is a common tree fungus, often seen by hikers as a stiff, rounded, horizontal protuberance from tree trunks, with concentric lines of varying color. In
traditional Chinese herbal medicine, this fungus is used to strengthen overall vitality and treat lung and liver problems as well as other conditions.
Currently, extracts of
called polysaccharide-K (PSK) and polysaccharopeptide (PSP) are under study as immune stimulants for use alongside
in the treatment of cancer. These two related substances, made from slightly different strains of the fungus, are thought to act as “biological response modifiers,” meaning that they affect the body’s response to cancer.
According to most but not all reported trials, most of which were performed in Asia, both PSK and PSP can enhance the effects of various forms of standard cancer treatment.1-9
For example, in a 28-day
double-blind, placebo-controlled study of 34 people with advanced non–small-cell lung cancer, use of
Coriolus extracts along with conventional treatment significantly slowed the progression of the disease.2
It is thought that
Coriolus extracts work by stimulating the body’s own cancer-fighting cells.3
PSK and PSP may also have
In addition, very weak evidence hints that extracts of
might be helpful for
A typical dosage of PSK or PSP as an adjunct to standard cancer treatment is 2 to 6 grams daily. For prevention of cancer, some experts recommend 500 mg daily, but there is no real scientific basis for this recommendation.
According to Chinese studies, PSP and PSK appear to be relatively nontoxic, both in the short and long term.9,11,12
Few side effects have been reported in clinical trials. However, safety in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.
Morimoto T, Ogawa M, Orita K, et al. Postoperative adjuvant randomised trial comparing chemo-endocrine therapy, chemotherapy and immunotherapy for patients with stage II breast cancer: 5-year results from the Nishinihon Cooperative Study Group of Adjuvant Chemo-endocrine Therapy for Breast Cancer (ACETBC) of Japan.
Eur J Cancer. 1996;32A:235–242.
Tsang KW, Lam CL, Yan C, et al.
polysaccharide peptide slows progression of advanced non-small cell lung cancer.
Respir Med. 2003;97:618–24.
Fisher M, Yang LX. Anticancer effects and mechanisms of polysaccharide-K (PSK): implications of cancer immunotherapy.
Anticancer Res. 2002;22:1737–54.
Nakazato H, Koike A, Saji S, et al. Efficacy of immunochemotherapy as adjuvant treatment after curative resection of gastric cancer. Study Group of Immunochemotherapy with PSK for Gastric Cancer.
Torisu M, Hayashi Y, Ishimitsu T, et al. Significant prolongation of disease-free period gained by oral polysaccharide K (PSK) administration after curative surgical operation of colorectal cancer.
Cancer ImmunolImmunother. 1990;31:261–268.
Toi M, Hattori T, Akagi M, et al. Randomized adjuvant trial to evaluate the addition of tamoxifen and PSK to chemotherapy in patients with primary breast cancer. 5-year results from the Nishi-Nippon Group of the Adjuvant Chemoendocrine Therapy for Breast Cancer Organization.
Mitomi T, Tsuchiya S, Iijima N, et al. 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).
Dis Colon Rectum. 1992;35:123–130.
Iino Y, Yokoe T, Maemura M, et al. Immunochemotherapies versus chemotherapy as adjuvant treatment after curative resection of operable breast cancer.
Anticancer Res. 1995;15:2907–2912.
Chu KK, Ho SS, Chow AH.
Coriolus versicolor: a medicinal mushroom with promising immunotherapeutic values.
J Clin Pharmacol. 2002;42:976–84.
Rotolo G. The effectiveness of
in the treatment of secondary phenomena associated with HIV. Paper presented at: the 10th International Congress of Mucosal Immunology; June 27-July 1, 1999; Amsterdam, the Netherlands. Poster 8.4.
Jian X, Huang L, Zhou Y, et al. Subchronic toxicity test of polysaccharopeptide of Yun Zhi (PSP). In: Yang QY (ed),
International Symposium on Traditional Chinese Medicine and Cancer: Development and Clinical Validation—Advances Research in PSP. Hong Kong Association for Health Care Ltd; 1999:272–284.
Jin TY. Toxicological research on Yun Zhi polysaccharopeptide (PSP). In: Yan QY (ed),
International Symposium on Traditional Chinese Medicine and Cancer: Development and Clinical Validation—Advances Research in PSP. Hong Kong Association for Health Care Ltd; 1999:76–79.
Last reviewed December 2015 by EBSCO CAM Review Board
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