Özet:

Aim: The aim of this study is to examine the antimicrobial, antibiofilm activities, and synergistic effects of the seeds of two Vincetoxicum taxa [Vincetoxicum canescens subsp. pedunculata (VC) and Vincetoxicum fuscatum subsp. fuscatum (VP)] of which some species have been traditionally used to treat neurosis, malaria, scrofula, scabies, internal fever, external cancers, injuries, and wounds. Methods: Antimicrobial activities of ethanolic extracts obtained from seeds were determined by the microdilution method against 5 reference bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae) and 2 reference fungal strains (Candida albicans and Candida parapsilosis). Effect of the extracts on inhibiting biofilm formation and on formed biofilm was determined by the crystal violet method. Minimum biofilm inhibition concentration (MBIC50) and minimum biofilm reduction concentration (MBRC50) were determined by biofilm tests. The microdilution checkerboard method was used to evaluate the synergistic effect between the two extracts against E.coli. Results: The extracts inhibited the tested bacteria and yeasts in the minimum inhibition concentrations (MIC) range of 62.5–250 µg/mL. It was determined that tested VF and VC extracts inhibited biofilm formation by 47%, 39%, 50%, and 34% at 0.5X and 0.25X MIC, respectively, and the MBIC50 value of both extracts was 62.5 µg/mL. In addition, it was determined that the extracts inhibited the preformed biofilm by 54%, 62%, and 56%, and 61% at 1X and 2X MIC, respectively, and the MBRC50 value was 125 µg/mL. It was determined that the extracts showed an additive effect (FIC=0.62) against E.coli. Conclusions: Although the tested extracts have moderate and low antimicrobial effects, they have well effects both in preventing the formation of biofilm and in removing the formed biofilm