PSK fights cancers and tumors by inhibiting the growth of cancer cells and by “stimulating a host mediated response.” Natural Killer cells are also promoted to enhance the immune system. It is often used in conjunction with chemotherapy to increase cancer survival rates. PSP is being proposed as an inhibitor of HIV replication based on an in vitro study
Tag Archives: cancer
Bioactive Polysaccharides from TCM Herbs as Anti-Cancer Adjuvants
Many fungal and plant derived bio active polysaccharides with a broad range of immunomodulatory activities are found in TCM. Some
such polysaccharides have been developed into drugs and showed clinical efficacy in controlled trials while the majority of such compounds remain as nutraceuticals with only preliminary research. Such polysaccharides are generally non-toxic and also possess other bio activities such as inducing differentiation, stimulating hematopoiesis, anti-metastasis, and antiangiogenesis, which make them ideal adjuvants in modern cancer therapy.
American Cancer Society
Coriolus versicolor is a mushroom used in traditional Asian herbal remedies (see Chinese Herbal Medicine). Two substances extracted from
the mushroom, polysaccharides K (PSK) and polysaccharides-peptide (PSP), are being studied as possible complementary cancer treatments.
Versicolor polysaccharides (VPS), another extract from the mushroom that is sold as a dietary supplement in the United States, is also being studied. A polysaccharide is a carbohydrate formed by a large number of sugar molecules.
Anticancer effects and mechanisms of polysaccharide?K (PSK): implications of cancer immunotherapy.
Abstract
Polysaccharide-K (polysaccharide-Kureha; PSK), also known as krestin, is a unique protein-bound polysaccharide, which has been used as a chemoimmunotherapy agent in the treatment of cancer in Asia for over 30 years. PSK and Polysaccharopeptide (PSP) are both protein-bound polysaccharides which are derived from the CM-101 and COV-1 strains of the fungus Coriolus versicolor by Japanese and Chinese researchers, respectively. Both polysaccharide preparations have documented anticancer activity in vitro, in vivo and in human clinical trials, though PSK has been researched longer and has therefore undergone more thorough laboratory, animal and clinical testing. Several randomized clinical trials have demonstrated that PSK has great potential as an adjuvant cancer therapy agent, with positive results seen in the adjuvant
treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunotherapy or biological response modifier (BRM). BRMs potentially have the ability to improve the “host versus tumor response,” thereby increasing the ability of the host to defend itself from tumor progression. The mechanisms of biological response modification by PSK have yet to be clearly and completely elucidated. Some studies suggest that PSK may act to increase leukocyte activation and response through up-regulation of key cytokines. Indeed, natural killer (NK) and lymphocyte-activated killer (LAK) cell activation has been demonstrated in vivo and in vitro, and recent genetic studies reveal increased expression of key immune cytokines in response to treatment with PSK. An antimetastatic action of PSK has also been demonstrated and is perhaps attributed to its potential to inhibit metalloproteinases and other enzymes involved in metastatic activity. PSK has also been shown to cause differentiation of leukemic cells in vitro, and this effect has been attributed to induction of differentiation cytokines. PSK has further been shown to have antioxidant capacity which may allow it to play a role as a normal tissue chemo- and radio-protector when used in combination with adjuvant or definitive chemotherapy and/or radiotherapy in the treatment of cancer, while it may also enable it to defend the host from oxidative stress. Interestingly, studies have also shown that PSK may actually inhibit carcinogenesis by inhibiting the action of various carcinogens on vulnerable cell lines. This action of PSK may play a role in preventing second primary tumors when an inducing agent, such as tobacco or asbestos, is suspected and may also prevent second malignancies due to the carcinogenic effects of radiotherapy and cytotoxic chemotherapy. Another very important aspect of chemoimmunotherapy, in general is that it may be used on debilitated patients such as those with AIDS and the elderly who might otherwise be denied potentially helpful adjuvant cytotoxic chemotherapy. Further determination of the mechanisms of these anti-cancer, immunostimulating and biological response modifying effects of PSK as well as of other protein-bound polysaccharides is certainly warranted. Indeed, with modern cellular and molecular biology techniques, a better understanding of the specific molecular effects of PSK on tumor cells as well as leukocytes may be determined. Much of the research that has been done on PSK is outlined in this paper and may serve as a foundation toward determining the mechanisms of action of this and other protein-bound polysaccharides in the treatment of cancer. This information may open new doors in the development of novel strategies for the treatment of malignancies using adjuvant immunotherapy in combination with surgery, chemotherapy and/or radiotherapy.
