Phenolic compounds and interaction between aminoglycosides and natural products of Lygodium venustum SW against multiresistant bacteria.

BACKGROUND: The aim of this work was to evaluate the interactions between aminoglycosides and the ethyl-acetate fraction of the fern Lygodium venustum SW (EAFLV) METHODS: The ethyl-acetate fraction was obtained from the ethanol extract of L. venustum and was assayed via the checkerboard method associated with aminoglycosides against two bacterial strains multiresistant to antibiotics. RESULTS: The antibiotic activity of all drugs, when associated with the ethyl-acetate fraction, was enhanced in an additive manner, except for the association between EAFLV and amikacin, which showed a synergistic interaction against the Escherichia coli strain. CONCLUSIONS: The results indicated that L. venustum can be a source of secondary metabolites to be used in association with antibiotics like aminoglycosides in antibiotic chemotherapy against resistant bacteria.