Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lentinan”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1986

Macrophage-mediated acute-phase transport protein production induced by lentinan.

A new bioactive factor capable of stimulating the production of acute-phase transport proteins, haptoglobin, hemopexin and ceruloplasmin, was found in mouse serum soon after the administration of lentinan, an immunomodulatory polysaccharide. This factor (APPIF) was produced by macrophages, and may regulate the production of acute-phase transport proteins in hepatocytes. The mice given the serum obtained from donor mice 2-6 h after an injection of 10 mg/kg of lentinan showed a marked increase of the acute-phase transport proteins in their serum 4 days after the serum injection. Pretreatment with the antimacrophage agents, carrageenan and mouse Ia antiserum, before the lentinan treatment to donor mice inhibited the production of acute-phase transport proteins in the recipient mice. Thymus or T-cells had no role in the production of APPIF. As the activity of APPIF disappeared after pronase treatment of the serum, APPIF seems to be a peptide compound. Appearance of APPIF is considered to be one of the earliest manifestations of the mode of action of lentinan in addition to its augmented production of vascular dilatation and hemorrhage inducing factor and interleukin-1. The correlation between these inflammatory and immune responses in earlier stages of the host defence mechanisms is also discussed.

Acute-Phase Proteins↗
PubMed1991

The effect of lentinan on proliferative processes in parenchymal organs of rats--I. The effect on pyrimidine and nucleic acid syntheses.

The present study investigated the effect of Lentinan on the biochemical events associated with the pyrimidine and nucleic acid syntheses in the liver, kidney, thymus and spleen of rats. Lentinan was used at a dose of 4 mg/kg/day (twice) and in a single dose of 20 mg/kg. The following changes were observed. (1) The utilization of (14C)orotic acid for the synthesis of uridine components of liver acid-soluble extract and RNA uracil was activated after the administration of both doses of the drug. The specific activity of cytidine components of the acid-soluble extract and RNA were, on the other hand, not affected. The same holds true for the kidney. The ratio of the specific activity of cytidine:uridine components of the acid soluble extract as well as RNA decreased after the administration of both doses of the drug. The specific activity of DNA cytosine and thymine are slightly suppressed in the liver after the administration of a high dose of Lentinan; no effect was observed in the kidney. (2) The uptake of (14C)cytidine by the liver was not affected; the specific activity of DNA cytosine and thymine were increased after the administration of a high dose of Lentinan. (3) The uptake of (14C)thymidine by the liver was not affected; the specific activity of liver DNA thymine was increased after the administration of both doses of the drug. In the thymus an increase of specific activity of DNA thymine has also been observed. (4) Repeated doses of the drug (4 mg/kg for 6 consecutive days) increased the weight of the spleen. The specific activity of DNA thymine of the liver and spleen were significantly increased.

Animals↗
PubMed1992

Enhanced production of interleukin 1 and tumor necrosis factor by peripheral monocytes after lentinan administration in patients with gastric carcinoma.

The effect of intravenous administration of lentinan, an immunopotentiating polysaccharide, on the production of interleukin 1-alpha (IL 1-alpha), interleukin 1-beta (IL 1-beta) and tumor necrosis factor-alpha (TNF-alpha) by monocytes in peripheral blood mononuclear cells (PBM) was studied in patients with gastric carcinoma. Peripheral blood samples were obtained from 10 patients before and 3, 5 and 7 days after a single dose of 2 mg lentinan injection. The ability of monocytes in PBM to produce IL 1-alpha was significantly augmented 3 and 5 days after lentinan administration, as compared with that before treatment. IL 1-beta production was also significantly increased 3, 5 and 7 days after the drug injection. Further, the capacity to produce TNF-alpha was significantly enhanced 3, 5 and 7 days after the drug administration. Thus, it is likely that the augmentation of these cytokine's production may contribute to the antitumor action of lentinan in patients with gastric carcinoma.

Humans↗
PubMed1992

Enhanced induction of lymphokine-activated killer activity after lentinan administration in patients with gastric carcinoma.

In 15 patients with gastric carcinoma, peripheral blood mononuclear cells (PBM) were obtained serially before and 3, 5 and 7 days after lentinan administration. The generation of lymphokine-activated killer (LAK) activity, induced by in vitro activation of PBM with interleukin 2 (IL 2), was significantly augmented 5 days after a single intravenous dose of 2 mg lentinan, when compared with that before lentinan injection. Natural killer (NK) activity of PBM was also significantly enhanced 7 days after the drug injection. However, the distribution of lymphocyte subsets exhibited no significant change following lentinan administration.

