Department of Chemical and Environmental Engineering, Aragon Institute of Nanoscience (INA), University of Zaragoza, Campus Río Ebro-Edificio I+D, C/Poeta Mariano Esquillor S/N, 50018 Zaragoza, Spain.
Networking Research Center on Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN, 28029 Madrid, Spain.
Molecules. 2018 Jun 8;23(6):1399. doi: 10.3390/molecules23061399.
Even though essential oils (EOs) have been used for therapeutic purposes, there is now a renewed interest in the antimicrobial properties of phytochemicals and EOs in particular. Their demonstrated low levels of induction of antimicrobial resistance make them interesting for bactericidal applications, though their complex composition makes it necessary to focus on the study of their main components to identify the most effective ones. Herein, the evaluation of the antimicrobial action of different molecules present in EOs against planktonic and biofilm-forming Gram-positive () and Gram-negative () bacteria was assessed. The bactericidal mechanisms of the different molecules, as well as their cytocompatibility, were also studied. Carvacrol, cinnamaldehyde, and thymol exhibit the highest in vitro antimicrobial activities against and , with membrane disruption the bactericidal mechanism identified. The addition of those compounds (≥0.5 mg/mL) hampers biofilm formation and partially eliminates preformed biofilms. The subcytotoxic values of the tested EO molecules (0.015⁻0.090 mg/mL) are lower than the minimum inhibitory and bactericidal concentrations obtained for bacteria (0.2⁻0.5 mg/mL) but are higher than that obtained for chlorhexidine (0.004 mg/mL), indicating the reduced cytotoxicity of EOs. Therefore, carvacrol, cinnamaldehyde, and thymol are molecules contained in EOs that could be used against ⁻ and ⁻mediated infections without a potential induction of bactericidal resistance and with lower cell toxicity than the conventional widely used chlorhexidine.
尽管精油 (EO) 已被用于治疗目的，但现在人们对植物化学物质和 EO 的抗菌特性重新产生了兴趣。它们表现出的低诱导抗菌耐药性水平使它们成为杀菌应用的有趣选择，尽管它们的复杂成分使得有必要专注于研究其主要成分以确定最有效的成分。在此，评估了 EO 中不同分子对浮游生物和生物膜形成的革兰氏阳性（）和革兰氏阴性（）细菌的抗菌作用。还研究了不同分子的杀菌机制及其细胞相容性。香芹酚、肉桂醛和百里香酚对和表现出最高的体外抗菌活性，其杀菌机制为破坏细胞膜。这些化合物（≥0.5 mg/mL）的添加会阻碍生物膜的形成并部分消除已形成的生物膜。测试的 EO 分子的亚细胞毒性值（0.015⁻0.090 mg/mL）低于获得的细菌最低抑菌和杀菌浓度（0.2⁻0.5 mg/mL），但高于获得的洗必泰（0.004 mg/mL），表明 EO 的细胞毒性降低。因此，香芹酚、肉桂醛和百里香酚是 EO 中含有的分子，可用于治疗⁻和⁻介导的感染，而不会潜在地诱导杀菌耐药性，并且细胞毒性低于常规广泛使用的洗必泰。
