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 55 records · Page 3Linked to original sources
PubMedDate not supplied

Effects of oral lentinan on T-cell subsets in peripheral venous blood.

The effect of oral lentinan, a biological response modifier, on the control of systemic immune function was studied in six-week-old male Wistar-Imamichi specific-pathogen free rats. In the lentinan-treated group, 1 mg of lentinan dissolved in 1 ml of physiological saline was administered forcibly into the stomach twice weekly for four or eight weeks. Physiological saline alone was administered in a similar fashion to the control group. Leukocyte and lymphocyte counts were made and lymphocyte subsets measured using monoclonal antibodies W3/13, W3/25, and OX8, and a laser flow cytometry system. The T-cell level, the helper/inducer T-cell level, and the suppressor/cytotoxic T-cell level were measured. The peripheral leukocyte and lymphocyte counts did not change significantly in either group during treatment. After four weeks of treatment, however, the lentinan group had a significantly higher T-cell level, helper-cell level, and helper-suppressor ratio, and a significantly lower suppressor-cell level than did the control group. No significant between-group differences in the lymphocyte subsets or the helper-suppressor ratio were noted after eight weeks of treatment. Oral administration of lentinan appears to modulate the systemic immune function through stimulation of T cells, especially helper cells. Continued administration produced less effect, possibly due to a tolerance to the effect of lentinan.

Animals↗
PubMed1982

[Effect of lentinan administration of adrenalectomized rats and patients with breast cancer].

To investigate a clinical application of Lentinan, an immunomodulator and polysaccharide extracted from Lentinus edodes, an effect of Lentinan on the adrenalectomized rats was examined. The multiple injection of Lentinan did not result in any changes in the growth curves, survival rate nor histamine sensitivity, compared with those of the controls, indicating that Lentinan might be a useful agent in the combination therapy of adrenalectomized animals. The clinical safety of Lentinan administration for the patients with advanced or recurrent breast cancer who received bilateral oophorectomy and adrenalectomy were confirmed, and its efficacies were evaluated by prolongation of life span and antitumor effect. The improvement of prognosis was observed in Lentinan treated patients, compared with the control.

Adrenalectomy↗
PubMed1996

Improvement of erythroid toxicity by lentinan and erythropoietin in mice treated with chemotherapeutic agents.

Lentinan, an antitumor polysaccharide, has been assessed for its potential in vivo to augment erythroid progenitor cells and protect them from the cytotoxic effects of antitumor chemotherapeutics. Lentinan augmented the level of burst-forming units-erythroid (BFU-E) and accelerated the recovery of the reduced number of BFU-E in mice treated with 5-fluorouracil (5-FU); lentinan did not influence red blood cell counts or colony-forming unit-erythroid (CFU-E) numbers in the femoral marrow. A significant decrease in stem cell inhibitory factor (SCIF) activities in bone marrow and an increase in colony-forming unit-spleen (CFU-S) formation were observed in the lentinan-treated mice. The mechanism of augmented BFU-E formation may be partly due to augmented production of stem cells, giving rise to both CFU-GM and BFU-E. Furthermore, when lentinan administration was followed by administration of erythropoietin (Epo) in 5-FU-treated mice, increases in femoral marrow and splenic CFU-E formation and augmentation of reticulocyte counts were observed beyond the level observed in mice treated with Epo alone. These results suggest that lentinan may augment the effects of Epo on erythropoiesis in the course of anemia and the decreased erythropoiesis in cancer patients receiving chemotherapy.

Animals↗
PubMedDate not supplied

Lentinan potentiates immunity and prolongs the survival time of some patients.

