Quorum quenching mediated virulence factor impairment by <i>Pandanus tectorius</i> leaf extract against <i>Chromobacterium violaceum</i>

This study investigated the anti-quorum sensing ability of <i>Pandanus tectorius</i> (PT) leaf extract in suppressing virulence factors including biofilm formation in <i>Chromobacterium violaceum</i> under <i>in vitro</i> conditions. The extract significantly inhibited the biosynthesis of violacein, acyl homoserine lactone, chitinase, exopolysaccharides, haemolysin, and outer membrane vesicles at sub-MIC concentrations of 1.5, 1, and 0.5 mg/ml. Biofilm formation was reduced by 81.46% at a concentration of 1.5 mg/ml. PT leaf extract also downregulated the quorum sensing-associated genes, including <i>cviI</i>, <i>cviR</i>, and <i>vioA</i> of <i>C. violaceum</i>. GC-MS analysis identified 15 major bioactive compounds, which were docked with the cviR master regulator protein. Among those, stigmasterol demonstrated efficient binding at the active site of cviR, with a binding energy of −8.5 kcal/mol. Toxicity assays confirmed the non-toxic nature of the PT extract, highlighting its potential as a safe anti-quorum sensing agent.