In vitro interference of Momordica charantia in the resistance to aminoglycosides

Abstract

In this study, the ethanol extract of Momordica charantia L. (EEMC) (Cucurbitaceae) was tested for its antimicrobial activity against strains of Escherichia coli. The growth of two E. coli strains tested was not inhibited by the extract. The MIC and MBC values were ≥1mg/mL for both strains of E. coli used. A synergistic effect between this extract and aminoglycosides was demonstrated. Similarly, a synergistic effect was observed of chlorpromazine on kanamycin and amikacin, indicating the involvement of an efflux system in the resistance to these aminoglycosides. The checkerboard method with combinations of aminoglycosides and EEMC demonstrated synergism with kanamycin and an additive effect with amikacin and neomycin. It is therefore suggested that extracts from M. charantia could be used as a source of plant-derived natural products with resistance-modifying activity. This is the first report about the modifying antibiotic activity of Momordica charantia, constituting a new weapon against bacterial resistance to antibiotics, as with chlorpromazine. © 2009 Informa UK Ltd.