• The Korea Journal of Herbology
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• v.35 no.3
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• pp.47-54
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• 2020

Objective : Infectious diseases are a growing problem worldwide by Methicillin-resistant Staphylococcus aureus (MRSA). Daehwangmokdan-tang is one of the oriental medicine prescriptions contained in Principles and Practice of Eastern Medicine. This study investigated the antibacterial activity of EtOH 70% extracts of Daehwangmokdan-tang (DMT) which prescription is composed of oriental medicine against MRSA. Methods : The antimicrobial activity and active concentration of MRSA were verified by measuring the minimum inhibitory concentration (MIC) of DMT. In addition, the effects of the disease were checked by treating the existing antibiotics and large ethanol extract in parallel, and the extent of growth suppression was checked over time. In addition, cell membrane permeability experiment confirmed the effect of large DMT on the immunity mechanism of MRSA. Results : TThe minimum inhibitory concentration of DMT against MRSA is 500 ~ 2000 ㎍/㎖ by broth dilution method. In the checkerboard method, the combinations of DMT with antibiotics has partial synergistic effect or synergy effect and DMT markedly reduced the MICs of the antibiotics oxacillin (OX), gentamicin (GEN) against MRSA. In the inhibition of resistance mechanism of DMT against MRSA, the expression of resistance gene and protein about β-lactam antibiotic was reduced. Also, we observed the effect of DMT about cell membrane permeability against MRSA, and confirmed that DMT suppressed growth of strains by increasing cell membrane permeability and energy metabolism. Conclusion : Basis on the result, we speculate that DMT may be useful for the treatment of MRSA infections when used in combination with β-lactam antibiotic.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.1
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• pp.100-107
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• 2009

Objective : The purpose of this study is to investigate the antibacterial activity of Saussurea lappa for the applications of herb-based extracts to both cosmetic and medicinal industries. Methods : Antibacterial activity of ethanol extract of Saussutes lappa (ESL) was assessed using agar diffusion and broth dilution methods, and determined by whether clear zone was formed around paper disc and in terms of the size (mm) of clear zone, Results : ESL provided activity against Staphylococcus aureus KCTC 1927 in concentration of 1 mg/ml with an clear zone of 16 mm, and showed an activity against Staphylococcus epidermids KCTC 1917 in concentration of 1 mg/ml with an clear zone of 18mm. Moreover, the minimum inhibitory concentration (MIC) of ESL against S. sureus and S. epidermidls were 1 mg/ml for both bacterial species. However, ESL showed no growth inhibition against Pseudomonas aeruginosa KCTC 12513, Enterobactet aerogenes KCTC 2190, Escherichia coli KCTC 2571, Salmonella typhimurium KCTC 1925 and Propionibacterium acnes KCCM 41747. Conclusions : Antibacterial activity of ESL against Staphylococcus sureus and Staphylococcus epidermids causing eye and skin diseases was proved. The result suggest that ESL may be useful as a natural preservative on behalf of synthetic preservatives.

• International Journal of Oral Biology
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• v.44 no.4
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• pp.152-159
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• 2019

The oral care probiotic strain Weissella cibaria CMU (oraCMU) inhibits volatile sulphur compounds associated with halitosis, presumably by inhibiting the growth of associated oral pathogens. In the present study, we investigated whether oraCMU inhibits the production of these compounds by suppressing the expression of mgl. This gene encodes L-methionine-α-deamino-γ-mercaptomethane-lyase (METase) and is involved in the production of methyl mercaptan (CH₃SH) by Porphyromonas gingivalis. Therefore, we specifically investigated the effects of oraCMU on the growth, CH₃SH production, METase activity, and mgl expression of P. gingivalis. The minimum inhibitory concentrations of cell-free supernatant and secreted proteins from oraCMU were 125 mg/mL and 800 ㎍/mL, respectively. At sub-minimum inhibitory concentration levels, these metabolites inhibited CH₃SH production, but they also reduced P. gingivalis viability. Only heat-killed oraCMU decreased CH₃SH production without affecting P. gingivalis viability. Heat-killed oraCMU also inhibited METase activity toward L-methionine and mgl mRNA expression (p < 0.05). In summary, we demonstrated the inhibition of volatile sulphur compounds via the antimicrobial action of oraCMU and, for the first time, the inhibition of such compounds by heat-killed oraCMU, which occurred at the molecular level.

