Laboratorio de Compuestos Bioactivos, CIBAAL, CONICET - Universidad Nacional de Santiago del Estero, Argentina; Facultad de Ciencias Médicas Universidad Nacional de Santiago del Estero, Argentina.
INBIONATEC, CONICET- Universidad Nacional de Santiago del Estero, Argentina; Facultad de Agronomía y Agroindustrias Universidad Nacional de Santiago del Estero - CONICET, Argentina.
Arch Biochem Biophys. 2023 Aug;744:109670. doi: 10.1016/j.abb.2023.109670. Epub 2023 Jun 17.
The essential oil (EO) of Schinus areira L. (Anacardiaceae) leaves has shown antibacterial activity against Staphylococcus aureus. In this study, we aimed to unravel the mechanisms of its antibacterial action by using bacterial cells and model membranes. First, the integrity of the S. aureus membrane was evaluated by fluorescence microscopy. It was observed that there was an increase in the permeability of cells that was dependent on the EO concentration as well as the incubation time. For a deep comprension of the action of the EO on the lipids, its effect on the membrane fluidity was evaluated on DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine): DMPG (1,2-dimyristoyl-sn-glycero-3-phospho-1'-rac-glycerol) (5:1) liposomes by dynamic light scattering and by using Laurdan doped liposomes. The results indicate that EO produces changes in lipid membrane packing, increasing the fluidity, reducing the cooperative cohesive interaction between phospholipids and increasing access of water or the insertion of some components of the EO to the interior of the membrane. In addition, the potential effect of EO on intracellular targets, such as the increase of cytosolic reactive oxygen species (ROS) and DNA damage, were analyzed. The EO was capable of increasing the production of ROS as well as inducing a partial DNA degradation. Finally, the effect of EO on S. aureus biofilm was tested. These assays showed that EO was able to inhibit the biofilm formation, and also eradicate preformed biofilms. The results show, that the EO seems to have several bacterial targets involved in its antibacterial activity, from the bacterial membrane to DNA. Furthermore, the antibacterial action affects not only planktonic cells but also biofilms; reinforcing the potential application of this EO.
山榄科植物 Schinus areira L. 的精油已显示出对金黄色葡萄球菌的抗菌活性。在这项研究中，我们旨在使用细菌细胞和模型膜来揭示其抗菌作用的机制。首先，通过荧光显微镜评估金黄色葡萄球菌膜的完整性。观察到细胞的通透性增加，这取决于精油的浓度和孵育时间。为了深入了解精油对脂质的作用，评估了其对 DMPC（1,2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱）：DMPG（1,2-二肉豆蔻酰-sn-甘油-3-磷酸-1'-rac-甘油）（5:1）脂质体膜流动性的影响通过动态光散射和使用劳丹掺杂脂质体。结果表明，精油会改变脂质膜的堆积方式，增加流动性，降低磷脂之间的合作粘性相互作用，并增加水或精油某些成分进入膜内部的能力。此外，还分析了精油对细胞内靶标（如细胞质活性氧（ROS）的增加和 DNA 损伤）的潜在影响。精油能够增加 ROS 的产生，并诱导部分 DNA 降解。最后，测试了精油对金黄色葡萄球菌生物膜的影响。这些试验表明，精油能够抑制生物膜的形成，并且还能够消除已形成的生物膜。结果表明，精油似乎对其抗菌活性有几个细菌靶标，从细菌膜到 DNA。此外，抗菌作用不仅影响浮游细胞，还影响生物膜；这增强了这种精油的潜在应用。
