Polysaccharide peptide (PSP) is a protein-bound polysaccharide extracted from the edible mushroom Coriolus versicolor. PSP is currently in the animal-testing phase of research in many countries for use as an anti-tumor drug. It appears to work as a biological response modifier (BRM), enhancing the body's own use of macrophages and T-lymphocytes, rather than directly attacking any tumors.
Polysaccharide Krestin (PSK) was first isolated in Japan in the late 1960s while PSP was isolated about 1983 in China. Each compound has shown remarkable anticancer properties with few side effects. By 1987 PSK accounted for more than 25% of total national expenditure for anticancer agents in Japan.
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- Abba Kastin (2013-01-26). Handbook of Biologically Active Peptides. Academic Press. pp. 180–. ISBN 978-0-12-385096-6.
- Lu H, Yang Y, Gad E, Wenner CA, Chang A, Larson ER, Dang Y, Martzen M, Standish LJ, Disis ML (2011). "Polysaccharide krestin is a novel TLR2 agonist that mediates inhibition of tumor growth via stimulation of CD8 T cells and NK cells". Clin. Cancer Res. 17 (1): 67–76. doi:10.1158/1078-0432.CCR-10-1763. PMC 3017241. PMID 21068144.