• Korean Journal of Pharmacognosy
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• v.49 no.3
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• pp.255-261
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• 2018

The aim of this study was to evaluate the anti-helicobacter activity and anti-inflammatory activity of Angelica dahurica (AD). The minimum inhibitory concentration(MIC) of AD against Helicobacter pylori(H. pylori), expression of the H. pylori cagA gene in the presence of AD was determined. Inhibition of H. pylori urease by AD, inhibition of nitric oxide (NO) production in AGS cells was measured. IL-8 mRNA expression in AGS cells which were infected with H. pylori and IL-8 level was measured. The MIC of MeOH Ex. of AD was $250{\mu}g/mL$ and the expression of cagA gene was decreased about 88% in the presence of AD. The activity of H. pylori urease was inhibited 70% by AD. mRNA expression of IL-8 and the production of NO and IL-8 were significantly decreased in the presence of AD. In conclusion, AD showed anti-Helicobacter activity and has potent anti-inflammatory effect on H. pylori-induced inflammation in human gastric epithelial AGS cells.

• Natural Product Sciences
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• v.23 no.1
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• pp.46-52
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• 2017

The aim of this study was to evaluate the anti-Helicobacter pylori activity of fractions and major aglycon compounds (baicalein, chrysin, oroxylin A, wogonin) of Scutellariae Radix. Minimum inhibitory concentration (MIC) measurement, DPPH radical-scavenging assay, DNA protection assay, and urease inhibition analysis were performed. The ethyl acetate (EtOAc) fraction showed the potent anti-Helicobacter activity, and therefore, compounds in the EtOAc fraction were subjected to further assay. The MICs of chrysin, oroxylin A, and wogonin against Helicobacter pylori 26695 were 6.25, 12.5 and $25{\mu}g/mL$, respectively. Baicalein exhibited the most effective DPPH radical-scavenging activity. DNA protection using Fenton reaction, chrysin, oroxylin A, and wogonin showed effective DNA protective effect. This result was also confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Regarding Jack bean urease (0.5 mg/mL, 50 unit/mg) inhibition, 20 mM ofbaicalein and chrysin inhibited urease activity by 88.2% and 72.5%, respectively.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.65-70
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• 2010

Objectives : Biological activities of marine resources have been rarely evaluated compared with other herbal medicines. In the present study, we aimed to evaluate antimicrobial activities of aqueous and ethanolic extracts of five marine resources(Porphyra tenera, Laminariae Thallus, Sargassum, Ostreae Concha, Maliotidis Concha) against Propionibacterium acnes. Methods : Aqueous axtracts of five marine resources were prepared by decocting in tenfold tap water for 3 h. Etanolic extracts were obtained by extracting five marine resources with tenfold ethanol for 72 h at room temperature. The zone of growth inhibition and minimum inhibitory concentration (MIC) were determined against P. acnes after incubation for 48 h under anaerobic condition. Results : Ethanolic extracts of Porphyra tenera exhibited potent antimicrobial effects(MIC $62.5\;{\mu}g/m{\ell}$ against KCTC3320, MIC $31.25\;{\mu}g/m{\ell}$ against KCTC5527). However, all aqueous extracts tested had no effects on the growth inhibition of P. acnes. In addition, four ethanolic extracts except Porphyra tenera showed little inhibitory effect. Conclusions : These results indicate that ethanolic extracts of Porphyra tenera has antimicrobial activities against P. acnes and also warrant further development of Porphyra tenera extracts as a natural anti-acne agent.

