1 State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, People's Republic of China.
2 Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi 214100, Jiangsu, People's Republic of China.
J Food Prot. 2019 Mar;82(3):379-389. doi: 10.4315/0362-028X.JFP-18-196.
The aim of the present study was to evaluate the quorum sensing (QS) inhibition potential of eugenol and eugenol nanoemulsion against QS-dependent virulence factor production and gene expression, as well as biofilm formation in Pseudomonas aeruginosa. In the current study, eugenol nanoemulsion at a sub-MIC of 0.2 mg/mL specifically inhibited about 50% of the QS-mediated violacein production in Chromobacterium violaceum, as well as the production of N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C-HSL) and C-HSL N-acyl homoserine lactone signal molecules, pyocyanin, and swarming motility in P. aeruginosa. The inhibitive effect of eugenol and its nanoemulsion on the expression of the QS synthase genes was concentration dependent, displaying 65 and 52% expression level for lasI, respectively, and 61 and 45% expression level for rhlI, respectively, at a concentration of 0.2 mg/mL. In addition, the inhibitive effect of eugenol and its nanoemulsion on the expression of the rhlA gene responsible for the production of rhamnolipid was also concentration dependent, displaying 65 and 51% expression level for the rhlA gene, respectively, at a concentration of 0.2 mg/mL. Eugenol and its nanoemulsion also displayed 36 and 63% respective inhibition of biofilm formation by P. aeruginosa at the 0.2 mg/mL concentration. Therefore, the nanoemulsion could be used as a novel QS-based antibacterial and antibiofilm agent for the control of harmful bacteria.
本研究旨在评估丁香酚及其纳米乳液对铜绿假单胞菌群体感应（QS）依赖性毒力因子产生和基因表达以及生物膜形成的QS 抑制潜力。在本研究中，丁香酚纳米乳液在亚最小抑制浓度（MIC）0.2mg/mL 时，特异性抑制了 Chromobacterium violaceum 中约 50%的 QS 介导的紫罗酮产生，以及 N-(3-氧代十二酰基)-l-高丝氨酸内酯（3-氧代-C-HSL）和 C-HSL N-酰基高丝氨酸内酯信号分子、绿脓菌素和 swarm 运动的产生。丁香酚及其纳米乳液对 QS 合酶基因表达的抑制作用呈浓度依赖性，在浓度为 0.2mg/mL 时，lasI 的表达水平分别为 65%和 52%，rhlI 的表达水平分别为 61%和 45%。此外，丁香酚及其纳米乳液对产鼠李糖脂的 rhlA 基因的表达也具有浓度依赖性抑制作用，在浓度为 0.2mg/mL 时，rhlA 基因的表达水平分别为 65%和 51%。丁香酚及其纳米乳液在 0.2mg/mL 浓度时，对铜绿假单胞菌生物膜形成的抑制率分别为 36%和 63%。因此，纳米乳液可作为一种新型的基于 QS 的抗菌和抗生物膜剂，用于控制有害细菌。
