Caffeic acid-conjugated chitosan derivatives and their anti-tumor activity

In this study, we synthesized caffeic acid (CFA)-conjugated chitosan (ChitoCFA) as an anti-cancer compound. CFA was conjugated to the amine groups of chitosan (ChitoCFA) and its chemical composition was confirmed using (1)H nuclear magnetic resonance spectra, which indicates that specific peaks of CFA was observed at ChitoCFA conjugates. The anti-cancer effects of CFA and ChitoCFA were studied using CT26 colorectal carcinoma cells. In this cytotoxicity study, CFA and ChitoCFA revealed a dose-dependent decrease of cell viability while chitosan had lower cytotoxicity against tumor cells. CFA and ChitoCFA also proved an anti-proliferative effect against tumor cells. In comparison with CFA, ChitoCFA may accelerate an apoptosis of tumor cells. Furthermore, ChitoCFA demonstrated good anti-invasive efficacy at Matrigel(®) invasion assay against tumor cells. We suggest that ChitoCFA is a promising candidate as an anti-cancer compound.