Effect of curcumin and 5-bromoindole-3-carboxaldehyde on the inhibition of Quorum sensing-dependent virulence factors in Pseudomonas aeruginosa

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, 5 μg/ml) and 5-bromoindole-3-carboxaldehyde (30, 50, 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 anti-virulence agents against P. aeruginosa , a highly resistant bacterium prevalent in nosocomial infections.