Antiproliferative Effect of Chitosan-Added Kimchi in HT-29 Human Colon Carcinoma Cells

Abstract

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 3 cps viscosity and nonsoluble chitosan with a 95% degree of deacetylation and 22 cps viscosity-were used as sub-ingredients 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 kappaB (NF-kappaB) 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-kappaB or an NF-kappaB-dependent pathway. These results suggest that chitosan has potential to be a valuable active ingredient in functional kimchi products with anticancer effects.