Department of Pediatric Dentistry, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China; Jiangsu Key Laboratory of Oral Diseases, Nanjing, China.
Nanjing Stomatological Hospital Medical School of Nanjing University, Nanjing, China.
J Ethnopharmacol. 2021 Dec 5;281:114566. doi: 10.1016/j.jep.2021.114566. Epub 2021 Aug 24.
Tea tree essential oil (TTO) is extracted from the leaves of Melaleuca alternifolia by steam distillation. It is well known for its traditional medicinal uses, particularly for the treatment of bruises, insect bites, skin infections, vertigo, convulsions, toothache, and rheumatism. Earlier research has shown that TTO can effectively inhibit oral microorganisms in the root canals. Enterococcus faecalis (E. faecalis) has been considered to be associated with persistent root canal infections and root canal treatment failure. The biofilm of E. faecalis makes it more vigorous, toxic, and resistant to antibiotics.
In this study, our aim was to evaluate the antimicrobial effects of TTO on planktonic E. faecalis and biofilms compared with 0.2% CHX.
We explored the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), the bacteriostatic rate by MTT assay, the antimicrobial time by time-kill assay, and the effects on cell integrity, the biomass, and bacterial activity of E. faecalis biofilms. Finally, we investigated the microstructure changes of E. faecalis biofilms using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).
The MIC and MBC values were 0.25% and 0.5%, the bacterial inhibition rate, time-kill was dosage dependent, and TTO can effectively destroy membrane integrity. SEM CLSM images revealed that TTO could reduce bacterial aggregation, biofilm thickness and inhibited biofilm formation. The effect of TTO was the same as that of 0.2% CHX at some specific concentrations. In summary, TTO has the potential to be effective against E. faecalis infections.
TTO was able to inhibit E. faecalis by destroying cell membrane, inhibiting the formation of E. faecalis biofilms, and eliminating mature formed biofilms. In this study, TTO has the potential to be further developed as a novel antibacterial drug.
茶树精油（TTO）通过水蒸气蒸馏从互叶白千层的叶子中提取。它以其传统的药用用途而闻名，特别是用于治疗瘀伤、昆虫叮咬、皮肤感染、眩晕、惊厥、牙痛和风湿病。早期的研究表明，TTO 可以有效地抑制根管内的口腔微生物。粪肠球菌（E. faecalis）被认为与持续性根管感染和根管治疗失败有关。粪肠球菌的生物膜使其更具活力、毒性和耐药性。
本研究旨在评估 TTO 对浮游粪肠球菌和生物膜的抗菌效果，并与 0.2% CHX 进行比较。
我们探索了最小抑菌浓度（MIC）和最小杀菌浓度（MBC）、MTT 测定的抑菌率、时间杀伤测定的抗菌时间以及对粪肠球菌生物膜细胞完整性、生物量和细菌活性的影响。最后，我们使用扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）观察粪肠球菌生物膜的微观结构变化。
MIC 和 MBC 值分别为 0.25%和 0.5%，细菌抑制率、杀菌时间呈剂量依赖性，TTO 能有效破坏细胞膜完整性。SEM CLSM 图像显示 TTO 可减少细菌聚集、生物膜厚度并抑制生物膜形成。在某些特定浓度下，TTO 的效果与 0.2% CHX 相同。综上所述，TTO 具有抑制粪肠球菌感染的潜力。
TTO 通过破坏细胞膜、抑制粪肠球菌生物膜的形成以及消除成熟的生物膜来抑制粪肠球菌。在这项研究中，TTO 有潜力进一步开发为一种新型抗菌药物。
