-3 extract was pH 6.50 at 12 hr. In adhesive inhibition assay, S. mutans was labelled with the fluorescent indicator DAPI and measured with fluorescence microscope. Adhesion of S. mutans on hydroxyapatite beads was inhibited by IPK-3 extracts. These results suggest that S. baicalensis extract can be used as an effective material for antibacterial activity and adhesive inhibition against S. mutans.