Cell Separation↗
PubMed2003

The beta-(1-->6)-branched beta-(1-->3) glucohexaose and its analogues containing an alpha-(1-->3)-linked bond have similar stimulatory effects on the mouse spleen as Lentinan.

The stimulatory effects of the synthetic beta-(1-->6)-branched beta-(1-->3) glucohexaose and its analogues containing an alpha-(1-->3)-linked bond on the mouse spleen were studied for elucidation of the mechanism of their antitumor activity, and their stimulatory effects were compared with Lentinan. The mouse spleen's weight was increased after the intraperitoneal (i.p.) injection of the oligosaccharides compared with the saline group. In addition, routinely hematoxylin and eosin (HE)-stained spleen sections showed that the injection also changed the spleen's histopathology. RNA samples were isolated from splenocytes of oligosaccharides, Lentinan or saline-injected mice. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot showed that the administration of the oligosaccharides or Lentinan enhanced mouse spleen mRNA production of TNF-alpha but not IL-2. The injection also enhanced Concanavalin A (Con A)-induced mouse splenocytes proliferation, but the in vitro administration of the oligosaccharides did not have the proliferation-enhancing effect. Taken together, these results suggest that the synthetic beta-(1-->6)-branched beta-(1-->3) glucohexaose and its analogues containing an alpha-(1-->3)-linked bond have similar stimulatory effects as Lentinan. Additionally, they may exert their antitumor effects through the induction of splenocytes mediated immune responses.

Animals↗
PubMed2001

Systemic administration of lentinan, a branched beta-glucan, enhances long-term potentiation in the rat dentate gyrus in vivo.

We investigated the effects of oral and intravenous application of lentinan, a branched beta-glucan, on the induction of long-term potentiation (LTP) in the rat dentate gyrus in vivo. Oral administration of lentinan (200 mg/kg) enhanced the induction of LTP evoked by sub-threshold tetanic stimulation (20 pulses at 60 Hz) of the perforant pathway without affecting normal synaptic potentials. Intravenous injection of the compound (0.2-10.0 mg/kg) also enhanced the induction of LTP in a bell-shaped manner, whereas it had no effect on LTP evoked by supra-threshold tetanic stimulation (100 pulses at 100 Hz). Structurally related beta-glucans did not mimic the lentinan-triggered enhancement of LTP. These results suggest that peripherally applied lentinan facilitates the synaptic efficacy of the dentate gyrus neurons in vivo.

Adjuvants, Immunologic↗
PubMed2002

Effects of intraperitoneal and intranasal application of Lentinan on cellular response in rats.

Lentinan (Ajinomoto, Japan) was administrated intraperitoneally (i.p.) and intranasally (i.n.) at different doses (1, 5 and 10 mg/kg) to rats. Effectiveness of Lentinan treatment was evaluated by comparative testing of cell activation (establishing the number, glycolytic and acid phosphatase activity, H2O2 production and killing ability against Salmonella enteritidis and Staphylococcus aureus) at two different compartments--peritoneal and broncho-alveolar cavities. The results indicated that Lentinan induced high-grade activation of peritoneal cells (PCs) and especially of broncho-alveolar cells (BACs) with markedly enhanced effector function (killing ability against S. aureus). Generally, Lentinan, known usually with its parenteral routes of application, can be successful to stimulate the host cell response in the respiratory tract by intranasal route of administration.

Adjuvants, Immunologic↗
PubMed2003

Protective activity of Lentinan in experimental tuberculosis.

Protective effects of Lentinan (Ajinomoto, Japan) against Mycobacterium tuberculosis infection were studied by in vitro and in vivo mouse models. The effectiveness of Lentinan administrated intraperitoneally (i.p.) before infection at a dose of 1 mg/kg three times at 2-day intervals was monitored in vivo by several parameters (body temperature; spleen weight; CFU counts of M. tuberculosis in spleen, liver and lung; and histomorphological observations). Peritoneal macrophages obtained from animals treated with Lentinan were greatly stimulated, as assayed by establishing their number, acid phosphatase activity, H2O2 production and killing ability against M. tuberculosis in vitro. The in vivo model demonstrated that administration of Lentinan before infection can mobilize host defense potential and reduce mycobacterial infection.

Adjuvants, Immunologic↗
PubMed1996

Preparation and specificity of antibodies to an anti-tumor beta-glucan, lentinan.

Antibodies against beta-glucan, lentinan from "Shiitake" (Lentinus edodes), were raised in the rabbit by subcutaneous immunization. Our antibodies did not recognize the other polysaccharides such as amylose, dextran, laminarin and galactan. It was proved that lentinan contents in mushroom could be measured by ELISA with the anti-lentinan antisera. Its contents were 3.5 mg/g fresh weight in Lentinus edodes. However, lentinan was not contained in Agaricus brazei, Agaricus bisporus and Ramaria bitrytis.

