New antimicrobial properties of products derived from Humulus lupulus L. such as antiadherent and antibiofilm activities were\nevaluated. The growth of gram-positive but not gram-negative bacteria was inhibited to different extents by these compounds. An\nextract of hop cones containing 51% xanthohumol was slightly less active against S. aureus strains (MIC range 31.2ââ?¬â??125.0 ????g/mL)\nthan pure xanthohumol (MIC range 15.6ââ?¬â??62.5 ????g/mL).Thespent hop extract, free of xanthohumol, exhibited lower but still relevant\nactivity (MIC range 1-2mg/mL). There were positive coactions of hop cone, spent hop extracts, and xanthohumol with oxacillin\nagainst MSSA and with linezolid against MSSA and MRSA. Plant compounds in the culture medium at sub-MIC concentrations\ndecreased the adhesion of Staphylococci to abiotic surfaces, which in turn caused inhibition of biofilmformation.The rate ofmature\nbiofilm eradication by these products was significant.The spent hop extract atMIC reduced biofilm viability by 42.8%, the hop cone\nextract by 74.8%, and pure xanthohumol by 86.5%.When the hop cone extract or xanthohumol concentration was increased, almost\ncomplete biofilm eradication was achieved (97ââ?¬â??99%). This study reveals the potent antibiofilm activity of hop-derived compounds\nfor the first time.
Loading....