PMID: 12168863 [PubMed – indexed for MEDLINE]
PubMed
U.S. National Library of Medicine
National Institutes of Health
Publication Types, MeSH Terms, Substances
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Effect of Krestin as adjuvant treatment following radical radiotherapy in non?small cell lung cancer patients.
Hayakawa K, Mitsuhashi N, Saito Y, Nakayama Y, Furuta M, Nakamoto S, Kawashima M, Niibe H.
Department of Radiology and Radiation Oncology, Gunma University School of Medicine, Japan.
Abstract
To evaluate the efficacy of Krestin (PSK) as adjuvant treatment after radical radiation therapy (RT) for non-small cell lung cancer (NSCLC), treatment results of 225 patients with NSCLC treated with RT followed by adjuvant administration of PSK between 1976 and 1989 were analyzed. Of these patients, 170 (76%) had squamous cell carcinoma. In the patients with squamous cell carcinoma of the lung, PSK was given only when the tumor showed satisfactory shrinkage (complete or partial response) after completion of RT. The treatment outcomes were compared with those of the responders to RT not receiving PSK. The 5-year survival rates of patients with stages I-II and stage III disease were 39 and 26%, respectively, while the non-administered responder group’s were 17 and 8%. These differences are statistically significant. An improvement in the treatment results with combined use of appropriate immuno-modulating drugs is anticipated in the future. When clinical trials of the efficacy of these drugs are conducted, the agents should be given to the patients with satisfactory tumor regression after RT, although they still take much time and cost.
PMID: 9043766 [PubMed – indexed for MEDLINE]
PubMed
U.S. National Library of Medicine
National Institutes of Health
Publication Types, MeSH Terms, Substances
The immunomodulator PSK induces in vitro cytotoxic activity in tumor cell lines via arrest of cell cycle and induction of apoptosis
Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated.
Antimetastatic Effects of PSK (Krestin), a Protein-bound Polysaccharide Obtained from Basidiomycetes: An Overview
PSK is currently used as an immuno therapeutic agent for gastric colorectal, and lung cancers in Japan. It has virtually no adverse effects, and it can be administered P. over a long term. Consequently, its use need not be limited to the treatment of Cancer, and, as our previous paper suggested, it should in the future prove valuable as a general chemopreventive agent and, as this review shows, as anti metastatic agent. The principal mechanisms of PSK may act as an inhibitor of the motility, invasion, and progression of tumor cells, in addition to its role as an immunomodulator.
Antimetastatic Effects of PSK (Krestin), a Protein-bound Polysaccharide Obtained from Basidiomycetes: An Overview….. View more here:
Anticancer effects and mechanisms of polysaccharide?K (PSK): implications of cancer immunotherapy.
Fisher M, Yang LX.
Radiobiology Laboratory, St. Mary’s Medical Center, California Pacific Medical Center Research Institute, San Francisco
94118, USA.
Abstract
Polysaccharide-K (polysaccharide-Kureha; PSK), also known as krestin, is a unique protein-bound polysaccharide, which
has been used as a chemoimmunotherapy agent in the treatment of cancer in Asia for over 30 years. PSK and
Polysaccharopeptide (PSP) are both protein-bound polysaccharides which are derived from the CM-101 and COV-1 strains
of the fungus Coriolus versicolor by Japanese and Chinese researchers, respectively. Both polysaccharide preparations
have documented anticancer activity in vitro, in vivo and in human clinical trials, though PSK has been researched longer
and has therefore undergone more thorough laboratory, animal and clinical testing. Several randomized clinical trials have
demonstrated that PSK has great potential as an adjuvant cancer therapy agent, with positive results seen in the adjuvant
treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as
an immunotherapy or biological response modifier (BRM). BRMs potentially have the ability to improve the “host versus
tumor response,” thereby increasing the ability of the host to defend itself from tumor progression. The mechanisms of
biological response modification by PSK have yet to be clearly and completely elucidated. Some studies suggest that PSK
may act to increase leukocyte activation and response through up-regulation of key cytokines. Indeed, natural killer (NK)
and lymphocyte-activated killer (LAK) cell activation has been demonstrated in vivo and in vitro, and recent genetic studies
reveal increased expression of key immune cytokines in response to treatment with PSK. An antimetastatic action of PSK
has also been demonstrated and is perhaps attributed to its potential to inhibit metalloproteinases and other enzymes
involved in metastatic activity. PSK has also been shown to cause differentiation of leukemic cells in vitro, and this effect
has been attributed to induction of differentiation cytokines. PSK has further been shown to have antioxidant capacity which
