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Immunomodulation and anti-cancer activity of polysaccharide-protein complexes.

In the last three decades, numerous polysaccharides and polysaccharide-protein complexes have been isolated from mushrooms and used as a source of therapeutic agents. The most promising biopharmacological activities of these biopolymers are their immunomodulation and anti-cancer effects. They are mainly present as glucans with different types of glycosidic linkages such as (1–>3), (1–>6)-beta-glucans and (1–>3)-alpha-glucans, and as true herteroglycans, while others mostly bind to protein residues as polysaccharide-protein complexes. Three antitumor mushroom polysaccharides, i.e. lentinan, schizophyllan and protein-bound polysaccharide (PSK, Krestin), isolated respectively, from Lentinus edodes, Schizophyllum commune and Coriolus versicolor, have become large market items in Japan. Lentinan and schizophyllan are pure beta-glucans, whereas PSK is a protein-bound beta-glucan. A polysaccharide peptide (PSP), isolated from a strain of Coriolus versicolor in China, has also been widely used as an anti-cancer and immunomodulatory agent. Although the mechansim of their antitumor action is still not completely clear, these polysaccharides and polysaccharide-protein complexes are suggested to enhance cell-mediated immune responses in vivo and in vitro and act as biological response modifiers. Potentiation of the host defense system may result in the activation of many kinds of immune cells that are vitally important for the maintenance of homeostasis. Polysaccharides or polysaccharide-protein complexes are considered as multi-cytokine inducers that are able to induce gene expression of vaious immunomodulatory cytokines and cytokine receptors. Some interesting studies focus on investigation of the relationship between their structure and antitumor activity, elucidation of their antitumor mechanism at the molecular level, and improvement of their various biological activities by chemical modifications.[…]

Coriolus versicolor: a medicinal mushroom with promising immunotherapeutic values.

Coriolus versicolor (CV) is a medicinal mushroom widely prescribed for the prophylaxis and treatment of cancer and infection in China. In recent years, it has been extensively demonstrated both preclinically and clinically that aqueous extracts obtained from CV display a wide array of biological activities, including stimulatory effects on different immune cells and inhibition of cancer growth. The growing popularity of aqueous CV extracts as an adjunct medical modality to conventional cancer therapies has generated substantial commercial interest in developing these extracts into consistent and efficacious oral proprietary products. While very limited information is available on the physical, chemical, and pharmacodynamic properties of the active principles present in these extracts, there has been sufficient scientific evidence to support the feasibility of developing at least some of these constituents into an evidence-based immunodulatory agent. In this article, the background, traditional usage, pharmacological activities, clinical effects, adverse reactions, active constituents, and regulatory aspects of CV are reviewed. Presented also in this review are the current uses and administration, potential drug interactions, and contraindication of aqueous extracts prepared from CV.[…]

Treatment of cancer with mushroom products.

Cancer has been attributed to 3 causes: pollution, infection, and poor nutrition. Conventional treatments include surgery, chemotherapy, and radiotherapy. The author proposes that immunotherapy also be considered. Among other environmental influences, dietary deficiencies and carcinogenic viral infections must be investigated and treated wherever possible. It has been suggested that mushrooms, in particular, have a structure that is immunomodulatory because it resembles the proteoglycan structure in the human extracellular matrix, and both are metabolically active. Inasmuch as mitochondria have a bacterial origin, proteoglycans may have a mushroom origin. The author describes a study which shows that natural killer cells can double in number with 8 wk of treatment with Coriolus versicolor. Also described is an epidemiological survey of cancer deaths among Flammulina velutipes farmers in Japan, which found that the mushroom farmers had lower rates of cancer deaths than controls who were not involved in mushroom farming.[…]

Differential effect of Coriolus versicolor (Yunzhi) extract on cytokine production by murine lymphocytes in vitro.

Being one of the commonly used Chinese medicinal herbs, Coriolus versicolor (CV), also named as Yunzhi, was known to possess both anti-tumor and immunopotentiating activities. The present study aimed to investigate the in vitro immunomodulatory effect of a standardized ethanol-water extract prepared from CV on the proliferation of murine splenic lymphocytes using the MTT assay, and the production of six T helper (Th)-related cytokines using the enzyme-linked immunosorbent assay (ELISA) technique. The results showed that the CV extract significantly augmented the proliferation of murine splenic lymphocytes in a time- and dose-dependent manner, maximally by 2.4-fold. Moreover, the production of two Th1-related cytokines, including interleukin (IL)-2 and IL-12, in culture supernatants from the CV extract-activated lymphocytes was prominently upregulated at 48 and 72 h. Positive correlations were found between the levels of these two cytokines and the MTT-based proliferative response. In contrast, the production of two other Th1-related cytokines, including interferon (IFN)-gamma and IL-18, was significantly augmented only at 24 h, but not at 48 and 72 h. On the other hand, the levels of two Th2-related cytokines such as IL-4 and IL-6 were undetectable in the culture supernatants of lymphocytes treated with the CV extract. The CV extract was suggested to be a lymphocyte mitogen by differentially enhancing the production of Th1-related cytokines.[…]

Immunomodulatory activities of Yunzhi and Danshen in post-treatment breast cancer patients.

