• 치위생과학회지
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• 제10권3호
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• pp.161-165
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• 2010

녹차의 폴리페놀류 중 수용성인 (-)-epigalocatechin을 이용하여 치주질환 원인균에 대한 항세균 작용을 조사한 결과 다음과 같은 결론을 얻었다. 1. (-)-epigalocatechin은 주요한 치주질환 원인균들인 F. nucleatum, P. intermedia 및 P. gingivalis에 대한 최소성장억제농도가 0.625 mg/ml 이하로 항균 작용이 높은 것으로 나타났다. 2. Time-kill 분석법을 실시한 결과 (-)-epigalocatechin은 F. nucleatum, P. intermedia 및 P. gingivalis에 살균작용이 있는 것으로 나타났다. 이상의 결과에서 (-)-epigalocatechin은 치주질환의 예방 및 치주 치료 후 예후를 증진시킬 수 있는 가글린 및 치약 등의 구강위생용품 개발에 이용할 수 있을 것으로 생각된다.

• Archives of Pharmacal Research
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• 제19권4호
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• pp.317-320
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• 1996

The time-kill curves of LB20304, a novel fluoroquinolone that has potent antibacterial activity against gram-positve and gram-negative bacteria, were calculated at the concentrations of 1/4-, 1/2-, 1-, 2- and 4-times the MIC against Staphylococcus aureus 77, Escherichia coli 3739E, Pseudomonas aeruginosa 1912E. The bactericidal activity of LB20304 for these strains was very rapid and comparable to that of ciprofloxacin. LB20304 produced a decrease in the $log_10$ CFU per milliliter of${\geq}$3 within 2 h at 4-times the MIC for all strains and consitently prevented regrowth of bacteria after 24 h of incubation. The MBCs (Minimal Bactericidal Concentration) of LB20304 against test organisms were equal to or at most four-times higher than the MICs.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권3호
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• pp.127-141
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• 2015

Silver-based systems activated by low intensity direct current continue to be investigated as an alternative antimicrobial for infection prophylaxis and treatment. However there has been limited research on the quantitative characterization of the antimicrobial efficacy of such systems. The objective of this study was to develop a semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model providing the quantitative relationship between the critical system parameters and the degree of antimicrobial efficacy. First, time-kill curves were experimentally established for a strain of Staphylococcus aureus in a nutrientrich fluid environment over 48 hours. Based on these curves, a modified PK/PD model was developed with two components: a growing silver-susceptible bacterial population and a depreciating bactericidal process. The test of goodness-of-fit showed that the model was robust and had good predictability ($R^2>0.7$). The model demonstrated that the current intensity was positively correlated to the initial killing rate and the bactericidal fatigue rate of the system while the anode surface area was negatively correlated to the fatigue rate. The model also allowed the determination of the effective range of these two parameters within which the system has significant antimicrobial efficacy. In conclusion, the modified PK/PD model successfully described bacterial growth and killing kinetics when the bacteria were exposed to the electrically activated silver-titanium implant system. This modeling approach as well as the model itself can also potentially contribute to the development of optimal design strategies for other similar antimicrobial systems.

• 약학회지
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• 제47권6호
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• pp.365-368
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• 2003

The bactericidal activities of DW286, a new fluoroquinolone were investigated by comparing the minimal bactericidal concentrations (MBCs) and the time-kill curve of it against some Gram-positive and Gram-negative bacterial strains. The MBCs of DW286 for the strains tested were either equal to or two-fold higher than the MICs, as were observed for the other fluoroquinolones. And DW286 exhibited rapid killing curves against the strains. Accordingly, it could be said that DW286 has bactericidal activity comparable to other fluoroquinolones.

