Interactions of different extracts of propolis with leukocytes and leukocytic enzymes

Extracts of the "bee glue" propolis exhibit well-known antioxidative and anti-inflammatory properties. However, the biochemical mechanisms of propolis effects in wound healing and inflammatory processes are not yet fully understood. Therefore the effects of different ethanolic and aqueous extracts on leukocytes and some of their most important enzymes namely myeloperoxidase, NADPH oxidase and lipoxygenase were investigated. Only high concentrations of propolis extracts inhibited these enzymatic activities but especially the water-soluble derivatives showed stimulatory effect on the activity of commercially available human myeloperoxidase. Leukocytic myeloperoxidase and NADPH oxidase activities were clearly inhibited by propolis extracts probably indirectly due to their excellent radical scavenging properties.