Animals↗
PubMed1990

[Studies on usefulness of postoperative adjuvant chemotherapy with lentinan in patients with gastrointestinal cancer].

The usefulness of Lentinan, as an agent for postoperative adjuvant therapy, was investigated in patients with gastrointestinal cancer. Sixty-one patients were classified into three stages by a degree of advance for cancer (Stage II, III, IV). Furthermore, each group was put into the control group (C group) and the Lentinan group (L group), received 600 mg/day of Tegafur p. o. only or 600 mg/day of Tegafur p. o. and 2 mg/week of Lentinan i. v., respectively. Then total lymphocyte counts and NK cell activities were measured and analysis of lymphocyte subsets by two color flow cytometry was carried out every two months. The results were as follows: 1) Some parameters were preserved in higher levels in the L group especially in the stage IV. 2) In the stage IV, total lymphocyte counts of the L group were preserved higher levels compared to those of the C group. The same tendency was observed in OKT3, OKT4 and OKT8 positive cell counts. 3) In the stage IV, both OKT8+ x Leu15+ cell (suppressor T cell) and OKT8+ x Leu15- cell (killer T cell) counts tended to decrease in the C group. 4) In the stage IV, the NK cell activities of the L group were preserved in higher level compared to those of the C group. Leu7+ x Leu11-, Leu7+ x Leu11+ and Leu11- x Leu11+ cells counts tended to preserve in the L group. From these results, it was suggested that Lentinan had a marked immunopotentiating efficacy in the stage IV among gastrointestinal cancer patients.

Adult↗
PubMed1990

[Effect of intrapleural and/or intraperitoneal lentinan therapy in carcinomatous pleuritis and peritonitis].

Seventeen lesions in fourteen patients with malignant pleural and/or peritoneal effusion were treated with the intrapleural and/or intraperitoneal Lentinan therapy (4 mg/week x 4). The following results were obtained. Malignant effusion disappeared in four lesions and diminished in two. In ten lesions, the cytological grade decreased. Totally, thirteen lesions (76.5%) revealed clinical effect. Toxicity, caused a high fever in only one case. Subpopulations (CD4, CD8, Leu7, CD8+ CD11+) of pleural or peritoneal effusion mononuclear cells (PEM) and peripheral blood mononuclear cells (PBM) showed no change during the course of Lentinan therapy. NK and anti-Daudi activities of PEM tended to be augmented and high LAK activities of PEM were maintained by Lentinan therapy. However, NK activities of PBM after this therapy were significantly lower than before therapy (p less than 0.05). Augmentation of cytotoxicity in PEM induced by Lentinan may lead to clinical effect. Thus, this therapy may be useful for even patients with end-stage carcinoma.

Ascitic Fluid↗
PubMed1988

[Combination use of lentinan with X-ray therapy in a mouse experimental tumor system (Part I). Basic studies].

Apparent reduction of leukocyte counts was observed in mice irradiated with 1,500 approximately 3,000 rads of X-ray on the left hind leg. This reduction of leukocyte counts was completely protected by the pre-treatment with lentinan before X-ray irradiation. Suppressive effect of X-ray on the antitumor function of lentinan seems to be weak. When treatment with X-ray irradiation and lentinan was applied for mice bearing solid type sarcoma 180, additive effect was obtained by the combination of lentinan before or after X-ray irradiation.

Animals↗
PubMed1987

[Granulopoietic effects of lentinan in mice: effects on GM-CFC and 5-FU-induced leukopenia].

C57BL mice were injected intravenously with an antitumor immunopotentiating polysaccharide, lentinan, to assess its effect on granulopoiesis in normal mice as well as its ability to enhance the recovery from leukopenia induced by 5-fluorouracil (5-FU). Lentinan increased neutrophils and monocytes in peripheral blood as well as granulocyte-macrophage progenitor cells (GM-CFC) in spleen and bone marrow. Administration of 5-FU induced a significant decrease in GM-CFC from day 1 to day 6, and thereafter the number of GM-CFC rebounded. The administration of 5-FU also suppressed white blood cells such as neutrophils, monocytes and lymphocytes. Injection of lentinan one day after 5-FU resulted in prompt restoration of the leukopenia through the recovery of neutrophils, monocytes and lymphocytes as well as prompt and marked rebound of GM-CFC. These results suggest that lentinan may contribute to the recovery from some of the hematopoietic depression in clinical chemoimmunotherapy.

Animals↗
PubMed1985

[Results of phase III study of lentinan].

