This study aimed to evaluate the effect of reserpine, a plant-derived indole-alkaloid, against Pseudomonas aeruginosa PAO1 biofilms. The anti-biofilm activity of reserpine was evaluated by crystal violet staining, MTT assay, confocal laser scanning microscopy and scanning electron microscopy. Reserpine effects were also assessed by qRT-PCR of quorum sensing (QS)-regulated genes and biochemical quantification of the QS-mediated virulence factors pyocyanin, rhamnolipids, proteases and elastases. Reserpine reduced biofilm formation, cell motility, virulence factor production, and QS-controlled gene expression. Additionally, molecular docking analysis for AHL synthase LasI and QS transcriptional regulators LasR/MvfR revealed a plausible molecular mechanisms of reserpine QS inhibition. These findings provide insights into the underlying mode of action of reserpine, which may be useful in the development of new drugs against biofilm-related infections.
Keywords: Pseudomonas aeruginosa; Reserpine; anti-biofilm; antivirulence; molecular docking; qRT-PCR.