Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
1. Protein-bound polysaccharides, designated as PSK and PSP, have been isolated from the CM-101 strain and the COV-1 strain, respectively, of the mushroom Coriolus versicolor. This article aims at summarizing existing research findings about PSP since information on PSK is well documented. 2. PSP possesses a molecular weight of approximately 100 kDa. Glutamic and aspartic acids are abundant in its polypeptide component, whereas its polysaccharide component is made up of monosaccharides with alpha-1,4 and beta-1,3 glucosidic linkages. The presence of fucose in PSK and rhamnose and arabinose in PSP distinguishes the two protein-bound polysaccharides, which are otherwise chemically similar. 3. 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. A small peptide with a molecular weight of 16-18 kDa originating from PSP has been produced with antiproliferative and antitumor activities. 4. PSP administered to patients with esophageal cancer, gastric cancer and lung cancer, and who are undergoing radiotherapy or chemotherapy, helps alleviate symptoms and prevents the decline in immune status.
PMID: 9457474 [PubMed – indexed for MEDLINE]
Jin-Xu Zhou, Xin-li Shen, Zu-ming Shen, Xiao-yu Li
Polysaccharide peptide of Coriolus versicolor (PSP) is a new anti-tumor and immunomodulating drug. In this paper PSP showed direct inhibition on the cell proliferation of sarcoma 180 in vitro and inhibitory effect on the growth of murine sarcoma 180 in vivo. Owing to its direct cytotoxic effect was not strong, but at lower concentrations (10-20ug/ml) of PSP promoted the proliferation of T and pre-T cells of mouse thymus, increased the thymus weight, provided more number of lymphocytes, prevented the involuation of thymus in tumor bearing mice and antagonized the anti-tumor action of PSP combined with antilymphocyte serum. It is suggested the principal mechanism of anti-tumor activity of PSP was T-cell mediated cytotoxicity.
It has been known that some polysaccharides and polysaccharide peptide isolated from various natural sources, especially isolated from Basiodiomycetes have certain anti-tumor activities. The polysaccharide contained a main chain of an alpha and beta (1-4) glucan and a tightly bound 15-38% polypeptides (PSP) isolated from Coriolus versicolor (Fr) Quel. (Cov-1) by Professor Qing-yao Yang also exhibited antitumor action against mouse sarcoma 180 in vitro and in vivo. Recent experiments suggest three possible mechanism by which these PSP might act: (1) Potentiating of T-cell mediated cytotoxicity which killed more number of target-tumor cells. (2) Definite concentration of PSP produced direct cytotoxic activity in vitro. (3) Induction of tumorcidal macrophages killed more cancer cells. In this paper the antitumor action of PSP and its possible mechanism are reported.
Coriolus versicolor, all natural, immunotherapy, Coriolus, PSP, PSK, Yun Zhi, Yunzhi, turkey tail, Trametes versicolor, Trametes, immune booster, immune builder, mushroom studies, mushroom science, mushroom benefits, myceila, cancer, tumor, virus, diseases