may allow it to play a role as a normal tissue chemo- and radio-protector when used in combination with adjuvant or
definitive chemotherapy and/or radiotherapy in the treatment of cancer, while it may also enable it to defend the host from
oxidative stress. Interestingly, studies have also shown that PSK may actually inhibit carcinogenesis by inhibiting the action
of various carcinogens on vulnerable cell lines. This action of PSK may play a role in preventing second primary tumors
when an inducing agent, such as tobacco or asbestos, is suspected and may also prevent second malignancies due to the
carcinogenic effects of radiotherapy and cytotoxic chemotherapy. Another very important aspect of chemoimmunotherapy,
in general is that it may be used on debilitated patients such as those with AIDS and the elderly who might otherwise be
denied potentially helpful adjuvant cytotoxic chemotherapy. Further determination of the mechanisms of these anti-cancer,
immunostimulating and biological response modifying effects of PSK as well as of other protein-bound polysaccharides is
certainly warranted. Indeed, with modern cellular and molecular biology techniques, a better understanding of the specific
Molecular effects of PSK on tumor cells as well as leukocytes may be determined. Much of the research that has been done
on PSK is outlined in this paper and may serve as a foundation toward determining the mechanisms of action of this and
other protein-bound polysaccharides in the treatment of cancer. This information may open new doors in the development
of novel strategies for the treatment of malignancies using adjuvant immunotherapy in combination with surgery,
chemotherapy and/or radiotherapy.
PMID: 12168863 [PubMed – indexed for MEDLINE]
The culture duration affects the immunomodulatory and anticancer effect of polysaccharopeptide derived from Coriolus versicolor
Cheuk-Lun Lee, Xiaotong Yang, Jennifer Man-Fan Wan
Department of Zoology, Kardoorie Biological Science Building, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
Received 24 December 2003; accepted 5 October 2004
Abstract
Polysaccharopeptide (PSP) derives from the medicinal mushroom Coriolus versicolor is considered a biological response modifier with potential pharmaceutical applications. Significant literatures support the immune and anticancer functions of PSP; however, standardization is of big concern because variable biotechnological factors can affect both the chemical and biological properties of PSP. In this study, the extracts of PSP obtained at different days from the Coriolus versicolor culture were tested in vitro for their immune function on human normal peripheral blood mononuclear cells (PBMC) and cytotoxicity on the human leukemia Molt 4 cells. Over the 10-days culture period, both biomass and peptide/polysaccharide content were increased with time. The increase in proliferation index of PBMC and their production of interleukin 1 beta (IL-1_), tumor necrosis factor alpha (TNF-_) and gamma interferon (IFN-_) in the presence of PHA strengthens the correlation between culture duration and biological potency of PSP. The growth inhibition of the Molt 4 cells by PSP also depended on its maturity. 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.
© 2005 Elsevier Inc. All rights reserved. Keywords: Coriolus versicolor; Polysaccharopeptide; Flow cytometry; High performance liquid chromatography; Peripheral blood mononuclear cells; Molt 4
[Randomized controlled study on adjuvant immunochemotherapy with PSK in curatively resected colorectal cancer. The Cooperative Study Group of Surgical Adjuvant Immunochemotherapy for Cancer of Colon and Rectum]
[Article in Japanese]
Mitomi T, Tsuchiya S, Iijima N, Aso K, Suzuki K, Nishiyama K, Amano T, Takahashi T, Murayama N, Oka H, et al.
Dept. of Surgery II, Tokai University.
Abstract
To evaluate of adjuvant immunochemotherapy with PSK in curatively resected colorectal cancer, randomized controlled
study by 35 institutions in Kanagawa prefecture was conducted. From March 1985 till February 1987, 462 patients were
assigned one of two different regimens. 448 patients (97.0%) of them satisfied the eligibility criteria. Control group
received mitomycin C intravenously on the day and the day after the operations respectively followed by 5-FU orally over
for 6 months. PSK group received in addition to mitomycin C and 5-FU as in control group, PSK orally for over 3 years. By
February 1989, follow up studies of the patients after their operations had been carried out for two years to four years.
The disease free curve and the survival curve of PSK group were higher than those of control group, differences between
the two groups were statistically significant (Disease free curve: P = 0.0096, survival curve: p = 0.0391). From these
results, adjuvant immunochemotherapy with PSK was considered beneficial for curatively resected colorectal cancer.
PMID: 2500070 [PubMed – indexed for MEDLINE]