Inhibition of quorum sensing virulente factors of Pseudomonas aeruginosa PAO1 by Ferulago macedonica and Echinophora sibthorpiana extracts and essential oils

This study was conducted to analyse extracts and essential oils of Ferulago macedonica and Echinophora sibthorpiana (Apiaceae) for anti–quorum sensing potential using Pseudomonas aerugonisa PAO1 as biomonitoring system. Anti–quorum sensing screening was carried out by tree different tests which showed that examined samples possessed significant effects in suppressing of some virulent determinants of PAO1. The essential oils of F . macedonica and E . sibthorpiana aerial parts reduced the growth and modified the appearance of P . aeruginosa colonies and flagella to a large extent in twitching and motility assay. In the presence of essential oil of E . sibthorpiana , diameter of the colony was 6.67 mm, the flagella were absent and the color of the colony was changed from green to white. In anti–biofilm assay, the inhibitory activity of E . sibthorpiana was more notable than of F . macedonica . Applied colorimetric test revealed that examined samples strongly reduced the production of pigment pyocyanin where the highest inhibition of its synthesis showed F . macedonica oil (5.22%), followed by E . sibthorpiana oil (10.69%), which was singnificantly bigger potential in comparison to used antibiotics (141.55%).