Caffeic acid phenethyl ester (CAPE), a component of propolis, was reported to possess anti-inflammatory, anti-bacterial, anti-viral, and anti-tumor activities. Our aim was to investigate the effect of CAPE on apoptosis in cultured human mucoepidermoid carcinoma (MEC) cell line, MC-3. Apoptotic effects of CAPE were measured by cell viability assays, Western blotting, 4’-6-diamidino-2-phenylindole (DAPI) staining and Live/Dead assay. The result of cell viability assay showed that CAPE displayed a strong growth-inhibitory effect in a concentration-dependent manner against MC-3 cells. Consumption of CAPE resulted in pronounced increase in the cleavage of caspase-3 and PARP, induced nuclear condensation and fragmentation and clearly increased the number of dead cells in MC-3 cells. CAPE also caused the increase in truncated Bid (t-Bid) and the cleavage of caspase-8 and this phenomenon was regulated by death receptor 5 (DR5). In addition, Phosphorylation of AKT and ERK were downregulated by CAPE. Taken together, these results suggest that CAPE is a potent apoptosis-inducing agent in MC-3 cells.

The phenethyl ester of caffeic acid (CAPE), an active component of honeybee propolis extract, is shown to inhibit cancer growth previously. However, studies on human ovarian cancer are largely obscure. This study evaluated the effects of CAPE as a potenti