Inhibitive Effect of Eugenol and Its Nanoemulsion on Quorum Sensing-Mediated Virulence Factors and Biofilm Formation by Pseudomonas aeruginosa.

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.