title: Antibiotic-potentiation activities of four Cameroonian dietary plants against multidrug-resistant Gram-negative bacteria expressing efflux pumps.
abstract: BACKGROUND
  The continuous spread of multidrug-resistant (MDR) bacteria, partially due to efflux pumps drastically reduced the efficacy of the antibiotic armory, increasing the frequency of therapeutic failure. The search for new compounds to potentiate the efficacy of commonly used antibiotics is therefore important. The present study was designed to evaluate the ability of the methanol extracts of four Cameroonian dietary plants (Capsicum frutescens L. var. facilulatum, Brassica oleacera L. var. italica, Brassica oleacera L. var. butyris and Basilicum polystachyon (L.) Moench.) to improve the activity of commonly used antibiotics against MDR Gram-negative bacteria expressing active efflux pumps.
  
  
  METHODS
  The qualitative phytochemical screening of the plant extracts was performed using standard methods whilst the antibacterial activity was performed by broth micro-dilution method.
  
  
  RESULTS
  All the studied plant extracts revealed the presence of alkaloids, phenols, flavonoids, triterpenes and sterols. The minimal inhibitory concentrations (MIC) of the studied extracts ranged from 256-1024 μg/mL. Capsicum frutescens var. facilulatum extract displayed the largest spectrum of activity (73%) against the tested bacterial strains whilst the lower MIC value (256 μg/mL) was recorded with Basilicum polystachyon against E. aerogenes ATCC 13048 and P. stuartii ATCC 29916. In the presence of PAβN, the spectrum of activity of Brassica oleacera var. italica extract against bacteria strains increased (75%). The extracts from Brassica oleacera var. butyris, Brassica oleacera var. italica, Capsicum frutescens var. facilulatum and Basilicum polystachyon showed synergistic effects (FIC ≤ 0.5) against the studied bacteria, with an average of 75.3% of the tested antibiotics.
  
  
  CONCLUSIONS
  These results provide promising information for the potential use of the tested plants alone or in combination with some commonly used antibiotics in the fight against MDR Gram-negative bacteria.
authors.forename: Francesco K
authors.initials: FK
authors.lastname: Touani
authors.forename: Armel J
authors.initials: AJ
authors.lastname: Seukep
authors.forename: Doriane E
authors.initials: DE
authors.lastname: Djeussi
authors.forename: Aimé G
authors.initials: AG
authors.lastname: Fankam
authors.forename: Jaurès A K
authors.initials: JA
authors.lastname: Noumedem
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Dschang, P,O, Box 67, Dschang, Cameroon. kuetevictor@yahoo.fr.
authors.forename: Victor
authors.initials: V
authors.lastname: Kuete
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001937:Brassica / Q000737:chemistry*; D002163:Cameroon; D002212:Capsicum / Q000737:chemistry*; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D005419:Flavonoids / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D018649:Ocimum basilicum / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D005419:Flavonoids; D010936:Plant Extracts