• YAKHAK HOEJI
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• v.36 no.5
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• pp.407-411
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• 1992

As part of our search for less toxic antimicrobial substances from natural resources, naringin was isolated from feels of Citri fructus and then hydrolyzed to naringenin. The antimicrobial activity of naringenin was examined by measuring the minimal inhibitory concentration(MIC) against fourteen species of bacteria. The antimicrobial activity of narngenin in combination with rutin or hesperetin was evaluated by checkerboard method. Among fourteen species tested, the antimicrobial activity of naringenin was the most prominant against Staphylococcus aureus and Shigella boydii showing MIC of $100\;{\mu}g/ml$ for both species. Combinations of naringenin with rutin or hesperetin showed synergism against several species of bacteria, but no antagonism was observed.

• Journal of Ginseng Research
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• v.17 no.2
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• pp.148-152
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• 1993

One kind of microorganism was isolated and identified from Korean fresh, white and red ginseng, and the effect of a preservative, sodium benzoate on the microorganism and its thermal resistant propertues were studied. The results obtained were as follows. The predominant strain on ginseng and ginseng products was identified as Penicillium sp. The strain showed perithecium structure producing ascospores. The growth of the strain was slightly inhibited at 0.0571 concentration of sodium benzoate. The minimal inhibitory concentration (MIC) of sodium benzoate against the strain was 0.26%. The D value of the strain at 56, 59, $62^{\circ}C$ were 9.9, 5.0 and 4.5 min, respectively.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.653-658
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• 1996

As part of our search for less toxic antimicrobial agents from natural resources. rutin was isolated from Sophora japonica and then hydrolyzed to quercetin. Antimicrobial activity of quercetin was tested in vitro against five kinds of gram positive and ten kinds of gram negative bacteria by serial broth dilution method. Among fifteen kinds of bacteria tested, the antimicrobial activity of quercetin was the most potent against Proteus vulgaris showing minimal inhibitory concentration(MIC) of 125 ${\mu}$g/ml. To investigate the effect of antimicrobial combinations of quercetin with four kinds of antibiotics (ampicillin, cefazolin, oxytetracycline and chloramphenicol). the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of quercetin with four kinds of antibiotics resulted in synergism in one instance, additive effect in four instances, but no antagonism was observed.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.438-442
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• 1994

Antimicrobial activity of GL (the aqueous extract from the carpophores of Ganoderma lucidum ($F_RK_{KARST}$) was tested in vitro aginst Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration (MIC). Among fifteeen species of bacteria tested, the natimicrobial activity of GL was of antimicrobial combinations of GL with four kinds of antibiotics (ampicilin, cefazolin, oxytet-racycline and chloramphenicol), the fractional inhibitory concentraction index (FICI) was determined by checkerboard assy for each stain. The antimicrobial combinations of GL with four antibiotics resulted in additive effect in most instances, synergism in two instances, and antagonism in two instances. Synergism was obversed when GL was combined with cefazolin against Bacillus subtilis and Klebsiella oxytoca.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.693-698
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• 1992

The resistant effect of several heavy metal ions to Serratia marcescens strain P was studied by the method of minimal inhibitory concentration(MIC), and testing for their metal biosorption. S. marcescens strain P showed a good survival in the presence of high concentrations of some metal ions, namely cadmium, lead, iron, magnesium, and manganese. Copper had the most inhibitory effect among tested. The MIC value was ranged from 0.79 to 1.58 mM. Cells of S. marcescens strain P exhibit an abnormally long lag phase when incubated in high concentrations of zinc and cadmium. Pigment production was reduced by zinc and cadmium, but enhanced by lead and iron. S. marcescens strain P was resistant to ampicillin, tetracycline, cefamandole and chloramphenicol with minimal inhibitory concentration of 128 $\mu$g/ml, 32 $\mu$g/ml, 256 $\mu$g/ml, and 8 $\mu$g/ml, respectively. The kinetics study of biosorptive uptake by S. marcescens strain P revealed that 16.59% of cadmium and 35.38% of lead were eliminated from the media.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.1001-1007
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• 1994

In order to develop a natural food preservative, dried salviae miltiorrhizae radix (Salvia miltiorrhiza) was extracted with several solvents, and then antimicrobial activity was investigated. The optimum extracting condition for the antimicrobial sustance from the sample, minimal inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. Antimicrobial activity of the initial ethanol extract from the sample was the strongest compared to those of other solvent extracts such as n-hexane, acetone, butanol, methanol and water. the optimum extractingcondition for antimicrobial substance from the sample was shaking extraction for 2 hours at room temperature incase that 10 volumes of absolute ethanol was added to crushed Saliva Miltiorrhiza. The ethanol extract had strong growth inhibition activity against Gram-positive Bacteria (MIC, 3.13-50$\mu\textrm{g}$/ml) such as B. cereus, B, subtilis, L. minocytogenes, S. aureus, Sc. Mutans. Among Grampositive bacteria tested, Bacillus species was the most susceptibile to the extracted substance. The antimicrobial activity of the ethanol extract from the sample was weak to Gram -negative bacteria yeasts, for example MIC for Gram-negative bacteria and yeasts was 0.8mg/ml and 0.4-0.8mg/ml , respectively.

