Antitumor Effects of Orally and Intraperitoneally Administered Chitosan Oligosaccharides (COSs) on S180-Bearing/Residual Mouse.

Chitosan oligosaccharides (COSs) are hydrolysate mixture of chitin and possess various biomedical properties, such as antimicrobial, immunoenhancing, and antitumor effects. Antiproliferation activity of COS and commercially available samples was compared in the terms of A549 and HCT-116 cells. Ten tumor cells were used to estimate cytotoxicity of COS. Although there were some researches on the antitumor effects of COS, we highlighted the in vivo antitumor activities of COS administrated orally and intraperitoneally on S180-bearing/residual mouse. Results turned out that in vitro IC50 values of COS were 48.6 ± 7.0 to 1329.9 ± 93.4 μg/mL against 10 different tumor cell lines. Then, the in vivo experiments proved that the inhibition rate was high up to 58.5%. Significant cell death and necrosis were observed in COS-treated groups by histological analysis. COS stimulated the mRNA expression of tumor necrosis factor alpha. In summary, COS may be considered promising candidate as antitumor functional food or pharmaceutic adjuvant in oncotherapy, especially for patients after surgical resection.