Turkey tail is a common enough medicinal mushroom [1].
Why try it?
Study [5] explains my interest. There are very few supplements that target stem-like PCa cells. Conventional cancer therapies are thought to fail because the stem-like cells are not targeted. e.g. PCa stem-like cells do not require androgen & so ADT is ineffective against them.
These cells are not true stem cells, but rather PCa cells that have developed stem cell-like properties. Often referred to as progenitor cells. In the study they were identified via the CD133 and CD44 markers. These markers were downregulated during treatment, indicating a retreat from "stemness".
If we can work on the stem population while on a therapy that targets conventional PCa cells, the latter might remain effective longer. Who knows?
...
"T. versicolor contains polysaccharides under basic research, including the protein-bound PSP and B-1,3 and B-1,4 glucans. The lipid fraction contains the lanostane-type tetracyclic triterpenoid sterol ergosta-7,22,dien-3B-ol as well as fungisterol and B-sitosterol." [1]
Polysaccharide-K [PSK] [Polysaccharide-Kureha] was isolated in Japan in 1969 [2]. Sold as Krestin.
Polysaccharide peptide [PSP] was isolated in China in 1983 [3]. It is the reason for using turkey tail for PCa IMO. "It appears to work as a biological response modifier .., enhancing the body's own use of macrophages and T-lymphocytes, rather than directly attacking any tumors."
Pointless to use a product that fails to specify PSP IMO. I have just checked the products on iHerb, Swanson & Vitacost - no luck. However, Oriveda does [4].
[5] (2011 - Hong Kong)
"We found that treatment of the prostate cancer cell line PC-3 with PSP led to the down-regulation of CSC markers (CD133 and CD44) in a time and dose-dependent manner."
[6] The few remaining studies are of little interest, I feel.
[6a] (1995 - Japan)
A Krestin paper that makes reference to work done on DU145 PCa cells, but offers no details.
[6b] (2001 - U.S.)
This study used "Yunzhi (YZ), a proprietary dietary supplement prepared from extracts of Trametes versicolor, also known as Coriolus versicolor"
"Ethanolic extracts (70%) of YZ significantly reduced LNCaP cell growth, down-regulated the levels of secreted PSA, but had less effects on the expression of intracellular PSA and did not affect levels of the androgen receptor. In androgen-unresponsive prostate cancer cells, YZ had a much less pronounced suppressive effect on proliferation of PC-3 and DU-145 cells, compared to LNCaP, and was inactive against JCA-1 cells." {JCA-1 cells are "androgen-refractory"}
[6c] (2011 - U.S.)
This is a ProstaCaid study. "ProstaCaid™ (PC) ... contains mycelium from medicinal mushrooms (Ganoderma lucidum, Coriolus versicolor, Phellinus linteus), saw palmetto berry, pomegranate, pumpkin seed, green tea [40% epigallocatechin-3-gallate (EGCG)], Japanese knotweed (50% resveratrol), extracts of turmeric root (BCM-95®), grape skin, pygeum bark, sarsaparilla root, Scutellaria barbata, eleuthero root, Job's tears, astragalus root, skullcap, dandelion, coptis root, broccoli, and stinging nettle, with purified vitamin C, vitamin D3, selenium, quercetin, citrus bioflavonoid complex, β sitosterolzinc, lycopene, α lipoic acid, boron, berberine and 3.3'-diinodolymethane (DIM)."
& so says nothing of the contribution of the turkey tail specifically.
[7] PSP in non-PCa papers.
[7a] (1998 - Hong Kong)
"PSP is classified as a biological response modifier. It induces, in experimental animals, increased gamma-interferon production, interleukin-2 production, and T-cell proliferation. It also counteracts the depressive effect of cyclophosphamide on white blood cell count, interleukin-2 production and delayed-type hypersensitivity reaction. Its antiproliferative activity against tumor cell lines and in vivo antitumor activity have been demonstrated."
[7b] (2000 - U.S.)
"Two proteoglycans from Coriolus versicolor - PSK (Polysaccharide-K) and PSP (Polysaccharide-Peptide - have demonstrated the most promise. In Japanese trials since 1970, PSK significantly extended survival at five years or beyond in cancers of the stomach, colon-rectum, esophagus, nasopharynx, and lung (non-small cell types), and in a HLA B40-positive breast cancer subset. PSP was subjected to Phase II and Phase III trials in China. In double-blind trials, PSP significantly extended five-year survival in esophageal cancer. PSP significantly improved quality of life, provided substantial pain relief, and enhanced immune status in 70-97 percent of patients with cancers of the stomach, esophagus, lung, ovary, and cervix. PSK and PSP boosted immune cell production, ameliorated chemotherapy symptoms, and enhanced tumor infiltration by dendritic and cytotoxic T-cells. Their extremely high tolerability, proven benefits to survival and quality of life, and compatibility with chemotherapy and radiation therapy makes them well suited for cancer management regimens."
[7c] (2004 - Hong Kong)
"The present study has made use of the S180 tumor-bearing mouse model to investigate the polysaccharopeptide, PSP, isolated from the edible mushroom Coriolus versicolor, a herbal medicine known for its anti-angiogenesis properties. Quantitative analysis of microcorrosion casting of the tumor tissue showed more angiogenic features such as dense sinusoids and hot spots, in control (untreated) than in PSP-treated animals. Immunostaining of tumor tissues with antibody against the endothelial cell marker (Factor VIII) demonstrated a positive correlation in that both the vascular density and tumor weight were lower in mice treated with PSP. Morphometric analysis of corrosion casts revealed that, even though the total amount of new vessel production was reduced, the basic tumor type-specific vascular architecture was retained. However, the expression of vascular endothelial cell growth factor (VEGF) in these tumors was suppressed. In conclusion, anti-angiogenesis should be one of the pathways through which PSP mediated its anti-tumor activity."
[7d] (2005 - Hong Kong)
"The polysaccharide peptide (PSP) isolated from the mycelia of Chinese Medicinal fungus Coriolus versicolor has proven benefits in clinical trials in China but the mechanism of action has not been elucidated. In this study, HL-60 cell line was used to investigate the anti-proliferation and cell death process of PSP. The cytotoxicity of PSP on normal human T-lymphocytes was also evaluated. We show that PSP induced apoptosis of human promyelocytic leukemia HL-60 cells but not of normal human T-lymphocytes. The apoptotic machinery induced by PSP was associated with a decrease in Bcl-2/Bax ratio, drop in mitochondrial transmembrane potential, cytochrome c release, and activation of caspase-3, -8 and -9. Activation of the cellular apoptotic program is a current strategy for the treatment of human cancer, and the selectivity of PSP to induce apoptosis in cancerous and not on normal cells supports its development as a novel anticancer agent."
-Patrick
[1] en.wikipedia.org/wiki/Trame...
[2] en.wikipedia.org/wiki/Polys...
[3] en.wikipedia.org/wiki/Polys...
[4] oriveda.com/coriolus_psp.php
[5] journals.plos.org/plosone/a...
[6a] ncbi.nlm.nih.gov/pubmed/760...
[6b] ncbi.nlm.nih.gov/pubmed/111...
[6c] ncbi.nlm.nih.gov/pubmed/214...
[7a] ncbi.nlm.nih.gov/pubmed/945...
[7b] ncbi.nlm.nih.gov/pubmed/106...