Breast cancer is the most common cancer among women worldwide. Discomfort and fatigue are usually arisen from anticancer therapy such as surgery, radiotherapy, chemotherapy, hormonal therapy, or combination therapy, because of the suppressed immunological functions. Yunzhi (Coriolus versicolor) can modulate various immunological functions in vitro, in vivo, and in human clinical trials. Danshen (Salvia miltiorrhiza) has been shown to benefit the circulatory system by its vasodilating and anti-dementia activity. The purpose of this clinical trial was to evaluate the immunomodulatory effects of Yunzhi-Danshen capsules in post-treatment breast cancer patients. Eighty-two patients with breast cancer were recruited to take Yunzhi [50 mg/kg body weight, 100% polysaccharopeptide (PSP)] and Danshen (20 mg/kg body weight) capsules every day for a total of 6 months. EDTA blood samples were collected every 2 months for the investigation of immunological functions. Flow cytometry was used to assess the percentages and absolute counts of human lymphocyte subsets in whole blood. Plasma level of soluble interleukin-2 receptor (sIL-2R) was measured by enzyme-linked immunosorbent assay (ELISA). Results showed that the absolute counts of T-helper lymphocytes (CD4+), the ratio of T-helper (CD4+)/T suppressor and cytotoxic lymphocytes (CD8+), and the percentage and the absolute counts of B-lymphocytes were significantly elevated in patients with breast cancer after taking Yunzhi-Danshen capsules, while plasma slL-2R concentration was significantly decreased (all p < 0.05). Therefore, the regular oral consumption of Yunzhi-Danshen capsules could be beneficial for promoting immunological function in post-treatment of breast cancer patients.[…]

Effects of polysaccharide peptides from COV-1 strain of Coriolus versicolor on glutathione and glutathione-related enzymes in the mouse.

The effects of polysaccharide peptide (PSP), an immunomodulator isolated from Coriolus versicolor COV-1, on glutathione (GSH) and GSH-related enzymes was investigated in C57 mouse. Administration of PSP (1-4 micromole/kg, i.p.) produced a transient, dose-dependent depletion (10-37%) of hepatic GSH, with no effect on serum glutamic-pyruvic transaminase (SGPT) activity. Blood GSH was depleted (6-25%) at 3 h, followed by a rebound increase above the control GSH level (20%) at 18 h. The GSSG/GSH ratio, a measure of oxidative stress, was increased 3 h after PSP treatment but returned to normal levels at 24 h. Sub-chronic treatment of PSP (1-4 micromole/kg/day, i.p.) for seven days did not produce any significant changes in hepatic GSH levels and the GSSG/GSH ratio when measured 24 h after the final dose of PSP. PSP had little effect on glutathione transferase (GST), glutathione reductase (GSSG reductase) and glutathione peroxidase (GPX) activities in the liver. However, a dose-dependent increase in blood GPX activity (30-48%) was observed at 3h, which coincided with the increase in the GSSG/GSH ratio. The increase in blood GPX activity may be a responsive measure to deal with the transient oxidative stress induced by PSP treatment. The results showed that PSP only caused a transient perturbation on hepatic glutathione without affecting the GSH-related enzymes such as GST, GSSG reductase and GPX. The observed changes in blood GSH simply reflected the intra-organ translocation of glutathione, as the glutathione-related enzymes were not significantly affected by PSP treatment.[…]

Anti-tumor effect of Coriolus versicolor methanol extract against mouse B16 melanoma cells: in vitro and in vivo study.

Numerous studies have shown immunostimulatory and anti-tumor effects of water and standardized aqueous ethanol extracts derived from the medicinal mushroom, Coriolus versicolor, but the biological activity of methanol extracts has not been examined so far. In the present study we investigated the anti-tumor effect of C. versicolor methanol extract (which contains terpenoids and polyphenols) on B16 mouse melanoma cells both in vitro and in vivo. In vitro treatment of the cells with the methanol extract (25-1600 microg/ml) reduced melanoma cell viability in a dose-dependent manner. Furthermore, in the presence of the methanol extract (200 microg/ml, concentration IC(50)) the proliferation of B16 cells was arrested in the G(0)/G(1) phase of the cell cycle, followed by both apoptotic and secondary necrotic cell death. In vivo methanol extract treatment (i.p. 50 mg/kg, for 14 days) inhibited tumor growth in C57BL/6 mice inoculated with syngeneic B16 tumor cells. Moreover, peritoneal macrophages collected 21 days after tumor implantation from methanol extract-treated animals exerted stronger tumoristatic activity ex vivo than macrophages from control melanoma-bearing mice. Taken together, our results demonstrate that C. versicolor methanol extract exerts pronounced anti-melanoma activity, both directly through antiproliferative and cytotoxic effects on tumor cells and indirectly through promotion of macrophage anti-tumor activity.[…]

The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis.

These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

Protein-bound polysaccharide-K (PSK) directly enhanced IgM production in the human B cell line BALL-1

Protein-bound polysaccharide-K (PSK) prepared from the basidiomycete Coriolus versicolor has been used as a biological response modifier for the treatment of cancer patients. Many studies describing the immunomodulatory effects and direct anti-cancer effects of PSK have been reported. Most of studies describing the immunomodulatory effects focused on cellular immunity, although there were several studies which focused on humoral immunity where PSK was shown to be able to induce antibody production in vivo. However, even in these humoral immunity studies, it is thought that the enhancement of antibody production was due to the activation of cellular immunity. In this study, we investigated the direct effect of PSK on B cells and discovered that PSK was able to enhance IgM production in the human B cell line BALL-1. Furthermore, BALL-1 was shown to have the characteristic features of B-1a cells, which are independently involved in the primary immune response. These results show that there is a possibility that PSK directly acts on B cells and simultaneously enhances both humoral immunity and cellular immunity.[…]