Chemical Properties of Caffeic and Ferulic Acids in Biological System: Implications in Cancer Therapy. A Review

The antioxidant properties of caffeic and ferulic acids in biological systems have been extensively demonstrated. As antioxidants, these compounds prevent the production of reactive oxygen species (ROS), which cause cell lesions that are associated with the development of several diseases, including cancer. Recent findings suggest that the chemoprotective action of these phenolic acids occurs through the following mechanisms: regulation of gene expression, chelation and / or reduction of transition metals, formation of covalent adducts and direct toxicity. The biological efficacy of these promising chemoprotective agents is strongly related with their chemical structure. Therefore, in this study, we discuss the structural characteristics of ferulic and caffeic acids that are responsible for their biological activities, as well as the mechanisms of action involved with the anti-cancer activity. Several reports indicated that the antioxidant effect of these phenylpropanoids results from reactions with free radicals with formation of stable products in the cells. The chelating effect of these compounds was also reported as an important protective mechanism against oxidative. Finally, the lipophilicity of these agents facilitates their entry into the cells, and thus, contributes to the anticancer activity. Keywords: Caffeic acid, ferulic acid, chemical structure, antioxidant activity, anticancer activity, phenolic acids.