The present study is designed to investigate the antibacterial effect of the hot-water and various ethanol extracts from the leaves of Dendropanax morbifera L. (DML) against Porphyromonas gingivalis (P. gingivalsis). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 30, 50 and 70% ethanol extract of DML against P. gingivalis decreased in a concentration-dependent manner. However, MIC and MBC of hot-water and 30% ethanol extract against P. gingivalis were the same as 3.13 and 6.25 mg/mL, respectively. In the bacterial growth inhibition test, the growth of P. gingivalis in the group treated with MBC and 2×MBC of DML hot-water extract was statistically significantly decreased from 6 h after incubation compared to the control group (p<0.001). From the results portrayed above, aqueous extract from DML at the concentration of 6.25 mg/mL can be usefully used to suppress infection of P. gingivalis, a major causative agent of periodontal disease.

목적: 본 연구는 안경수건에 함유된 은나노 입자의 항균효과를 연구하기 위해 수행되었다. 방법: 은나노 입자가 함유된 안경수건과 함유되지 않은 안경수건의 세균수를 비교하였다. 결과: 은나노입자가 함유된 안경수건에서 뚜렷한 세균수의 감소가 관찰되었으며, 이 결과는 안경렌즈에 존재하는 세균에 대해 은나노 입자가 높은 항균성을 가짐을 의미한다. 결론: 가까운 미래에 나노기술을 이용한 항균작용 안경수건의 개발이 기대된다.

In this study, we investigated the effects of indole on biofilm formation inhibition in Pantoea agglomerans (P. agglomerans). In the biofilm growth assay, indole inhibited biofilm formation across all the growth time. Depending on biofilm growth stage, indole exhibited biofilm inhibition and anti-bacterial effects on planktonic cells. Through the analysis of the proportion rate between biofilm and Colony Forming Units (CFU) and inhibition rate of indole, we confirmed that depending on the biofilm stage of P. agglomerans, indole treatment timing was more important than the treatment duration. By comparing gene expression rates through rt-qPCR P.agglomerans affected by indole was found to significantly change quorum sensing (pagI/R) and indole transportation (bssS) gene expressions. Throughout all, indole exhibited both antimicrobial and anti-biofilm effects on P. agglomerans. In addition, we confirmed the anti-biofilm effects of indole on mature biofilm. In conclusion, indole as a signal molecule, can exhibit anti-biofilm effects through bacterial quorum sensing inhibition and indole affects. Therefore, indole can regulate biofilm bacteria especially gram-negative opportunistic pathogens.