Polysaccharide-K


Polysaccharide-K is a protein-bound polysaccharide isolated from the fruitbody of Trametes versicolor.

Research summary

PSK has been the subject of investigation as an experimental adjunctive therapy for various types of cancers in Japan; however, sufficient data to demonstrate its efficacy for such purposes is lacking. Preliminary studies have examined PSK in conjunction with chemotherapy for colorectal cancer, non-small cell lung carcinoma, breast cancer, liver cancer, and leukemia.

PSK chemistry

PSK is a protein polysaccharide consisting of a beta-glucan β-1,4 main chain with β-1,3 and β-1,6 side chains. The approximate molecular weight of PSK is 100,000 Da, and the protein component is reported at the β-1,6 side chain. PSK is isolated from the "CM-101" strain of Trametes versicolor. The analogous compound PSP, is derived from the "COV-1" strain of Trametes versicolor.