• 치위생과학회지
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• 제11권1호
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• pp.37-40
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• 2011

Triterpenoid saponins 유도체인 OA와 UA가 치아우식증 원인균종의 하나인 Streptococcus downei의 표준균주(ATCC $33748^T$) 및 임상균주(4주)에 대하여, 액체배지희석법을 이용한 MIC값 측정 및 time-kill 분석법을 통한 살균작용 유무를 측정하여 다음과 같은 결과를 얻었다. 1. S. downei ATCC $33748^T$ 및 S. downei 임상균주(4주)들의 OA 대한 MIC 값은 $8{\mu}g/ml$로 동일하였고, UA의 대한 MIC 값은 S. downei 표준균주와 임상균주 간에 차이가 있었다. 2. Time-kill 분석법을 실시한 결과 OA와 UA는 S. downei $33748^T$에 대하여 $2{\times}MIC$ (각각 $16{\mu}g/ml$과 $8{\mu}g/ml$) 이상의 농도에서 살균작용을 갖는다는 것을 알 수 있었다. 이상의 연구결과를 종합할 때, triterpenoid saponins 유도체인 OA와 UA는 뮤탄스 연쇄상구균 중 최근에 사람의 구강 내 치면세균막에 서식하는 것으로 밝혀진 S. downei,에 대해 살균제로 작용할 수 있음을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제38권3호
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• pp.289-294
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• 2010

단삼(Salvia miltiorrhiza Bunge)은 우리나라에서 전통적으로 부종, 관절염, 간염 등과 같은 염증질환의 치료에 사용해왔다. 본 연구에서는 단삼 메탄올 추출물을 이용하여 구강미생물에 대한 항균활성을 확인하였다. 그 결과 메탄올추출물은 실험 되어진 모든 구강미생물에서 강한 항균활성을 나타내었다(MICs, 8 to $64\;{\mu}g/mL$; MBCs, 16 to $64\;{\mu}g/mL$). 추가적으로 ampicillin이나 gentamicin과의 병용투여서 최소억제농도(MIC)와 최소살균농도(MBC)가 감소하는 병용효과를 나타내었다. 더불어 메탄올추출물 단독 사용시 보다 항생제와 병용투여시 빠른 사멸효과를 보였다. 결론적으로 단삼 메탄올추출물이 치아우식을 유발하는 많은 세균들에 대한 항균효과가 뛰어남을 확인 할 수 있었으며, 안정성이 높은 천연 치아우식예방제로서의 개발가능성을 확인하였다.

• 대한수의학회지
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• 제54권3호
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• pp.189-192
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• 2014

This study evaluated the antibacterial effects of a mixture of Sophorae radix and Glycyrrhiza uralensis Fischer (1 : 1) ethanol extracts (SGE) on mice infected with Streptococcus (S.) pyogenes. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of SGE necessary for antibacterial effects against S. pyogenes were $20{\mu}g/mL$. Based on the time-kill curves for S. pyogenes, SGE was effective at $4{\times}$ MIC after 16 h. On Day 12 after challenge, the survival rate of mice treated with 2.0 mg/kg SGE was 60%. In conclusion, SGE had potent in vitro and in vivo antibacterial activities against S. pyogenes.

• International Journal of Oral Biology
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• 제36권1호
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• pp.7-11
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• 2011

Ursolic acid is a triterpenoid compound present in many plants. This study examined the antimicrobial activity of ursolic acid against mutans streptococci (MS) isolated from the Korean population. The antimicrobial activity was evaluated by the minimum inhibitory concentration (MIC) and time kill curves of MS. The cytotoxicity of ursolic acid against KB cells was tested using an MTT assay. The $MIC_{90}$ values of ursolic acid for Streptococcus mutans and Streptococcus sobrinus isolated from the Korean population were $2 {\mu}g$/ml and $4 {\mu}g$/ml, respectively. Ursolic acid had a bactericidal effect on S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at > $2 \;{\times}\; MIC (4 {\mu}g$/ml) and $4 \;{\times}\; MIC (8 {\mu}g$/ml), respectively. Ursolic acid had no cytotoxic effect on KB cells at concentrations at which it exerted antimicrobial effects. The results suggest that ursolic acid can be used in the development of oral hygiene products for the prevention of dental caries.

• International Journal of Oral Biology
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• 제35권4호
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• pp.191-195
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• 2010

Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The $MIC_{90}$ value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8 ${\mu}g/ml$. Oleanolic acid showed bactericidal effects against S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at $1\;{\times}\;MIC$ ($8{\mu}g/ml$) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.