Effects of 14-alpha-lipoyl andrographolide on quorum sensing in Pseudomonas aeruginosa.

ABSTRACT: In Pseudomonas aeruginosa, the quorum-sensing (QS) system is closely related to biofilm formation. We previously demonstrated that 14-alpha-lipoyl andrographolide (AL-1) has synergistic effects on antibiofilm and antivirulence factors (pyocyanin and exopolysaccharide) of P. aeruginosa when combined with conventional antibiotics, while it has little inhibitory effect on its growth. However, its molecular mechanism remains elusive. Here we investigated the effect of AL-1 on QS systems, especially the Las and Rhl systems. This investigation showed that AL-1 can inhibit LasR-3-oxo-C(12)-homoserine lactone (HSL) interactions and repress the transcriptional level of QS-regulated genes. Reverse transcription (RT)-PCR data showed that AL-1 significantly reduced the expression levels of lasR, lasI,

SUBMITTER: Ma L 

PROVIDER: S-EPMC3497202 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature