Chlorogenic acid exerts anti-proliferative effects and apoptosis in human colon cancer caco-2 cells. - GreenMedInfo Summary

Chlorogenic acid (CGA) decreases colon cancer-cell proliferation but the combined anti-cancer effects of CGA with its major colonic microbial metabolites, caffeic acid (CA), 3-phenylpropionic acid (3-PPA) and benzoic acid (BA), needs elucidation as they occur together in colonic digesta. Caco-2 cancer cells were treated for 24 h with the four compounds individually (50-1000µM) and as an equimolar ratio (1:1:1:1; MIX). The effective concentration to decrease cell proliferation by 50% (EC) was lower for MIX (431± 51.84 µM) and CA (460 ± 21.88) versus CGA (758 ± 19.09 µM). The ECfor cytotoxicity measured by lactate dehydrogenase release in MIX (527± 75.34 µM) showed more potency than CA (740 ± 38.68 µM). Cell proliferation was decreased by 3-PPA and BA at 1000 µM with no cytotoxicity. Cell-cycle arrest was induced at the S-phase by CA (100 µM), MIX (100 µM), CGA (250 µM) and 3-PPA (500 µM) with activation of caspase-3 by CGA, CA, MIX(500 and 1000 µM). Mitochondrial DNA content was reduced by 3-PPA (1000 µM). The anti-cancer effects occurred at markedly lower concentrations of each compound within MIX than when provided singly, indicating that they function together to enhance anti-colon cancer activities.