Department of Laboratory Medicine, University of Pécs, Medical School, 7624 Pécs, Ifjúság u. 13., Hungary.
János Szentágothai Research Center, University of Pécs, Ifjúság u. 20., 7624 Pécs, Hungary.
Molecules. 2020 May 21;25(10):2390. doi: 10.3390/molecules25102390.
The extreme lipophilicity of essential oils (EOs) impedes the measurement of their biological actions in an aqueous environment. We formulated oil in water type Pickering EO nanoemulsions (AEP) with surface-modified Stöber silica nanoparticles (20 nm) as the stabilizing agent. The antimicrobial activity of AEP and its effects on mature biofilms were compared with those of Tween 80 stabilized emulsion (AET) and ethanolic solution (AEE) of the EO. The antimicrobial activity was evaluated by using the minimum inhibitory concentrations (MIC) and minimum effective concentrations (MEC) of the compounds. On planktonic bacterial and fungal cells beside growth inhibition, colony formation (CFU/mL), metabolic activity, viability, intracellular ATP/total protein (ATP/TP), along with reactive oxygen species (ROS) were also studied. EO nanoemulsion (AEP) showed significantly higher antimicrobial activity than AET and AEE. EO nanoemulsions (AEP) generated superoxide anion and peroxides-related oxidative stress, which might be the underlying mode of action of the EO. Unilamellar liposomes, as a cellular model, were used to examine the delivery efficacy of the EO of our tested formulations. We could demonstrate higher effectiveness of AEP in the EO components' donation compared to AET and AEE. Our data suggest the superiority of the AEP formulation against microbial infections.
精油(EOs)的极端疏水性阻碍了其在水环境中生物活性的测量。我们用表面改性的斯托贝二氧化硅纳米颗粒(20nm)作为稳定剂,制备了油包水型 Pickering EO 纳米乳(AEP)。我们比较了 AEP 的抗菌活性及其对成熟生物膜的影响,与 Tween 80 稳定乳液(AET)和 EO 的乙醇溶液(AEE)的效果进行了比较。通过最小抑菌浓度(MIC)和最低有效浓度(MEC)来评估化合物的抗菌活性。除了抑制浮游细菌和真菌细胞的生长外,还研究了菌落形成(CFU/mL)、代谢活性、活力、细胞内 ATP/总蛋白(ATP/TP)以及活性氧(ROS)。与 AET 和 AEE 相比,EO 纳米乳(AEP)表现出显著更高的抗菌活性。EO 纳米乳(AEP)产生了超氧阴离子和过氧化物相关的氧化应激,这可能是 EO 的作用机制。我们使用作为细胞模型的单层脂质体来检查我们测试配方的 EO 的递药效果。与 AET 和 AEE 相比,我们可以证明 AEP 在 EO 成分的供体中具有更高的功效。我们的数据表明,AEP 配方在对抗微生物感染方面具有优越性。