Lentinan

About: Lentinan is a research topic. Over the lifetime, 952 publications have been published within this topic receiving 14176 citations.

Immunomodulation and Anti-Cancer Activity of Polysaccharide- Protein Complexes

Abstract: 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.

Fractionation and Purification of the Polysaccharides with Marked Antitumor Activity, Especially Lentinan, from Lentinus edodes (Berk.) Sing. (an Edible Mushroom)

Abstract: Summary Six polysaccharide preparations, lentinan, LC-11, LC-12, LC-13, EC-11, and EC-14, were isolated from the water-soluble extracts of Lentinus edodes (Berk.) Sing., an edible mushroom, by fractional precipitation with ethanol and cetyltrimethylammonium hydroxide, fractional solubilization with acetic acid, and diethylaminoethyl cellulose column chromatography. The first two polysaccharide preparations have a strong antitumor effect; lentinan, especially, markedly inhibited the growth of Sarcoma 180 implanted s.c. in mice, inducing almost complete regression of tumors at doses of 1 mg/kg × 10 with no sign of toxicity. LC-11 was also effective in 5 to 25 mg/kg × 10 doses. The purity and properties of these antitumor polysaccharides are discussed.

KRN7000, a novel immunomodulator, and its antitumor activities.

Abstract: KRN7000, a compound with a novel alpha-galactosylceramide structure, showed potent tumor growth inhibitory activities in B16-bearing mice and markedly stimulated lymphocytic proliferation in allogeneic mixed leukocyte reaction, suggesting that KRN7000 is a biological response modifier. To confirm this suggestion, we examined the abilities of KRN7000 to enhance in vitro and in vivo natural killer (NK) activities, and found that KRN7000 enhanced in vitro and in vivo NK activities, and its potency on in vivo NK activity was much stronger than those of Poly I:C, which is a positive control, or the representative BRMs OK432 and Lentinan. In addition, since spleen cells intravenously treated with KRN7000 also showed potent cytotoxic activities against B16 and EL-4 cells, we evaluated the capability of KRN7000 to prolong the survival period of mice intravenously inoculated with B16 cells or mice intraperitoneally inoculated with EL-4 cells. In these models, KRN7000 (100 micrograms/kg) significantly prolonged the lifespan of mice, and its potency was stronger than that of Mitomycin C, a typical chemotherapeutic agent, in two models. These results demonstrate that KRN7000 would be a useful agent for cancer therapy.

The use of mushroom glucans and proteoglycans in cancer treatment.

Abstract: Immunoceuticals can be considered as substances having immunotherapeutic efficacy when taken orally. More than 50 mushroom species have yielded potential immunoceuticals that exhibit anticancer activity in vitro or in animal models and of these, six have been investigated in human cancers. All are non-toxic and very well tolerated. Lentinan and schizophyllan have little oral activity. Active Hexose Correlated Compound (AHCC) is poorly defined but has shown early clinical promise. Maitake DFraction has limited proof of clinical efficacy to date, but controlled research is underway. 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. (Altern Med Rev 2000;5(1):4-27)