Cloud mushroom contains several saccharides including polysaccharide peptide (PSP) and polysaccharide-K (PSK, krestin). The protein bound polysaccharides have been found to be immune-modulating and anti-tumor, and their polypeptide moieties are rich in aspartic acid and glutamic acid. By gas chromatography and HPLC, PSP has proved that in addition to glucose, it also contains five other monosaccharides – mannose, xylose, galactose, rhamnose and arabinose. The polysaccharide peptides can be found in the mycelium, while the fruiting body mainly contains polysaccharides{…}
Recent evidence suggested that prostate cancer stem/progenitor cells (CSC) are responsible for cancer initiation as well as disease progression. Unfortunately, conventional therapies are only effective in targeting the more differentiated cancer cells and spare the CSCs. Here, we report that PSP, an active component extracted from the mushroom Turkey tail (also known as Coriolus versicolor), is effective in targeting prostate CSCs. 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. Meanwhile, PSP treatment not only suppressed the ability of PC-3 cells to form prostaspheres under non-adherent culture conditions, but also inhibited their tumorigenicity in vivo, further proving that PSP can suppress prostate CSC properties. To investigate if the anti-CSC effect of PSP may lead to prostate cancer chemoprevention, transgenic mice (TgMAP) that spontaneously develop prostate tumors were orally fed with PSP for 20 weeks. Whereas 100% of the mice that fed with water only developed prostate tumors at the end of experiment, no tumors could be found in any of the mice fed with PSP, suggesting that PSP treatment can completely inhibit prostate tumor formation. Our results not only demonstrated the intriguing anti-CSC effect of PSP, but also revealed, for the first time, the surprising chemopreventive property of oral PSP consumption against prostate cancer.[...]
ScienceDaily (May 24, 2011) — A mushroom used in Asia for its medicinal benefits has been found to be 100 percent effective in suppressing prostate tumour development in mice during early trials, new Queensland University of Technology (QUT) research shows.
Dr Ling, from the Australian Prostate Cancer Research Centre-Queensland and Institute for Biomedical Health & Innovation (IHBI) at QUT, said the results could be an important step towards fighting a disease that kills 3,000 Australian men a year.[...]
Polysaccharide-peptide (PSP) is a protein bound polysaccharide isolated from the COV-1 strain of Yunzhi (Coriolous versicolor mushroom) and made from modern alcohol extraction techniques. Each capsule contains 0.34 grams of PSP. Experimental in-vitro and in-vivo studies have shown PSP inhibits the proliferation of cancer cells including P338 leukemia cells, S 180 cells, Ehrlich ascites, and stomach and lung cancer cells. It also inhibits the growth of some tumors such as the lymphatic tumor of human skin tissue cells. In addition, PSP affects the immune system of mice by stimulating the production of ?\interferons, increasing the phagocytic index and metabolic rate of the reticuloendothilial system and by raising the HC 50 (median hemolytic dose), IgG and PFC (plaque forming cell) values. Human in-vivo experiments have also shown PSP can modulate the immune system by helping to prevent and partly eliminate the side effects of radiation and chemotherapeutic agents used by cancer patients. [...]
Flow cytometry analysis on cell cycle and cell death (apoptosis) of Molt 4 cells indicated that the anticancer mechanism of PSP is related to its ability to induce S-phase cell arrest and apoptosis, respectively. Together, these results suggest that monitor the harvest duration is critical for the quality control of polysaccharopeptide in the biotechnological industry.[...]
Among four PSK subfractions, the highest molecular weight fraction (MW greater than 200 kD) had the most potent stimulating activity. This is the first report regarding direct PSK modulation of cytokine action.[...]
PSP at the doses of 500 or 1000ug/ml produced inhibitory effect on P388 luekemia cells by 79-96%. At the dose of 1000 or 2000ug/ml PSP caused the inhibition of [3H]UR or [3H]TdR incorporation into RNA and DNA in Ehrlich ascites carcinoma cells was found to be the inhibition rate 50-80% or 27-47% respectively.[...]
Further studies are required to clarify the origin of IS and its function in the body. For that purpose, the experimental model used in the present study is useful. Serum levels of IS may serve as a parameter to monitor the efficacy of immunotherapy.[...]
The anti-angiogenic effects of an antitumor protein-bound polysaccharide, PSK, obtained from cultured mycelia of Coriolus
versicolor in basidiomycetes were examined by the mouse dorsal air sac assay. PSK suppressed the mouse hepatoma
MH134-induced angiogenesis when assessed by morphological and biochemical examinations. This finding suggested that
the anti-metastatic effect of PSK is attributed to the suppression of tumor-induced angiogenesis.[...]
This activity in Walker 256 fibrosarcoma cells
increased by 3.6 times and H2O2 concentration, by 2.56 times by PS-K 500 micrograms/ml. Cell proliferation was
consequently suppressed and living cells decreased to less than 50% of the cells cultured without PS-K. Catalase and
glutathione peroxidase activity changed little by PS-K. The sensitivity of cancer cells to PS-K can be predetermined based
on SOD activity in tumor tissue.[...]