Antiproliferative effect of chitosan-added kimchi in HT-29 human colon carcinoma cells

The anticancer effects of chitosan-added kimchi were investigated by using an in vitro cellular system with HT-29 human colon carcinoma cells. Two different kinds of chitosan-soluble chitosan with a 90% degree of deacetylation and 3cps viscosity and nonsoluble chitosan with a 95% degree of deacetylation and 22cps viscosity-were used as subingredients to increase anticancer effects of kimchi. The soluble chitosan-added kimchi (SK) and nonsoluble chitosan-added kimchi (NK) were stronger growth inhibitors in HT-29 cells than the control kimchi (CK) according to the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay and the growth inhibition test. Treatment with SK and NK induced apoptosis, as determined by 4,6-diamidino-2-phenylindole staining, and resulted in the up-regulation of Bax expression and down-regulation of Bcl-2, cIAP-1, cellular inhibitor of apoptosis-2, cyclooxygenase-2, inhibitory nitric oxide synthase, and nuclear factor κB (NF-κB) expressions when compared to CK. The antiproliferative and anti-apoptotic effects appeared to be more pronounced in the cells treated with NK. The antiproliferative effects of the chitosan-added kimchi appeared to be associated with the induction of apoptosis through NF-κB or an NF-κB-dependent pathway. These results suggest that chitosan has potential to be a valuable active ingredient in functional kimchi products with anticancer effects.