- Turkey Tail
- Yun Zhi
For Patients & Caregivers
How It Works
Coriolus versicolor extracts have been studied in cancer patients with some positive results. However, more studies are needed to verify their effects.
Coriolus versicolor is a mushroom that is used in traditional Chinese medicine as a tonic. Polysaccharide compounds from Coriolus called PSK and PSP were shown to improve immune function in patients with certain cancers when used along with chemotherapy.
To prevent and treat cancer
When used in combination with certain chemotherapy regimens, PSK has been shown to benefit patients following surgical removal of stomach and colorectal cancers. Clinical trials in patients with breast cancer, leukemias, and liver cancer do not show beneficial results.
To reduce cancer treatment side effects
Animal studies suggest that PSK can prevent immune suppression caused by chemotherapy or radiation, but clinical trials have not been performed to confirm this effect in humans.
To stimulate the immune system
Studies in animals and humans suggest that PSK might stimulate the immune system.
To treat infections
The effects of Coriolus on infections have not been studied in clinical trials.
For Healthcare Professionals
Coriolus versicolor is a mushroom of the Basidiomycetes class. It is used in traditional Chinese medicine as a tonic, and recent studies suggest that it has immunostimulant and anti-tumor properties. Polysaccharide-K (PSK), a proprietary product derived from Coriolus, was developed for cancer treatment in Japan. Other Coriolus extracts such as polysaccharide-peptide (PSP) and VPS are available as dietary supplements.
When used as an adjuvant, PSK appears to improve survival rates in patients with gastric (1) (2) and colorectal (3) (4) (5) cancers. It may also benefit patients with esophageal cancer (27). One clinical study demonstrated that PSP used in conjunction with chemotherapy may benefit patients with advanced non-small cell lung cancer (6). Studies using Coriolus extract alone or in combination with other botanicals also suggest positive immunomodulatory effects (7) (8). However, studies on breast cancer (9), hepatocellular carcinoma (10) (28), and leukemia (11) produced mixed results. Although a meta-analysis suggests adjuvant Coriolus may lower mortality risk with some types of cancers (29), additional confirmatory studies are needed.
Coriolus extracts are generally well tolerated but minor adverse effects have been reported. Many over-the-counter Coriolus products are not standardized, making it difficult to compare potency between brands. It is also unclear if PSK, PSP, and other Coriolus extracts have comparable effects.
Mechanism of Action
Coriolus versicolor is thought to be a biological response modifier. In vitro, PSP, PSK, and Coriolus extract induces apoptosis in leukemia cells (13) (23) (24). PSP also increased apoptosis in cells treated with camptothecin, reduced proliferation, progression, and 3H-thymidine uptake, and prolonged DNA synthesis time (14). A Coriolus medicinal mushroom blend inhibited cell proliferation and induced G2/M cell cycle arrest in an invasive breast cancer cell line (15). The mushroom extract inhibits expression of cell-cycle regulatory genes and suppresses metastatic behavior via inhibition of cell adhesion, migration, and invasion. Antiproliferative effects were linked to suppression of urokinase plasminogen activator (15). PSP also inhibits interaction between HIV-1 gp120 and CD4 receptor, HIV-1 transcriptase activity, and glycohydrolase enzyme activity associated with viral glycosylation (16).
Several animal studies report synergy between PSK and biologic therapies, including a concanavalin A-bound L1210 vaccine and the IgG2a monoclonal antibody against human colon cancer cells (17). PSP induces cytokine production and T-cell proliferation, and prevents cyclophosphamide-induced immune suppression. Peritoneal macrophages isolated from PSP-fed mice show increased production of reactive nitrogen intermediates, superoxide anions, and TNF (18). PSP also shows analgesic activity in mouse models (19).
In human studies, non-small cell lung cancer patients have increased leukocyte and neutrophil counts after PSP consumption, as well as increased serum IgG and IgM (6). Healthy volunteers and breast cancer patients who used a formula containing Coriolus and Salvia had elevated CD4+ counts, a high CD4+/CD8+ ratio, and elevated absolute counts of B-lymphocytes (7) (8). TNF-alpha and IL-8 gene expression were significantly induced after PSK administration in healthy volunteers and gastric cancer patients, although individual response varied (20).
High doses of a hot water extract of Coriolus enhanced development of large intestinal tumors in mice (12). However, this is not clinically relevant as the dosage was 10-13x higher than what is used in human studies and the mice were injected with known potent carcinogens.