<i>In silico</i> and <i>in vitro</i> evaluation of the anti-virulence potential of patuletin, a natural methoxy flavone, against <i>Pseudomonas aeruginosa</i>

Abstract

This study aimed to investigate the potential of patuletin, a rare natural flavonoid, as a virulence and LasR inhibitor against <i>Pseudomonas aeruginosa</i>. Various computational studies were utilized to explore the binding of Patuletin and LasR at a molecular level. Molecular docking revealed that Patuletin strongly interacted with the active pocket of LasR, with a high binding affinity value of -20.96 kcal/mol. Further molecular dynamics simulations, molecular mechanics generalized Born surface area (MM/GBSA), protein-ligand interaction profile (PLIP), and essential dynamics analyses confirmed the stability of the patuletin-LasR complex, and no significant structural changes were observed in the LasR protein upon binding. Key amino acids involved in binding were identified, along with a free energy value of -26.9 kcal/mol. <i>In vitro</i> assays were performed to assess patuletin's effects on <i>P. aeruginosa</i>. At a sub-inhibitory concentration (1/4 MIC), patuletin significantly reduced biofilm formation by 48% and 42%, decreased pyocyanin production by 24% and 14%, and decreased proteolytic activities by 42% and 20% in <i>P. aeruginosa</i> isolate ATCC 27853 (PA27853) and <i>P. aeruginosa</i> clinical isolate (PA1), respectively. In summary, this study demonstrated that patuletin effectively inhibited LasR activity <i>in silico</i> and attenuated virulence factors <i>in vitro</i>, including biofilm formation, pyocyanin production, and proteolytic activity. These findings suggest that patuletin holds promise as a potential therapeutic agent in combination with antibiotics to combat antibiotic-tolerant <i>P. aeruginosa</i> infections.