Polysaccharide-K Explained

Polysaccharide-K (Krestin, PSK) is a protein-bound polysaccharide isolated from the mycelium^{[1] [2]} of Trametes versicolor.

Research

PSK is one of the most commonly used medicinal mushroom extracts with a long history as an additive in cancer therapy in Asia, especially in Japan. PSK has adjuvant anti-tumor activity in vitro in various types of cancers, including colorectal, gastric, breast, liver, pancreatic, and lung cancer.^[3]

Preliminary studies examining PSK include its use in conjunction with chemotherapy for colorectal cancer,^{[4] [5]} non-small cell lung carcinoma,^[6] breast cancer,^[7] liver cancer,^[8] and leukemia.^[9]

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.^[10] 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.^[11]

See also

• Medicinal mushrooms
• Polysaccharide peptide

External links

• American Cancer Society's page for Trametes versicolor and Polysaccharide-K.
• Memorial Sloan-Kettering Cancer Center's page for Trametes versicolor and Polysaccharide-K.
• A "Detailed Scientific Review of Trametes versicolor and Polysaccharide-K" by the MD Anderson Cancer Center.
• Trametes versicolor and Polysaccharide-K information from Drugs.com.

Notes and References

1. Book: Yang . Dandan . Zhou . Zijing . Zhang . Lijuan . Progress in Molecular Biology and Translational Science . 2019 . Academic Press . Chapter Eight - An overview of fungal glycan-based therapeutics . 9780128177402 . 135–163 . 24 January 2023.
2. Habtemariam . Solomon . Trametes versicolor (Synn. Coriolus versicolor) Polysaccharides in Cancer Therapy: Targets and Efficacy . Biomedicines . 2020 . 8 . 5 . 135 . 10.3390/biomedicines8050135 . 32466253 . 7277906 . free .
3. M . Fisher . LX . Yang . Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy . Anticancer Research . Anticancer Res . 22 . 3 . 0250-7005 . 12168863 . 2023-12-22 .
4. Oba K, Teramukai S, Kobayashi M, Matsui T, Kodera Y, Sakamoto J . Efficacy of adjuvant immunochemotherapy with polysaccharide K for patients with curative resections of gastric cancer . Cancer Immunology, Immunotherapy . 56 . 6 . 905–11 . June 2007 . 17106715 . 10.1007/s00262-006-0248-1. 161680 . 11030720 .
5. Mitomi T, Tsuchiya S, Iijima N, etal . Randomized, controlled study on adjuvant immunochemotherapy with PSK in curatively resected colorectal cancer. The Cooperative Study Group of Surgical Adjuvant Immunochemotherapy for Cancer of Colon and Rectum (Kanagawa) . Diseases of the Colon and Rectum . 35 . 2 . 123–30 . February 1992 . 1735313 . 10.1007/BF02050666. 68080825 .
6. Hayakawa K, Mitsuhashi N, Saito Y, etal . Effect of Krestin as adjuvant treatment following radical radiotherapy in non-small cell lung cancer patients . Cancer Detection and Prevention . 21 . 1 . 71–7 . 1997 . 9043766.
7. Iino Y, Yokoe T, Maemura M, etal . Immunochemotherapies versus chemotherapy as adjuvant treatment after curative resection of operable breast cancer . Anticancer Research . 15 . 6B . 2907–11 . 1995 . 8669887.
8. Suto T, Fukuda S, Moriya N, etal . Clinical study of biological response modifiers as maintenance therapy for hepatocellular carcinoma . Cancer Chemotherapy and Pharmacology . 33 Suppl . S145–8 . 1994 . 8137477 . 10.1007/BF00686688. 25538345 .
9. Ohno R, Yamada K, Masaoka T, etal . A randomized trial of chemoimmunotherapy of acute nonlymphocytic leukemia in adults using a protein-bound polysaccharide preparation . Cancer Immunology, Immunotherapy . 18 . 3 . 149–54 . 1984 . 6391658 . 10.1007/BF00205503. 24000083 . 11039289 .
10. Kobayashi H, Matsunaga K, Oguchi Y . Antimetastatic effects of PSK (Krestin), a protein-bound polysaccharide obtained from basidiomycetes: an overview . Cancer Epidemiology, Biomarkers & Prevention . 4 . 3 . 275–81 . 1995 . 7606203 .
11. Fisher M, Yang LX . Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy . Anticancer Research . 22 . 3 . 1737–54 . 2002 . 12168863.