Antibiofilm activity of promethazine, deferiprone and Manuka honey in an ex vivo wound model.

This study evaluated the antibiofilm activity of promethazine, deferiprone and Manuka honey against Staphylococcus aureus and Pseudomonas aeruginosa in vitro and ex vivo in a wound model on porcine skin. The minimum inhibitory concentrations (MICs) and the effects of the compounds on biofilms were evaluated. Then, counting colony-forming units (CFUs) and confocal microscopy were performed on biofilms cultivated on porcine skin for evaluation of the compounds. For promethazine, MICs ranging from 97.66-781.25 µg/mL and minimum biofilm eradication concentration (MBEC) values ranging from 195.31-1562.5 µg/mL were found. In addition to reducing the biomass of both species' biofilms. As for deferiprone, the MICs were 512 and >1024 µg/mL, the MBECs were ≥1024 µg/mL, and it reduced the biomass of biofilms. Manuka honey had MICs of 10-40%, MBECs of 20->40% and reduced the biomass of S. aureus biofilms only. Concerning the analyses in the ex vivo model, the compounds reduced (P<0.05) CFU counts for both bacterial species, altering the biofilm architecture. The action of the compounds on biofilms in in vitro and ex vivo tests raises the possibility of using them against biofilm-associated wounds. However, further studies are needed to characterize the mechanisms of action and their effectiveness on biofilms in vivo.