| Autor: |
Oliveira RC; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Bandeira PN; Science and Technology Centre, Course of Chemistry, State University Vale do Acaraú, Sobral, CE, Brazil., Lemos TLG; Department of Organic and Inorganic Chemistry, Federal University of Ceará, Fortaleza, CE, Brazil., Dos Santos HS; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil.; Science and Technology Centre, Course of Chemistry, State University Vale do Acaraú, Sobral, CE, Brazil., Scherf JR; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Rocha JE; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Pereira RLS; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Freitas TS; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Freitas PR; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Pereira-Junior FN; Center of Agricultural Sciences and of the Biodiversity, Federal University of Cariri, Juazeiro do Norte, CE, Brazil., Marinho MM; Faculty of Education, Sciences and Letters of Iguatu, State University of Ceará, Campus FECLI, Iguatu, CE, Brazil., Marinho EM; Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, Fortaleza, CE, Brazil., Marinho ES; Group of Theoretical Chemistry and Electrochemistry, State University of Ceará, Campus FAFIDAM, Limoeiro do Norte, CE, Brazil., Nogueira CES; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil.; Department of Physics, Regional University of Cariri, Juazeiro do Norte, CE, Brazil., Coutinho HDM; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil., Teixeira AMR; Graduate Program in Biological Chemistry, Department of Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil.; Department of Physics, Regional University of Cariri, Juazeiro do Norte, CE, Brazil. |
| Abstrakt: |
The use of the bacterial efflux pump mechanism to reduce the concentrations of antibiotics in the intracellular to the extracellular region is one of the main mechanisms by which bacteria acquire resistance to antibiotics. The present study aims to evaluate the antibacterial activity of the α,β-amyrin mixture isolated from Protium heptaphyllum against the multidrug-resistant strains of Escherichia coli 06 and Staphylococcus aureus 10, and to verify the inhibition of the efflux resistance mechanisms against the strains of S. aureus 1199B and K2068, carrying the NorA and MepA efflux pumps, respectively. The α,β-amyrin did not show clinically relevant direct bacterial activity. However, the α,β-amyrin when associated with the gentamicin antibiotic presented synergistic effect against the multidrug-resistant bacterial strain of S. aureus 10. In strains with efflux pumps, α,β-amyrin was able to inhibit the action of the efflux protein NorA against Ethidium Bromide. However, this inhibitory effect was not observed in the MepA efflux pump. In addition, when evaluating the effect of standard efflux pump inhibitors, clorptomazine and CCCP, α,β-amyrin showed a decrease in MIC, demonstrating the presence of the efflux mechanism through synergism. Docking studies indicate that α, β-amyrin have a higher affinity energy to MepA, and NorA than ciprofloxacin and norfloxacin. Also, α, β-amyrin bind to the same region of the binding site as these antibiotics. It was concluded that the α, β-amyrin has the potential to increase antibacterial activity with the association of antibiotics, together with the ability to be a strong candidate for an efflux pump inhibitor.Communicated by Ramaswamy H. Sarma. |