For the selection of patients responding well to lentinan, we performed two immunological analysis of patients. Flow cytometric analysis was obtained from peripheral blood lymphocytes; the patients who had greater than 2.5 ratio of [CD11(-) CD8(+)/CD11(+) CD8(+) after treatment]/[CD11(-) CD8(+)/CD11(+) CD8(+) before treatment] at 10 days after lentinan administration showed prolonged survival. The analysis of the- levels of soluble factors such as IL-6, sIL-6R, TNF-alpha, G-CSF, sICAM-1, IAP, and PGE2 and the decreasing levels of G-CSF, IL-6, and PGE2 after lentinan administration had a statistically significant correlation with the ratio of [CD4(+) CD29(+)/CD4(+) CD29(-) after treatment]/[(CD4(+) CD29(+)/CD4(+)CD29(-) before treatment]. The decrease in IL-6, G-CSF, and PGE2 levels after lentinan administration indicated an increase in immunine potential. From these results, we belive that patients with over 2.5-fold increase in [CD11(-) CD8(+)/CD11(+) CD8(+) after treatment]/[CD11(-) CD8(+)/CD11(+) CD8(+) before treatment] and showing a decrease in IL-6, G-CSF, and PGE2 levels after lentinan administration should continue treatment with lentinan for a long period.

Adjuvants, Immunologic↗
PubMed2004

Morphologies and conformation transition of lentinan in aqueous NaOH solution.

Molecular morphologies and conformation transition of lentinan, a beta-(1-->3)-D-glucan from Lentinus edodes, were studied in aqueous NaOH solution by atomic force microscopy (AFM), viscometry, multiangle laser light scattering, and optical rotation measurements. The results revealed that lentinan exists as triple-helical chains and as single random-coil chains at NaOH concentration lower than 0.05M and higher than 0.08M, respectively. Moreover, the dramatic changes in weight-average molecular weight Mw, radius of gyration [s2](1/2), intrinsic viscosity [eta], as well as specific optical rotation at 589 nm [alpha]589 occurred in a narrow range of NaOH concentration between 0.05 and 0.08M NaOH, indicating that the helix-coil conformation transition of lentinan was carried out more easily than that of native schizophyllan and scleroglucan, and was irreversible. For the first time, we confirmed that the denatured lentinan molecule, which was dissolved in 0.15M NaOH to be disrupted into single coil chains, could be renatured as triple helical chain by dialyzing against abundant water in the regenerated cellulose tube at ambient temperature (15 degrees C). In view of the AFM image, lentinan in aqueous solution exhibited the linear, circular, and branched species of triple helix compared with native linear schizophyllan or scleroglucan.

Lasers↗
PubMed1994

Curative effects of combination therapy with lentinan and interleukin-2 against established murine tumors, and the role of CD8-positive T cells.

The antitumor activity of a combination of an antitumor polysaccharide, lentinan (a beta 1-3 glucan with beta 1-6 branches), and interleukin-2 (IL-2) was evaluated against established MBL-2 lymphoma and S908.D2 sarcoma at i.d. sites. Treatment of the MBL-2-tumor-bearing BDF1 mice with lentinan and IL-2 induced complete regression of tumor in 87.5% of mice treated. In contrast, treatments using either lentinan or IL-2 alone failed to induce complete regression of tumor, although temporal growth inhibition of tumor was observed about in half of the mice treated. Improvements of antitumor effects by the combination of lentinan and IL-2 were also observed in the MBL-2/B6 and S908.D2/B10.D2 systems. Expression of the antitumor effects of lentinan/IL-2 treatments required the intact T cell compartment, because the effects were not observed when nude mice were used. In the MBL-2/B6 system, the antitumor action of lentinan/IL-2 treatment was abolished in mice treated with antibody to CD8 antigen, whereas antibodies to CD4 or NK1.1 were ineffective. Furthermore, augmented tumor-specific cytotoxic T lymphocyte (CTL) activity was observed in regional lymph node cells of the mice after lentinan and IL-2 administration. These data indicate that the antitumor effects of lentinan/IL-2 are mediated by CD8+ CTL but not by CD4+ T cells or NK1.1+ NK/LAK cells, and suggest that this combined therapy may be effective against even established tumors that are resistant to IL-2 therapy.

Animals↗
PubMed1984

Acting mechanisms of Lentinan in human--I. Augmentation of DNA synthesis and immunoglobulin production of peripheral mononuclear cells.

