• 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.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.742-748
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• 1994

As part of our search for less toxic antimicrobial agents from natural resources, the carpophores of Elfvingia applanata$(P_{ers}.)K_{ARST}.$ was extracted with hot water. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration(MIC). Among fourteen species of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.250 mg/ml. To investigate the effect of antimicrobial combinations of EA 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 EA with four kinds of antibiotics resulted in synergism in four instances, but no antagonism was observed. Four instances of synergism were observed when EA was combined with ampicillin against Micrococcus luteus, with cefazolin against Bacillus subtilis, with cefazolin against Micrococcus luteus and with oxytetracycline against Staphylococcus aureus.

• 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.

• Mycobiology
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• v.29 no.1
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• pp.11-14
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• 2001

A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.

• Journal of Pharmacopuncture
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• v.25 no.2
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• pp.101-105
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• 2022

Objectives: This study aims to determine the Fractional Inhibitory Concentration Index (FICI) of combinations of Melastoma malabathricum leaf fraction with ciprofloxacin or gentamicin against pathogenic bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus cereus, isolated from Diabetic Foot Ulcer (DFU) patients. Methods: We tested concentrations of 45%, 55%, 65%, and 75% of gentamicin and ciprofloxacin using dilution and agar diffusion methods. The combination of M. malabathricum leaf extract with these antibiotics was tested in vitro against all three bacteria. Results: The combination of M. malabathricum leaf extract and ciprofloxacin gave a FICI value of 0.5, indicating synergistic antibacterial activity against the test bacteria. Conclusion: The results show that the antibacterial effect of a combination of high doses of the leaf extract with either antibiotic is greater than that of the leaf extract and the antibiotics in single use.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.899-904
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• 2002

Aloe and propolis are extensively used in folk medicine. Ethanol extracts of Aloe vera (AE), ethanol extract of propolis (PE) and waxfree extract of propolis (PW) were prepared to test antimicrobial activities against five oral microorganisms (Streptococcus mutans, Enterococcus faecalis, Enteococcus hirae, Escherichia coli, Candida albicans). Antimicrobial activities were tested by serial broth dilution method and expressed by minimal inhibitory concentration (MIC). The AE showed relatively weak antimicrobial activities, while both of PE and PW greatly inhibited all microorganisms tested. To investigate the antimicrobial effects of the combined extracts of aloe with propolis, the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The combination of AE with PE or PW resulted in Synergistic effect against oral microorganisms tested (FICI=0.375) except Escherichia coli (FICI=1.0 for PE, FICI=0.75 for PW).

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.153-160
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• 1995

As part of our search for less toxic antimicrobial agents from natural resources, the antimicrobial activity of Elfvingia applanata $(P_{ers.})\;K_{arst.}$ extract was examined alone and in combination with naringenin. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against nineteen strains of bacteria and eleven strains of fungi by serial broth dilution method, and expressed by minimal inhibitory concentration (MIC). Among nineteen strains of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.125 mg/ml. EA also inhibited the growth of the selected fungi at higher concentrations ranging from 7.5 mg/ml to 15.0 mg/ml. To investigate the effect of antimicrobial combinations of EA with naringenin, the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of EA with naringenin resulted in partial synergism against Staphylococcus aureus only, and showed additive effect in two strains including Klebsiella pneumoniae and Salmonella typhi. Antagonism was not found.

• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.375-380
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• 1986

Thirty-one strains of Pseudomonas aeruginosa were submitted to the synergistic activity test of amikacin(AK) and gentamicin(GM) combined with moxalactam(MX), ceftizoxime(CTZ) or cefoperazone(CFZ). The minimal inhibitory concentrations(MICs) of each drug and drugs combined in various ratios were measured by checkerboard dilution method. The synergism was determined through analysing the MIC distribution curve on isobologram and calculating the fractional inhibitory concentration index(FICI). MICs of GM, AK, MX, CFZ and CTZ against the 31 tested strains were distributed from $12.5{\mu}g/ml$ to $800{\mu}g/ml$, from $0.8{\mu}g/ml$ to $25{\mu}g/ml$, from $3.1{\mu}g/ml$ to $50{\mu}g/ml$, from $3.1{\mu}g/ml$ to $400{\mu}g/ml$, and from $12.5{\mu}g/ml$ to $100{\mu}g/ml$, respectively. The rate synergism of each drug combination by means of FICl was 45.5% in GM-MX, 36.4% in GM-CFZ, 63.6% in GM-CTZ, 48.6% in AK-MX, 35.3% in AK-CFZ, and 35.7% in AK-CTZ combination. Thus, it is suggested that Pseudomonas aeruginosa may effectively be inhibited by various aminoglycoside and cephalosporin combinations.

• 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.

• The Korea Journal of Herbology
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• v.30 no.5
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• pp.15-21
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• 2015

Objectives : Methicillin-resistantStaphylococcus aureus(MRSA) is a human pathogen. New antibacterial agents are needed to treat MRSA-related infections. This study investigated the antibacterial activity of EtOH 70% extracts ofTonghyeonipal-dan(THD) which prescription is composed of oriental medicine against MRSA.Methods : The antibacterial activity of THD was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method, Checkerboard dilution test, and Time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors were used.Results : The minimum inhibitory concentration (MIC) of THD is 1,000~2,000 μg/mL against MRSA. In the checkerboard dilution test, fractional inhibitory concentration index (FICI) of THD in combination with antibiotics indicated synergy or partial synergism againstS. aureus. Furthermore, a time-kill assay showed that the growth of the tasted bacteria was considerably inhibited after 24 h of treatment with the combination of THD with selected antibiotics. For measurement of cell membrane permeability, THD 500 μg/mL along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (TRIS) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide (NaN3) were used as an inhibitor of ATPase. TX, TRIS, DCCD and NaN3 cooperation againstS. aureusshowed synergistic action.Conclusions : Accordingly, antimicrobial activity of THD was affected by cell membrane and inhibitor of ATPase were assessed. These results suggest that THD has antibacterial activity, and that THD extract offers great potential as a natural antibiotic against MRSA.