• Journal of Life Science
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• v.30 no.3
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• pp.278-284
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• 2020

Magnolia kobus is known to exert various biological effects, such as antioxidant and hypnotic activity. In this study, we investigated the antimicrobial and anti-inflammatory activity of M. kobus essential oil extracted using steam distillation. Its antimicrobial activity was tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by the paper disk diffusion and minimum inhibitory concentration (MIC) methods. Its anti-inflammatory activity was evaluated by measuring its inhibition ratio on the production of nitric oxide (NO) and PGE₂ in lipopolysaccharide (LPS)-induced RAW264.7 cells. Its composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that M. kobus essential oil exhibited excellent antibacterial activity against S. aureus, with a clear zone of 18 mm and an MIC value of 0.25 mg/ml. Its clear zones against P. aeruginosa and E. coli were 14 mm and 17 mm, respectively, while its MIC values were 1 mg/ml and 0.5 mg/ml, respectively. The essential oil exhibited no cytotoxicity to the RAW264.7 cells at a concentration of 500 ㎍/ml while showing NO (37.7%) and PGE₂ inhibition (24.0%). Its three main fragrance ingredients identified were 3-carene (77.07%), β-elemene (6.92%), and caryphyllene (2.86%). The results suggest that M. kobus essential oil has potential as a cosmetic functional material with antimicrobial and anti-inflammatory effects.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.226-236
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• 2020

Antibiotic resistance by pathogenic bacteria and fungi is one of the most serious global public health problems in the 21^st century, directly affecting human health and lifestyle. Pseudomonas aeruginosa and Staphylococcus aureus with strong resistance to the common antibiotics have been isolated from Intensive Care Unit patients at Zagazig Hospital. Thus, in this study we assessed the biocidal activity of nanoparticles of silver, copper and zinc synthesized by Fusarium solani KJ 623702 against these multidrug resistant-bacteria. The synthesized Metal Nano-particles (MNPs) were characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Zeta potential. The Fourier transform infrared spectroscopy (FTIR) result showed the presence of different functional groups such as carboxyl, amino and thiol, ester and peptide bonds in addition to glycosidic bonds that might stabilize the dispersity of MNPs from aggregation. The antimicrobial potential of MNPs by F. solani against the multidrug-resistant (MDR) P. aeruginosa and S. aureus in addition to the mycotoxigenic Aspergillus awamori, A. fumigatus and F. oxysporum was investigated, based on the visual growth by diameter of inhibition zone. Among the synthesized MNPs, the spherical AgNPs (13.70 nm) displayed significant effect against P. aeruginosa (Zone of Inhibition 22.4 mm and Minimum Inhibitory Concentration 21.33 ㎍/ml), while ZINC oxide Nano-Particles were the most effective against F. oxysporum (ZOI, 18.5 mm and MIC 24.7 ㎍/ml). Transmission Electron Microscope micrographs of AgNP-treated P. aeruginosa showed cracks and pits in the cell wall, with internalization of NPs. Production of pyocyanin pigment was significantly inhibited by AgNPs in a concentration-dependent manner, and at 5-20 ㎍ of AgNPs/ml, the pigment production was reduced by about 15-100%, respectively.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.465-474
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• 2014

This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an $IC_{50}$ value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with ${\geq}2.5 $ MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HD-Cinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.488-496
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• 2021

In this study, a study was conducted to utilize Orostachys japonica A. Berger EtOAc fraction extract as an antibacterial activity and cosmetic ingredient. As a result of measuring the antimicrobial activity of Orostachys japonica A. Berger EtOAc, the growth of S. aureus, S. epidermidis, and P. aeruginosa was inhibited. Among them, S. aureus was an extract of 18.35 ± 1.5 mm Orostachys japonica A. Berger EtOAc fraction at a concentration of 0.5 g / mL, showing superior antibacterial activity than methyl paraben (16.83 ± 1.0 mm), and was shown as a positive control. As a result of evaluating the MIC of the Orostachys japonica A. Berger EtOAc fraction extract through MIC measurement, the remaining strains excluding Candida. A showed a MIC of 17.5 mg/mL. As a result of evaluating the cosmetic preservation effect through the challenge test applied to the cosmetic emulsion formulation, the growth inhibitory effect of S. aureus in the emulsion containing 0.3% Orostachys japonica A. Berger EtOAc fraction extract 7 days after microbial inoculation was 100%.