The immunopotentiating activity and acting mechanisms of Lentinan were investigated in the human system, resulting in clarification of the following characteristics. (a) Augmentation of DNA synthesis of peripheral mononuclear cells (PMNC) occurred both in vitro and in vivo by adding or injecting Lentinan, for which the coexistence of T cells, B cells and adherent cells (mainly monocytes) was essential. (b) No additional mitogenic effect of Lentinan was observed when PMNC were incubated with both Lentinan and other mitogens. (c) In vitro production of immunoglobulin by PMNC induced with pokeweed mitogen was enhanced through the inhibition of suppressor T cell activity by Lentinan.

Adjuvants, Immunologic↗
PubMed1988

Regression induced by lentinan, of peritoneal carcinomatoses in a model of colon cancer in rat.

Lentinan has been tested in a model of colon cancer in rats. Peritoneal carcinomatoses were induced in BDIX rats by i.p. injections of syngeneic cells isolated from a colon carcinoma, and established in a permanent cell line. The treatment consisted of five i.p. injections, 2 days apart, of 2 mg lentinan/kg at a concentration of 200 micrograms/ml. This was started on day 14 after tumor cell injection, when the rats bore numerous nodules of 1-5 mm. Lentinan significantly inhibited the growth of carcinomatoses. Eleven out of the 20 rats treated with the best lentinan therapy were tumor free at autopsy on day 42. Lentinan significantly increased the life span of carcinomatous rats. The half life following tumor cell injection was 42 days in the control and 70 days in the treated group. Four out of 10 treated rats were still alive on day 210. They were tumor free at autopsy, whereas all the controls died between the 40th and the 70th day. The effectiveness of lentinan was dependent on the number and frequency of the injections. A dose effect was obtained and a strong influence of the concentration was shown.

Animals↗
PubMed1990

Induction of endogenous lymphokine-activated killer activity by combined administration of lentinan and interleukin 2.

Lymphokine-activated killer activity in vivo (endogenous LAK activity) was found to be augmented by combined administration of lentinan, a beta (1-3) glucan with beta-1,6 branches, and interleukin 2 (IL-2). In contrast, addition of lentinan during culture in vitro did not augment LAK activity induced by IL-2. Surface marker analysis of endogenous LAK cells revealed that endogenous LAK cells induced by a combined administration of lentinan and IL-2 were all NK-type LAK cells, which express asialo-GM1 and lack T3, Thy-1 and Lyt2, whereas LAK cells generated in vitro were composed of both NK-type LAK and T-type LAK cells, which express T3 and Thy-1, and lack asialo-GM1. Furthermore, combined administration of lentinan and IL-2 was found to augment the endogenous LAK activity even in the tumor bearer, and show a substantial inhibition of tumor growth and a significant increase in survival rate in the C3H/HeN/MM46 system. Results of the present investigation offer a possible clinical application of a combination of lentinan and IL-2 for immunotherapy against cancer without detrimental side effects.

Animals↗
PubMedDate not supplied

Strain differences in the cytotoxic activity and TNF production of murine macrophages stimulated by lentinan.

The effect of lentinan, a glucan type immunomodulatory polysaccharide was studied on the antitumor cytotoxicity and on the TNF secretion of peritoneal macrophages in inbred H-2 congeneic mouse strains under in vivo and in vitro conditions. The cytotoxic activity and TNF secretion of murine macrophages was found to be elevated by lentinan in vitro and in vivo conditions. The effectiveness of lentinan to induce cytotoxicity and TNF secretion was highly influenced by the genotype of the host. The increased cytotoxicity of macrophages was modified by the H-2 and the background genes. The black background and the H-2a and H-2d haplotypes were associated with high responsiveness, while the albino and agouti background and the H-2b and the H-2k haplotypes with low responsiveness to lentinan treatment. The degree of TNF secretion of macrophages stimulated by lentinan was influenced by the H-2 genes only. Similarly, to the macrophage cytotoxicity the TNF secretion in the H-2a and H-2d haplotypes were found to be high, on the other hand, in the H-2b and H-2k were low.

