The free radical scavenging activity of these natural compounds was also evaluated
through their ability to quench the synthetic DPPH radical. This assay provided
information on the reactivity of tested compounds with a stable free radical,
independently of any enzymatic activity. All the compounds under investigation
showed the DPPH radical scavenging action and also in this test propolis extract
with CAPE and CAPE, used alone, showed a higher quenching efficiency.