Suppressive effects of novel ferulic acid derivatives on cellular responses induced by phorbol ester, and by combined lipopolysaccharide and interferon-γ

A total of 23 ferulic acid (FA) derivatives were synthesized, and investigated for their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate-induced Epstein–Barr virus (EBV) activation and superoxide (O2−) generation. Most of the derivatives showed significant EBV activation suppression or cytotoxicity at a concentration of 100 μM, with FA15 as the most potent suppressor. In both assays, FA6–FA17, bearing straight- or branched-alkyl side chains, exhibited marked suppression of O2− generation, with both FA16 and FA17 being highly active, while FA itself was virtually inactive. The activity differences seen between FA16/FA17 and FA are attributable, at least in part, to their cellular incorporating efficiencies. Further, both FA15 and FA21 attenuated the expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins, while FA did not. Our results suggest that these novel FA derivatives are effective chemopreventive agents.