Protective effect of Caffeic Acid Phenethyl Ester (CAPE) against oxidative stress

The antioxidant properties of several polyphenolics of propolis have been reported, however their protective effect against oxidative stress considering cell integrity is scarce. In this study, we evaluated the cellular antioxidant activity (CAA) of caffeic acid phenetyl ester (CAPE), rutin and galangin (Sonoran propolis constituents) using two murine cell lines derived from different immunological lineages (B-cell lymphoma and macrophages), based on the fluorescence of intracellularly oxidised 2′-7′-dichlorofluorescein (DCF) probe, together with cell morphology analysis and membrane integrity assessment by flow cytometry. CAPE (5 μM) showed the highest CAA (97.9%) on B-cell lymphoma cells against 1 mM H2O2, followed by rutin (25 μM; 30.9%), meanwhile galangin (25 μM) did not show CAA. CAPE exhibited a higher CAA than the antioxidant controls [quercetin (12.5 μM), ascorbic acid (50 μM) and trolox (10 μM)], and additionally it helped to preserve cellular morphology. Similar effects were observed on macrophage cells, indicating that CAPE has a cellular protective effect against ROS. Further studies are needed to investigate the potential health benefits of CAPE.