Biochemical activities of propolis extracts. II. Photodynamic activities.

Ethanolic and aqueous extracts of the "bee glue" Propolis exhibit antioxidative properties and are used as antiinflammatory drugs in folk medicine. In order to standardize the principle activities of prominent components of these extracts, simple biochemical tests have been introduced in the preceding paper. These activity tests prove the high antioxidative and inhibitory capacities of aqueous and ethanolic extracts of propolis in vitro. In the present communication we report on experiments documenting photodynamic quenching properties of these extracts. Using riboflavin, rose bengal or hematoporphyrin as photoactivators and ketomethylthiobutyric acid or crocin as indicators, the protective functions of propolis preparations can be demonstrated. The results indicate that the aqueous extracts are more active than the corresponding ethanolic preparation.