Bioactive compounds from the African medicinal plant Cleistochlamys kirkii as resistance modifiers in bacteria

Annamária Kincses, Borisz Varga, Ákos Csonka, Shirley Sancha, Silva Mulhovo, Ana Margarida Madureira, Maria José U. Ferreira, Gabriella Spengler

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5 Citations (Scopus)


Cleistochlamys kirkii (Benth) Oliv. (Annonaceae) is a medicinal plant traditionally used in Mozambique to treat infectious diseases. The aim of this study was to find resistance modifiers in C. kirkii for Gram-positive and Gram-negative model bacterial strains. One of the most important resistance mechanisms in bacteria is the efflux pump-related multidrug resistance. Therefore, polycarpol (1), three C-benzylated flavanones (2–4), and acetylmelodorinol (5) were evaluated for their multidrug resistance-reverting activity on methicillin-susceptible and methicillin-resistant Staphylococcus aureus and Escherichia coli AG100 and AG100 A strains overexpressing and lacking the AcrAB–TolC efflux pump system. The combined effects of antibiotics and compounds (2 and 4) were also assessed by using the checkerboard microdilution method in both S. aureus strains. The relative gene expression of the efflux pump genes was determined by real-time reverse transcriptase quantitative polymerase chain reaction. The inhibition of quorum sensing was also investigated. The combined effect of the antibiotics and compound 2 or 4 on the methicillin-sensitive S. aureus resulted in synergism. The most active compounds 2 and 4 increased the expression of the efflux pump genes. These results suggested that C. kirkii constituents could be effective adjuvants in the antibiotic treatment of infections.

Original languageEnglish
Pages (from-to)1039-1046
Number of pages8
JournalPhytotherapy Research
Issue number6
Publication statusPublished - Jun 2018



  • C-benzylated flavanones
  • Cleistochlamys kirkii
  • Escherichia coli AG100
  • efflux pump
  • methicillin-resistant Staphylococcus aureus
  • quorum sensing

ASJC Scopus subject areas

  • Pharmacology

Cite this

Kincses, A., Varga, B., Csonka, Á., Sancha, S., Mulhovo, S., Madureira, A. M., Ferreira, M. J. U., & Spengler, G. (2018). Bioactive compounds from the African medicinal plant Cleistochlamys kirkii as resistance modifiers in bacteria. Phytotherapy Research, 32(6), 1039-1046.