• Natural Product Sciences
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• v.7 no.4
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• pp.114-119
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• 2001

The effect of Rhinacanthus nasutus leaf extract on the growth of dermatophytes had been investigated. In vitro the extract exhibited high activity against various species of dermatophytes (Trichophyton mentagrophytes var. mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, Microsporum canis and M. gypseum). The minimal inhibitory concentration (MIC) values of the extract revealed that all the dermatophytes tested had MIC values of 13.6 mg/ml. The extract exhibited fungistatic activity at lower concentrations $({\leq}13.6\;mg/ml\;or\;below\;the\;MIC\;value)$ and fungicidal activity at higher concentrations $({\geq}13.6\;mg/ml$\;or\;above\;the\;MIC\;value)$. The results suggested that the extract acted on the cell wall of the dermatophytes which subsequently leading to the formation of cytopathological and membrane structural degeneration and finally leading to cell lysis and death.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.123-128
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• 2017

Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder for which no curative treatment is available. We previously reported that decreased Streptococcus salivarius and increased Acinetobacter johnsonii on the oral mucosa are associated with RAS risk. The purpose of this study was to identify antibiotics that selectively inhibit A. johnsonii but minimally inhibit oral mucosal commensals. S. salivarius KCTC 5512, S. salivarius KCTC 3960, A. johnsonii KCTC 12405, Rothia mucilaginosa KCTC 19862, and Veillonella dispar KCOM 1864 were subjected to antibiotic susceptibility test using amoxicillin, cefotaxime, gentamicin, clindamycin, and metronidazole in liquid culture. The minimal inhibitory concentration (MIC) was defined as the concentration that inhibits 90% of growth. Only gentamicin presented a higher MIC for A. johnsonii than MICs for S. salivarius and several oral mucosal commensals. Interestingly, the growth of S. salivarius increased 10~200% in the presence of sub-MIC concentrations of gentamicin, which was independent of development of resistance to gentamicin. In conclusion, gentamicin may be useful to restore RAS-associated imbalance in oral microbiota by selectively inhibiting the growth of A. johnsonii but enhancing the growth of S. salivarius.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.206-213
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• 2010

In this study, the antibacterial activities of essential oil from Zanthoxylum schinifolium against four Gram-positive bacteria and six Gram-negative bacteria were investigated. The antibacterial activity of the oils was determined using the agar-well diffusion assay, MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration). In particular, essential oil from Z. schinifolium showed higher antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria. Essential oil from Z. schinifolium displayed large inhibition zones especially against Bacillus cereus (31 mm). At concentrations between 0 and $20\;{\mu}g/mL$ the oils showed an antibacterial effect against both Gram-negative and Gram-positive bacteria. The minimum inhibitory concentration (MIC) values against nine bacteria ranged from 1.25 to $5\;{\mu}g/mL$. The minimum bactericidal concentration (MBC) values against eight bacterial ranged from 2.5 to $20\;{\mu}g/mL$, except Shigella sonnei. Furthermore, our finding on the antibacterial activities of essential oils from Zanthoxylum schinifolium validated the use of this plant for medical purposes.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.1
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• pp.34-46
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• 2012

Objectives: The object of this study was to observe the in vitro antibacterial effects of Wandae-tang extracts and combination of Wandae-tang extracts and Clindamycin against Gardnerella vaginalis ATCC14018. Methods: Antibacterial activities against Gardnerella vaginalis ATCC14018 of Wandae-tang extracts were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at minimal inhibitory concentration(MIC) and $MIC{\times}2$ levels. The combination effects of Wandae-tang extracts with Clindamycin were observed by Checkerboard microtiter assay, and the effects of bacterial growth curve was treated with Wandae-tang extracts MIC+Clindamycin MIC, 1/2 MIC and 1/4 MIC, respectively. Results: MIC of Wandae-tang extracts and Clindamycin against Gardnerella vaginalis ATCC14018 were detected as $1.719{\pm}0.856$(0.782~3.125) $mg/m{\ell}$ and $0.010{\pm}0.006$ (0.004~0.016) ${\mu}g/m{\ell}$. In addition, Clindamycin and Wandae-tang extracts were also showed marked dosage-dependent inhibition of bacterial growth, and more dramatical inhibitions were detected in Clindamycin+Wandae-tang extracts MIC treatment. Fractional inhibitory concentration index in combination of Wandae-tang extracts and Clindamycin were detected as $0.294{\pm}0.052$(0.250~0.375) at Checkerboard microtiter assay. Conclusions: The results obtained in this study suggest that Wandae-tang extracts showed antibacterial effects against Gardnerella vaginalis ATCC14018, and they also showed dosage-dependent inhibitory effects on the bacterial growth. In addition, combination treatment of Wandae-tang extracts with Clindamycin showed more synergistically potent inhibitory effects on the growth of Gardnerella vaginalis.