A follow-up survey of survivals (Oct. 1 '80 to May 1, '84) in a randomized controlled study (Aug. '79 to Sept. 30' 80) of lentinan in combination administration with chemotherapeutic agents such as 5FU + mitomycin C or tegafur on patients with advanced or recurrent gastrointestinal cancer has shown that lentinan has been effective in such cases with regard to the following facts: 1) A life span prolongation effect at the end-point has been observed with statistical significance in lentinan treated patients as was found in the phase III study. 2) Using the life table analysis method, a higher rate of survival has been observed in the lentinan treated group, especially in combination with tegafur for gastric cancer, clearly showing such high survival rates as 12.97% (P less than 0.05) at two years after, and 9.51% (P less than 0.05) and 3.81%, at three and four years after respectively, and for colorectal cancer, 9.10% and 4.55% at two years and three years after, respectively.

Adult↗
PubMed1985

Monoclonal antibody-dependent murine macrophage-mediated cytotoxicity against human tumors is stimulated by lentinan.

The beta (1----3) glucan lentinan was tested for its capacity to increase the cytotoxic effect of murine peritoneal macrophages for human tumor cells in the presence of monoclonal antibodies (MAbs). Activity was maximum in macrophages obtained on day 5 following intraperitoneal injection of CBA mice with 2.5 mg of lentinan per kg body weight. Macrophages stimulated by lentinan were cytotoxic in conjunction with IgG1, IgG2a and IgG3 MAbs, but not with IgG2b, IgM, or IgA MAbs. The demonstration of a similar enhancing effect by lentinan on human macrophages might have implications for potentiating the tumoricidal effect of these macrophages in the presence of tumor antigen-specific MAbs.

Animals↗
PubMed1983

[Studies on the effect of lentinan on human immune system. II. In vivo effect on NK activity, MLR induced killer activity and PHA induced blastic response of lymphocytes in cancer patients].

Immunological activities of lymphocytes were studied in patients with cancer of digestive organs and mamma after administration of lentinan. When 11 cancer patients received lentinan i.v. 2 mg, NK activity of lymphocytes was increased in 4 patients on the following day. With the same condition, MLR induced killer activity against Raji cell of lymphocytes was increased in 3/7 patients and PHA response was also increased in 3/7 patients. These activities were returned to values before the administration of lentinan. Then each activity was examined after administration of lentinan twice a week. NK activity, MLR induced killer activity and PHA response were increased in 4/15, 8/12 and 5/11 patients, respectively.

Cytotoxicity, Immunologic↗
PubMed1983

[Antitumor effect of bacterial lipopolysaccharide (LPS) and a combination use of LPS and lentinan on C3H/He mice bearing MH-134 tumor].

Using C3H/He mice a series of experiments was carried to study the antitumor effect of lipopolysaccharide (LPS) in combined use with Lentinan extracted from Cortinellus shiitake and its influence on cellular immunity as well as antitumor effect of tumor necrosis factor (TNF) prepared from LPS, and the following results were obtained: 1) In the cases where LPS was administered when the tumor had grown to a certain extent after tumor transplantation, hemorrhagic necrosis of the tumor occurred within 48 hours, showing a high antitumor effect. 2) In the cases where LPS was used with Lentinan, i.e., 2 mg/kg/day of Lentinan was administered from the 1st to the 8th day after tumor transplantation, and 30 micrograms/kg of LPS given on the 12th day, the highest antitumor effect could be achieved. 3) By combined use of LPS and Lentinan delayed type hypersensitivity was intensified. 4) Upon application of rabbit serum containing TNF to cancer bearing mice, hemorrhagic necrosis of the tumor was observed within 48 hours, and a superior antitumor effect compared to LPS alone was noted in terms of tumor size and weight.

Animals↗
PubMed1982

Changes of antitumor immunity of hosts with murine mammary tumors regressed by lentinan: potentiation of antitumor delayed hypersensitivity reaction.

From 2 weeks after sc inoculation of MM46 mammary carcinoma cells into C3H/He mice, lentinan caused tumor regression, irrespective of its administration schedule (i.e., various doses and times of treatment, before and after tumor inoculation). The humoral and cellular immune responses of tumor-bearing mice with or without lentinan treatment were studied kinetically. From 2 weeks after tumor inoculation, antitumor antibodies (detected by macrophage-mediated or complement-dependent cytotoxicity assay) and LB (a serum protein) increased in tumor-bearing mice but the delayed-type hypersensitivity reaction against tumor (T-DHR) decreased. Lentinan restored and potentiated the T-DHR. The conditions under which lentinan is effective and the antitumor reactions responsible for tumor regression are discussed on the basis of these results.

Adjuvants, Immunologic↗