Methanolic extracts of Acer palmatum and Acer pseudosieboldianum have the potential to attenuate the virulence of P. aeruginosa PAO1. - GreenMedInfo Summary

An increasing concern on resistance to multiple-antibiotics has led to the discovery of novel agents and the establishment of new precaution strategy. Numerous plant sources have been widely studied to reduce virulence of pathogenic bacteria by interfering cell-to-cell based communication called quorum sensing (QS). Leaf extracts of 17 gardening trees were collected and investigated for their anti-QS effects using a sensor strainCV026. Methanolic extracts of K4 (), K9 () and K13 () leaves were selected for further experiments based on their antagonism effect on QS without inhibitingCV026 growth. Subsequently, the leaf extracts on QS-mediated virulence ofPAO1 involved in biofilm formation, motility, bioluminescence, pyocyanin production, QS molecules production, andkilling activity were evaluated. The biofilm formation ability and swarming motility ofPAO1 were decreased approximately 50% in the presence of these leaf extracts at a concentration of 1 mg/mL. The expression level ofofPAO1 and pyocyanin production were also reduced. The three leaf extracts also decreased autoinducer (AI) production inPAO1 without direct degradation, suggesting that AI synthesis might have been suppressed by these extracts. The three leaf extracts also showed anti-infection activity inmodel. Taken together, these results suggest that methanolic leaf extracts of K4, K9 and K13 have the potential to attenuate the virulence ofPAO1.