State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan 610041, China.
Arch Oral Biol. 2021 May;125:105107. doi: 10.1016/j.archoralbio.2021.105107. Epub 2021 Mar 15.
The current study aimed to assess the antimicrobial activity of ursolic acid (UA) against multi-species biofilms formed by Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii, as well as to measure its biocompatibility.
Crystal violet staining, CFU counting, CCK-8 assays and scanning electron microscopy (SEM) were applied to investigate the effect of UA on multi-species biofilms. UA's effect on exopolysaccharides (EPS) production was measured using confocal laser scanning microscopy (CLSM) and the anthrone-sulfuric acid method. Fluorescent in situ hybridization (FISH) was applied to visualize and quantify the microbial composition of multi-species biofilms. Quantitative real-time PCR (qRT-PCR) was used to measure the expression of virulence genes of S. mutans, S. sanguinis, and S. gordonii under UA treatment. Moreover, CCK-8 assays were performed to evaluate its cytotoxicity against human oral keratinocytes (HOKs) and human gingival epithelial cells (HGEs).
The results showed that UA had significant antimicrobial activity against common oral streptococci. UA also reduced the EPS synthesis of oral streptococci and suppressed gtf genes' expression. In addition, UA reduced the proportion of S. mutans in multi-species biofilms. Besides, UA had low cytotoxicity against HOKs and HGEs.
UA exhibited antibiofilm activity against oral pathogenic bacteria and had the potential to be used in dental caries treatment.
本研究旨在评估熊果酸（UA）对变形链球菌、血链球菌和戈登链球菌形成的多物种生物膜的抗菌活性，并测量其生物相容性。
采用结晶紫染色、CFU 计数、CCK-8 检测和扫描电子显微镜（SEM）观察来研究 UA 对多物种生物膜的影响。采用共聚焦激光扫描显微镜（CLSM）和蒽酮-硫酸法测量 UA 对胞外多糖（EPS）产生的影响。荧光原位杂交（FISH）用于可视化和量化多物种生物膜的微生物组成。采用定量实时 PCR（qRT-PCR）测量 UA 处理下变形链球菌、血链球菌和戈登链球菌毒力基因的表达。此外，采用 CCK-8 检测来评估其对人口腔角质细胞（HOKs）和人牙龈上皮细胞（HGEs）的细胞毒性。
结果表明，UA 对常见口腔链球菌具有显著的抗菌活性。UA 还降低了口腔链球菌的 EPS 合成，并抑制了 gtf 基因的表达。此外，UA 降低了多物种生物膜中变形链球菌的比例。此外，UA 对 HOKs 和 HGEs 的细胞毒性较低。
UA 对口腔致病菌具有抗生物膜活性，有潜力用于龋齿治疗。
