Effect of curcumin and 5-bromoindole-3-carboxyaldehyde on the inhibition of Quorum sensig-dependent virulence factors inPseudomonas aeruginosa

Pseudomonas aerugoinosa is a bacterium that causes important nosocomial diseases with high mortality and is classified within the bacteria of the acronym ESKAPE. The virulence of Psuedomonas aeruginosa is mediated by Quorum sensing, a cellular communication system that allows it to modulate the expression of virulence factors such as elastase, protease, siderophores, biofilm, alginate among others, through the LasI / LasR, RhlI / RhlR and PQS systems. Quorum inhibition allows an antivirulence strategy, where it has been shown that molecules such as curmunin and carboxaldehydes have considerable activity for this purpose. In the present work, the ability to inhibit Quorum Sensing-dependent virulence factors in Pseudomonas aeruginosa was evaluated using curcumin and 5- bromoindole-3-carboxaldehyde. The strains evaluated are Pa01, Pa14 and ATCC 27853 at concentrations (1 and 5 µg/ml) for curcumin and (30, 50 and 100 µg/ml) for 5-bromoindole-3-carboxaldehyde. 5-Bromoindole-3-carboxaldehyde significantly inhibited the production of pyocyanin in Pa01 (92.5% at 100 µg/ml), elastase in Pa01 (79.85% at 100 µg/ml), protease in Pa01 (92.8% at 50 µg/ml) and alginate in ATCC 27853 (76.16% at 100 µg/ml). Curcumin showed substantial inhibition of pyocyanin in ATCC 27853 (100% at 5 µg/ml), elastase in Pa14 (56.19% at 5 µg/ml), protease in Pa01 (87.04% at 5 µg/ml) and alginate in Pa01 (48.26% at 5 µg/ml). These findings suggest the potential of these compounds as antivirulence agents, to combat P. aeruginosa infections.