Scientific Information

What is PSK?

PSK is a proteoglycan found in the mushroom Coriolus or Trametes versicolor. The results obtained from a large number of published scientific studies and clinical trials showed that PSK is a powerful immunomodulator capable of stimulating diverse immunological functions.

Depressed Immunity

A depressed immunity can be attributed to a number of causes including advanced age, stress, poor gut barrier function, infection, disease, exposure to carcinogens and treatment with immunosuppressive agents including chemotherapy and radiation therapy.

Cancer Survival Improved

PSK can improve cancer survival by restoring and enhancing cellular immune functions in patients with depressed immunity associated with profound immunosuppression due to radiation and/or chemotherapy or surgical stress after curative resection of cancer.

No Drug Interactions

PSK does not interact with other drugs nor affect hepatic drug-metabolizing enzyme activities indicating that drug efficacy is not affected by PSK when used with other medications.

Complementary Treatment

PSK is most effective when combined with a front-line anticancer treatment regimen (chemotherapy, radiation therapy or surgery) for patients with various types of cancer. Randomised controlled clinical trials and meta-analysis showed that overall survival and disease-free survival are improved in patients treated with adjuvant immunotherapy plus PSK.

PSK is also beneficial for maintaining general immune health with no reported adverse side effects.

Substance Extraction

The substance extracted from Coriolus versicolor by hot-water extraction is an active proteoglycan compound known as PS-K in Japan (polysaccharopeptide-Krestin) and PS-P (polysaccharide-peptide) in China. PSK is used as a generic term for PS-Krestin and PS-P, which have the same chemical and structural characteristics.

Key Words for further research: Coriolus versicolor; Trametes versicolor ;Yun Zhi ; medicinal mushrooms; proteoglycan or polysaccharidepeptide-Krestin (PS-K) or polysaccharide-peptide (PS-P); immunomodulators; immune system; cancer; adjuvant immunotherapy; side effects.