Synergistic Effect of Baccharis dracunculifolia DC and Green Propolis with Antimicrobial Drugs against Staphylococcus aureus

Abstract

Abstract: Relevance: This study demonstrated the synergism of various natural preparations in combination with antibiotics, which is a matter of high potential therapeutic interest due to the de- velopment of bacterial resistance to these antibiotic drugs. This synergism is very relevant because it demonstrates that these extracts and their association with these antibiotics may be viable thera- peutic options against the pathogens that are responsible for a high incidence of nosocomial and community infections. Aims: The study investigated the antibacterial activity against Staphylococcus aureus isolates (methicilin-sensitive Staphylococcus aureus (MSSA) and methicilin-resistant Staphylo- coccus aureus (MRSA)) of green propolis and Baccharis dracunculifolia DC. ethanolic extracts com- bined with classical antibiotics. Methods and Results: In the test of the antibacterial activity of the combination of classical antibiotics with natural extracts (ten antibiotics plus one association of two antimicrobial disc diffusions), 25 isolates were used. The isolates were inoculated in Müeller–Hinton agar culture medium containing the green propolis and Baccharis dracunculifolia DC. extracts. Bac- charis dracunculifolia DC ethanolic extract (BDEE) showed higher antibacterial synergistic behavior with the antibiotics tested than green propolis ethanolic extract (PVEE). Conclusions: BDEE was the preparation that showed the best synergistic antimicrobial effect in sub-doses with the tested anti- biotics. These activities may be related to Artepillin C, the major compound in PVEE, and nerolidol, the major compound in BDEE, in synergism with other minority compounds and related antibiotics.