RESUMO
An extract from Salvia officinalis (Sage) leaves showed antimicrobial activity against vancomycin-resistant enterococci (VRE). We isolated the effective compound and identified it as oleanolic acid, a triterpenoid. We also tested antimicrobial activity of similar triterpenoids, ursolic acid, uvaol, betulinic acid and betulin. We found that ursolic acid also showed antimicrobial activity against VRE. The minimum inhibitory concentrations (MICs) of oleanolic acid and ursolic acid were 8 and 4 microg/ml, respectively. These two compounds also showed antimicrobial activity against Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA). These compounds showed bactericidal activity against VRE at least for 48 h when added at concentrations that were two-times higher than their MICs.
Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecium/efeitos dos fármacos , Ácido Oleanólico/farmacologia , Salvia officinalis/química , Resistência a Vancomicina , Antibacterianos/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ácido Oleanólico/isolamento & purificação , Vancomicina/farmacologiaRESUMO
We found that a crude extract from Salvia officinalis (sage) reduced the minimum inhibitory concentrations (MICs) of aminoglycosides in vancomycin-resistant enterococci (VRE). We isolated the effective compound from the extract and identified it as carnosol, one of diterpenoids. Carnosol showed a weak antimicrobial activity, and greatly reduced the MICs of various aminoglycosides (potentiated the antimicrobial activity of aminoglycosides) and some other types of antimicrobial agents in VRE. Carnosic acid, a related compound, showed the similar activity. The effect of carnosol and carnosic acid with gentamicin was synergistic.
