Curcumin and 5-bromoindole-3-carboxaldehyde inhibit the production 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 g/ml) and 5-bromoindole-3-carboxaldehyde (30, 50, 100 g/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 g/ml), elastase (79.85% at 100 g/ml), exoprotease (92.8% at 50 g/ml), and alginate in ATCC 27853 (76.16% at 100 g/ml). Curcumin effectively inhibited pyocyanin in ATCC 27853 (100% at 5 g/ml), elastase in Pa14 (56.19% at 5 g/ml), exoprotease in Pa01 (87.04% at 5 g/ml), and alginate (48.26% at 5 g/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.