Molecular Insight into the Inhibition of Pseudomonas aeruginosa Quorum Sensing by 5‑Bromoindole-3-carboxaldehyde and Curcumin: A Combined In Vitro Study, Molecular Dynamics, and Docking Studies.

Curcumin and 5-bromoindole-3-carboxaldehyde were tested for their ability to inhibit quorum sensing-dependent virulence factors in Pseudomonas aeruginosa strains Pa01, Pa14, and ATCC 27853. The compounds were evaluated at curcumin (1 and 5 μg/mL) and 5-bromoindole-3-carboxaldehyde (30, 50, and 100 μg/mL). Virulence factorsexoprotease, elastase, pyocyanin, and alginatewere measured. Chemoinformatics properties were analyzed using Molinspiration, Molsoft, Osiris Property Explorer, pkCSM, and SwissADME. Results showed 5-bromoindole-3-carboxaldehyde significantly reduced pyocyanin in Pa01 (92.5% at 100 μg/mL), elastase (79.85% at 100 μg/mL), exoprotease (92.8% at 50 μg/mL), and alginate in ATCC 27853 (76.16% at 100 μg/mL). Curcumin effectively inhibited pyocyanin in ATCC 27853 (100% at 5 μg/mL), elastase in Pa14 (56.19% at 5 μg/mL), exoprotease in Pa01 (87.04% at 5 μg/mL), and alginate (48.26% at 5 μg/mL). Both compounds demonstrated strong inhibition of virulence factors, suggesting their potential as antivirulence agents against P. aeruginosa, a highly resistant bacterium prevalent in nosocomial infections.