Bottom Line: 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. PSK and PSP, polysaccharide compounds isolated from Coriolus, 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 the side effects of chemotherapy
  Animal studies suggest that PSK can prevent chemotherapy-induced immune suppression, but clinical trials have not been performed to confirm this effect in humans.
• To stimulate the immune system
  Studies in animals and human volunteers suggest that PSK might stimulate the immune system.
• To treat infections
  Coriolus' effects against infections have not been studied in the laboratory or in clinical trials.
• To reduce the side effects of radiation therapy
  Studies in mice and rats suggest that PSK can prevent radiation therapy-induced immune suppression, but this is yet to be proven in clinical trials.

• Passage of dark colored stools
• Darkening of fingernails
• Low-grade toxicities have been reported when used along with chemotherapy agents. However, such effects may be caused by the chemotherapy agents themselves.

PSK is approved for clinical use in Japan. Purified PSK, PSP extracts, or raw Coriolus extract alone or in combination with other herbs were used in clinical studies. However, the clinical effects of these products have not been compared.

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. When used as an adjuvant, PSK appears to improve survival rates in patients with gastric ^{(1) (2)} and colorectal ^{(3) (4) (5)} cancers. Other Coriolus extracts, such as polysaccharide-peptide (PSP) and VPS, are available as dietary supplements. One clinical study demonstrated that when used in conjunction with chemotherapy, PSP may benefit patients with advanced non-small cell lung cancer ⁽⁶⁾. Other clinical 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⁾, and leukemia ⁽¹¹⁾ produced mixed results. A hot water extract of Coriolus, VPS, was found to enhance development of large intestinal tumors in mice ⁽¹²⁾. 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.

• Cancer prevention
• Cancer treatment
• Chemotherapy side effects
• Hepatitis
• Herpes
• Immunostimulation
• Infections
• Radiation therapy side effects
• Strength and stamina

Proteoglycans: Polysaccharide-K (PSK), a beta-1,4-glucan (isolated from the CM-101 strain), polysaccharide-P (PSP), isolated from the COV-1 strain.

Coriolus versicolor is thought to be a biological response modifier. PSK has been found to induce cytokine expression in human peripheral blood mononuclear cells in vitro. In other studies, PSP, as well as Coriolus extract, selectively induced apoptosis of human promyelocytic leukemia HL-60 cells ^{(13) (23)}. It also increased apoptotic cell death in cells that had been treated with camptothecin. In these cells, PSP reduced cellular proliferation, inhibited cell progression through both the S and G2 phases of DNA replication, reduced 3H - thymidine uptake, and prolonged DNA synthesis time ⁽¹⁴⁾. An additional in vitro study showed that a medicinal mushroom blend that included Coriolus inhibited cell proliferation and induced cell cycle arrest at the G2/M phase in the invasive human breast cancer cell line MDA-MB-231 ⁽¹⁵⁾. DNA-microarray analysis indicated that the mushroom extract inhibited the expression of cell cycle regulatory genes and suppressed metastatic behavior through the inhibition of cell adhesion, cell migration, and cell invasion. The inhibition of metastatic behavior was linked to the suppression of urokinase plasminogen activator (uPA) ⁽¹⁵⁾. PSP has also been shown to inhibit the 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 of synergism 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 immune suppression due to cyclophosphamide in animal models. Peritoneal macrophages isolated from mice that were fed PSP show increased production of reactive nitrogen intermediates, superoxide anions, and tumor necrosis factor ⁽¹⁸⁾. PSP also shows analgesic activity in mouse models ⁽¹⁹⁾.

Non-small cell lung cancer patients have increased leukocyte and neutrophil counts, and increased serum IgG and IgM after consumption of PSP ⁽⁶⁾. Healthy volunteers as well as breast cancer patients who used a formula containing Coriolus and Salvia were found to have elevated counts of T-helper lymphocytes (CD4+), a high ratio of CD4+/CD8+, and elevated absolute counts of B-lymphocytes ^{(7) (8)}. TNF-alpha and IL-8 gene expression were also found to be significantly induced after PSK administration in healthy volunteers and gastric cancer patients, although individual response varied ⁽²⁰⁾. PSK was shown to induce apoptosis in promyelomonocytic leukemia HL-60 cells without inducing differentiation, and p38 MAPK (mitogen-activated protein kinas) was found to play an important role in this process ⁽²⁴⁾.

Absorption
Animal studies with radiolabeled PSK show that it is partially decomposed to small molecular products in the digestive tract. The full molecular spectrum of labeled PSK is absorbed within 24 h following oral administration in mice. Peak plasma levels of low molecular weight substances occur at 0.5-1 h in rats and 1-2 h in rabbits, while molecules the size of PSK appear in serum after 4, 10, and 24 h.

Distribution
Radiolabeled PSK or its metabolites were detected in the digestive tract, bone marrow, salivary glands, thymus, adrenal gland, brain, liver, spleen, pancreas, and tumor tissue in sarcoma-bearing mice. Activity remained high longest in the liver and bone marrow.

Excretion
Approximately 70% of radiolabeled PSK is excreted in expired air, 20% in feces, 10% in urine, and 0.8% in bile. Approximately 86% is excreted within 24 h.
⁽⁴⁾

Adverse reactions from Coriolus are rare. But passage of dark colored stools (not originating from occult blood) ⁽²¹⁾, darkening of fingernails ⁽²²⁾, and low-grade hematological and gastrointestinal toxicities have been reported when used in conjunction with chemotherapy agents ⁽³⁾. However, such effects may be caused by the chemotherapy agents themselves.

None known.

None known.