Antibiofilm and Antihemolytic Activities of Extract Rich in Quercetin against .

biofilm formation is a pivotal mechanism in the development of drug resistance, conferring resilience against conventional antibiotics. This study investigates the inhibitory effects of () Maxim extracts on biofilm formation and their antihemolytic activities, with a particular focus on identifying the active antibiofilm and antihemolysis compound, quercetin. Seven solvent extracts and twelve sub-fractions were evaluated against four strains. The ethyl acetate fraction (10 to 100 μg/mL) significantly hindered biofilm formation by both methicillin-sensitive and -resistant strains. Bioassay-guided isolation of the ethyl acetate extract identified quercetin as the major antibiofilm compound. The ethyl acetate extract was found to contain 391 μg/mg of quercetin and 30 μg/mg of kaempferol. Additionally, the extract exhibited antihemolytic activity attributable to the presence of quercetin. The findings suggest that quercetin-rich extracts from and other quercetin-rich foods and plants hold promise for inhibiting resilient biofilm formation and attenuating its virulence.