Spondias tuberosa Arruda (Anacardiaceae) ethanolic leaf extract as a source of natural products inhibiting quorum sensing and pyocyanin production in planktonic Pseudomonas aeruginosa

Pseudomonas aeruginosa is a multidrug-resistant pathogen whose virulence is tightly regulated by quorum sensing (QS). Targeting QS offers a promising anti-virulence strategy by disarming pathogens without promoting resistance. Here, we screened Brazilian medicinal plant extracts for QS inhibition and identified the ethanolic leaf extract of Spondias tuberosa Arruda (STF) as a potent suppressor of pyocyanin production in planktonic P. aeruginosa cultures, without affecting bacterial growth. STF disrupted QS signaling, as demonstrated by the decreased production of QS mediators detected using a biosensor strain. Phytochemical profiling revealed candidate compounds potentially responsible for this activity. These findings highlight S. tuberosa as a promising natural source of QS inhibitors capable of attenuating P. aeruginosa virulence, particularly during the early stages of infection, and open perspectives for future research into its potential interest in anti-virulence therapeutic approaches. • Spondias tuberosa leaf extract disrupts quorum sensing and strongly inhibits pyocyanin production in Pseudomonas aeruginosa . • The leaf extract exhibits anti-virulence activity without affecting bacterial growth, targeting the Pqs signaling system. • UHPLC-HRMS revealed 77 diverse metabolites in the Spondias tuberosa leaf extract, a potential source of quorum sensing inhibitors.