Quorum sensing (QS) a cell density-dependent regulation of virulent bacterial gene expression which regulates pathogenesis of bacterial infection. QS is an effective strategy for the development of novel antimicrobial agents which can overcome antibiotic resistance. In the present study, anti quorum sensing activities of ethanolic extracts of medicinal plants Curcuma longa, Ocium tenuiflorum, Aegle marmelos, Eucalyptus globules, Azadirachta indica and Cynodon dactylon against quorum sensing mediated virulence factors such as twitching motility, biofilm production, pyocyanin production and proteolytic activity of Pseudomonas aeruginosa has been carried out. Among the plants Eucalyptus globules revealed maximum inhibition of QS mediated virulence factors. Twisting motility, biofilm formation and total protease activity have been shown to inhibited at maximum level by Eucalyptus globules. Cynodon dactylon showed enhanced cell adhesion inhibition. Maximum reduction of pyocyanin production was recorded in Aegle marmelos. The present study revealed potential of these plant extracts in treating microbial infections through cell growth inhibition or quorum sensing inhibitors would suggests the possible utilization for the prevention of bacterial infections.
