Chemical analysis and antioxidant content of various propolis samples collected from different regions and their impact on antimicrobial activities

Objective: To assess the antioxidant content, antimicrobial and antioxidant activities of various propolis samples. Methods: Seven propolis samples were collected from different locations in Morocco, which are characterized by different plant predominant vegetations. The resin, wax and balsam of hydroalcoholic extract of propolis content were identified, and the antioxidant content was analyzed with the use of HPLC and colorimetric methods. The antioxidant activity was assessed by DPPH, ABTS(+) and ferric reducing power assays. The antimicrobial activity was assessed against bacterial species, including methicillin resistant Staphylococcus aureus and Candida albicans, and expressed as the minimal inhibitory concentration. Results: The propolis samples showed significant variations in the chemical composition and in the antioxidant or antimicrobial activities even when the samples were collected from the same location. Propolis with high resin and low wax content had high level of antioxidant compounds, and strong antioxidant and antimicrobial activities. Gram-positive bacteria, especially, methicillin resistant Staphylococcus aureus were more sensitive to all propolis samples than Gram-negative bacteria and Candida albicans. Conclusions: The chemical composition and the antioxidant and antimicrobial activities of various propolis samples are different and rely on the geographic and plant origin of propolis collection. Propolis samples with low wax and high resin content might be more suitable to be used in future preclinical or clinical investigations.