Potential cytoprotection: antioxidant defence by caffeic acid phenethyl ester against free radical-induced damage of lipids, DNA, and proteins

Oxidative stress is considered to be a major cause of cellular injuries in a variety of chronic health problems, such as carcinogenesis and neurodegenerative disorders. Caffeic acid phenethyl ester (CAPE), derived from the propolis of honeybee hives, possesses a variety of biological and pharmacological properties including antioxidant and anticancer activity. In the present study, we focused on the diverse antioxidative functionalities of CAPE and its related polyphenolic acid esters on cellular macromolecules in vitro. The effects on human erythrocyte membrane ghost lipid peroxidation, plasmid pBR322 DNA, and protein damage initiated by the water-soluble initiator 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) and hydrogen peroxide (H2O2) were monitored by formation of hydroperoxides and by DNA nicking assay, single-cell alkaline electrophoresis, and SDS-polyacrylamide gel electrophoresis. Our results showed that CAPE and its related polyphenolic acid esters elicited remarkable inhibitory effects on erythrocyte membrane lipid peroxidation, cellular DNA strand breakage, and protein fragmentation. The results suggest that CAPE is a potent exogenous cytoprotective and antigenotoxic agent against cell oxidative damage that could be used as a template for designing novel drugs to combat diseases induced by oxidative stress components, such as various types of cancer.