Capillary electrophoresis as a green and rapid technique for the quantification of caffeic acid phenethyl ester (CAPE): Correlation between CAPE contents and anti-inflammatory activities of propolis extracts

Caffeic acid phenethyl ester (CAPE) is propolis's most notable bioactive compound. Since CAPE has many pharmacological properties, the bioactivities of propolis can mostly be attributed to its CAPE content. As the administration of propolis extracts to the body for therapeutic purposes increases, reliable determination of the CAPE content of the extracts becomes important. This study developed a green micellar electrokinetic chromatography (MEKC) method to determine the CAPE amount in propolis extracts rapidly. The method was applied for the determination of CAPE amounts in commercial propolis spray samples and two propolis samples collected from beekeepers in Anatolia. Moreover, the anti-inflammatory activities of propolis samples were measured based on the in-vitro inhibitory activity of the tumor necrosis factor-α (TNF-α) enzyme. The correlation between the amount of CAPE and the anti-inflammatory activities of the samples was investigated and found to be 0.90. This high correlation indicates that CAPE has an important role in the anti-inflammatory effect of propolis.