Effects of caffeic and 5-caffeoylquinic acids on cell viability and cellular uptake in human colon adenocarcinoma cells.

Colorectal cancer is a major cause of morbidity and mortality throughout the world. Issues related to the role of diet in cancer prevention and treatment are featured each year, and, in this context, consumption of hydroxycinanmic acids is associated with reduced risk of chronic diseases including cancer. Therefore, the aim of this study was to evaluate the cellular uptake of caffeic and 5-caffeoylquinic acids and their effects on cell viability, cell cycle, and apoptosis in human colon adenocarcinoma cells (HT-29). HT-29 cells were incubated with different concentrations of caffeic and 5-caffeoylquinic acids (1.25 µM to 80.0 µM) from 0.5 to 96 h. Cellular uptake was analyzed by HPLC and LCMS. Cell viability, cell cycle, and apoptosis was measured, respectively, using MTT method and flow cytometry. Caffeic and 5-caffeoylquinic acids are absorbed, isomerized, and metabolized by HT-29 cells. Both compounds were able to reduce HT-29 cell viability, promoting specific changes in the cell cycle and increased the apoptosis rate. Caffeic acid and 5-caffeoylquinic acid showed inhibitory effects on cell growth, suggesting a modulation of the cell cycle with an increase in apoptosis in human colon adenocarcinoma cells.