State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, and Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
Antimicrob Agents Chemother. 2019 Apr 25;63(5). doi: 10.1128/AAC.02414-18. Print 2019 May.
Biofilm control is a critical approach to the better management of dental caries. Antimicrobial small molecules have shown their potential in the disruption of oral biofilm and control of dental caries. The objectives of this study were to examine the antimicrobial activity and cytotoxicity of a newly designed small-molecule compound, ZY354. ZY354 was synthesized, and its cytotoxicity was evaluated in human oral keratinocytes (HOK), human gingival epithelial cells (HGE), and macrophages (RAW) by CCK-8 assays. Minimal inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum biofilm inhibition concentrations (MBICs), and minimum biofilm reduction concentrations (MBRCs) of ZY354 against common oral streptococci (i.e., , , and ) were determined by microdilution method. The exopolysaccharide (EPS)/bacterium ratio and the dead/live bacterium ratio in the ZY354-treated multispecies biofilms were determined by confocal laser scanning microscopy, and the microbial composition was visualized and quantified by fluorescent hybridization and quantitative PCR (qPCR). The demineralizing activity of ZY354-treated biofilms was evaluated by transverse microradiography. The results showed that ZY354 exhibited low cytotoxicity in HOK, HGE, and RAW cells and exhibited potent antimicrobial activity against common oral streptococci. The EPS and the abundance of were significantly reduced after ZY354 treatment, along with an increased dead/live microbial ratio in multispecies biofilms compared to the level with the nontreated control. The ZY354-treated multispecies biofilms exhibited reduced demineralizing activity at the biofilm/enamel interface. In conclusion, the small-molecule compound ZY354 exhibits low cytotoxicity and remarkable antimicrobial activity against oral streptococci, and it may have a great potential in anticaries clinical applications.
生物膜控制是改善龋齿管理的关键方法。抗菌小分子在破坏口腔生物膜和控制龋齿方面显示出了潜力。本研究的目的是检测一种新设计的小分子化合物 ZY354 的抗菌活性和细胞毒性。ZY354 被合成，并通过 CCK-8 法在人口腔角质细胞（HOK）、人牙龈上皮细胞（HGE）和巨噬细胞（RAW）中评估其细胞毒性。通过微量稀释法测定 ZY354 对常见口腔链球菌（即 、 、 ）的最小抑菌浓度（MIC）、最小杀菌浓度（MBC）、最小生物膜抑制浓度（MBIC）和最小生物膜减少浓度（MBRC）。通过共聚焦激光扫描显微镜测定 ZY354 处理的多物种生物膜中的胞外多糖（EPS）/细菌比和死/活菌比，并通过荧光原位杂交和定量 PCR（qPCR）可视化和定量微生物组成。通过横向显微放射摄影评估 ZY354 处理的生物膜的脱矿活性。结果表明，ZY354 在 HOK、HGE 和 RAW 细胞中表现出低细胞毒性，并对常见口腔链球菌表现出强大的抗菌活性。与未经处理的对照组相比，在 ZY354 处理后，EPS 和 的丰度显著降低，多物种生物膜中的死/活菌比增加。在生物膜/牙釉质界面，经 ZY354 处理的多物种生物膜的脱矿活性降低。总之，小分子化合物 ZY354 对口腔链球菌表现出低细胞毒性和显著的抗菌活性，在抗龋临床应用中可能具有巨大潜力。
