Antimicrobial, Antibiofilm and Toxicological Assessment of Propolis

Area of Science:

• Natural Products Chemistry
• Microbiology
• Dermatology

Background:

• Antimicrobial resistance poses a significant global health threat.
• Propolis, a bee-derived resin, possesses known antimicrobial and antibiofilm activities.
• Exploring natural alternatives to conventional antimicrobials is crucial for infection control.

Purpose of the Study:

• To evaluate the antimicrobial and antibiofilm efficacy of a Portuguese propolis ethanolic extract.
• To assess the safety of propolis for topical medical applications through toxicological studies.
• To determine propolis's potential as an alternative to antibiotics for treating Staphylococcus infections.

Main Methods:

• Chemical analysis of a 70% propolis ethanolic extract.
• Antimicrobial susceptibility testing on 137 Staphylococcus field isolates.
• Antibiofilm assays on 45 Staphylococcus isolates.
• In vitro toxicological assessment using keratinocytes and fibroblasts.

Main Results:

• Key compounds like pinobanksin and chrysin were identified in the propolis extract.
• All isolates were susceptible to propolis at concentrations ≤6.68 mg/mL; 80% were susceptible to <1 mg/mL.
• Propolis demonstrated significant antibiofilm activity, with 71% inhibition and 88.5% disruption.
• Propolis showed good tolerance in fibroblasts and moderate tolerance in keratinocytes at <1 mg/mL.

Conclusions:

• Propolis possesses significant antimicrobial and antibiofilm effects against Staphylococcus.
• The extract demonstrated favorable toxicity profiles in skin cells, indicating suitability for topical use.
• Propolis presents a promising natural alternative for topical antibacterial treatments, warranting further in vivo investigation.