Synergistic Antibacterial Activity of Propolis in Combination with Eucalyptus Globulus Essential Oil Against Bacterial Strains Isolated From Bovine Mastitis

• DOI: https://doi.org/10.22533/at.ed.973492412071

• Palavras-chave: Propolis, antimicrobial, Eucalyptus globulus, Baccharis dracunculifolia, artepillin C

• Keywords: Propolis, antimicrobial, Eucalyptus globulus, Baccharis dracunculifolia, artepillin C

• Abstract: In this study we evaluate  the antibacterial effect of Brazilian Green Propolis (BGP) and Brown Propolis (BP)  in combination with Eucalyptus globulus (EG) essential oil against bovine mastitis-causing strains. Prior to the evaluation propolis samples were characterized to determine phenolic total (TF),  flavonoid content (FC), and antioxidant activity. The phenolic and flavonoid contents of BGP were found to be 3.60 ± 1.2 mg mL-1 and 0.58 ± 0.12 mg mL-1, respectively, while for BP, the values ranged from 14.25 ± 0.97 mg mL-1 to 5.46 ± 0.12 mg mL-1. BGP exhibited higher antioxidant activity (DPPH 62.74% and ABTS 69.40%) than BP (DPPH 7.27% and ABTS 12.97 %). The antimicrobial activity against pathogens isolated from isolated from bovine mastitis was evaluated using the macrodilution method, including Escherichia coli, Streptococcus aureus, Staphylococcus dysgalactiae, Staphylococcus agalactiae, Staphylococcus uberis, and Klebsiella oxytoca. The results for the combination of BGP and EG at 8 and 24-hour intervals revealed a significant inhibitory effect on strains of  S. aureus (100.58% ± 0.59; 89.35% ± 0.07), S. agalactiae (101.46% ± 0.19; 72.80% ± 0.30), S. dysgalactiae (100.51% ± 0.19; 72.75% ± 0.19), S. uberis (102.36% ± 0.19; 71.75% ± 0.09), E. coli (99.19% ± 0.95; 70.91% ± 2.38), and K. oxytoca (97.94% ± 0.23; 69.39% ± 0.23). The results suggested that the approach of combining natural compounds might prove useful in preventing mastitis and could help minimize the  overuse of antibiotics to control mastitis.