Investigating the phenolic effect of three types of aqueous, ethanolic and glycolic extracts of propolis and honey on antibiotic resistant bacteria

Antibiotic resistance is a growing global crisis, as many pathogenic bacterial strains have developed resistance to commonly used antibiotics. In recent years, researchers have explored the potential of propolis as an alternative or complementary treatment for antibiotic-resistant bacteria. In this study, three types of propolis extracts—ethanolic (PEE), water-based (PWE), and propylene glycol-based (PPE)—were prepared, and their antibacterial effects were evaluated against three resistant bacterial isolates: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antibacterial efficacy of these extracts was also compared to that of honey. Additionally, the total polyphenol content in the propolis extracts and honey samples was measured based on honey standards. The results of the disc diffusion test indicated that Staphylococcus aureus was the most sensitive to the extracts, while Escherichia coli exhibited the highest resistance. Among the propolis extracts, PPE demonstrated the strongest antibacterial activity against all three bacteria, followed by PEE and PWE, respectively. Honey exhibited the weakest antibacterial effect among the tested samples.