Animals↗
PubMed1999

The preoperative administration of lentinan ameliorated the impairment of natural killer activity after cardiopulmonary bypass.

The aim of this study was to determine whether the preoperative administration of lentinan, which is used clinically to activate T cell function in cancer patients, prevents the impairment of lymphocyte function after cardiopulmonary bypass (CPB). A total of 25 adults undergoing coronary artery bypass grafting were enrolled in this study. Lentinan (2 mg) was given to 10 randomly selected patients 7 d before surgery, while the other 15 patients were considered as a control. The white blood cell count, percentage of lymphocytes, subsets of lymphocytes, and natural killer cell activity were measured preoperatively, immediately after CPB and 1, 3, and 6 d after surgery. The white blood cell counts and the percentage of lymphocytes were not significantly different between the two groups; however, the percentage of CD4-positive cells in the lentinan group recovered to normal more rapidly than in the control group. Although natural killer cell activity was impaired in the control group after CPB, it maintained a nearly normal level in the lentinan group. The preoperative administration of lentinan for patients undergoing CPB ameliorated the impairment of natural killer activity and promoted the rapid recovery of CD4-positive cells.

Adjuvants, Immunologic↗
PubMedDate not supplied

Collapse and association of denatured lentinan in water/dimethlysulfoxide solutions.

Triple helical lentinan, beta-(1-->3)-D-glucan from Lentinus edodes, was denatured in dimethlysulfoxide (DMSO) into single random coils. The DMSO solutions of randomly coiled lentinan were diluted with pure water to different wH (the weight fraction of water in the mixed solvent), and their specific optical rotation [alpha]D, reduced viscosity (lnetar)/c, and hydrodynamic radius Rh were investigated as a function of wH and storage time t. With an increase of wH from 0.1 to 0.2, [alpha]D increased sharply, suggesting that transition of conformation of the macromolecules has occurred. When wH was lower than 0.1, (lnetar)/c of lentinan in water-diluted DMSO exhibited the almost same value as that in pure DMSO and changed hardly with increasing t. Interestingly, (lnetar)/c decreased to reach a minimum with a further increase of wH from 0.1 to 0.25 and then increased with a continuous increase of wH from 0.25 to 0.5. Both (lnetar)/c and Rh of the denatured lentinan in water-diluted DMSO with wH of approximately 0.25 both exhibited a minimum, indicating that collapsed coil chains have occurred. All of the experimental findings revealed that the behaviors of lentinan in water-diluted DMSO solution with wH < 0.1 were consistent with that in good solvent, DMSO. When wH = 0.25, the quality of the mixed solvents became worse, and the dominant intramacromolecular hydrogen-bond interaction enhanced, leading to minimum of viscosity and size of the chains as a result of the collapsed coils. When wH > 0.25, the quality of the mixture weakens further, and the intermolecular hydrogen-bond interaction enhanced and was dominant, leading to aggregation of the collapsed chains.

Dimethyl Sulfoxide↗
PubMed1994

Synergistic antimetastatic effects of lentinan and interleukin 2 with pre- and post-operative treatments.

The antimetastatic activity of a combination of lentinan and interleukin 2 (IL-2) was evaluated against spontaneously metastatic 3-methylcholanthrene-induced DBA/2.MC.CS.T fibrosarcoma. Although pre-operative treatment with either IL-2 or lentinan alone exerted little effect on the reduction of lung metastasis colony numbers (7.1% or 28.4% reduction, respectively), the combination exhibited a synergistic effect (85% reduction). Furthermore, 3 of 13 mice given the pre-operative combination treatment achieved complete cure, while no mice given saline did. Although the post-operative combination treatment also reduced the colony number (71% reduction), it caused little prolongation of survival and no mouse achieved complete cure. Synergistic effects were observed between pre- and post-operative treatments with lentinan and IL-2: 8 of 12 mice were completely cured. The anti-metastatic activity was abolished in mice treated simultaneously with antibodies to CD4 and CD8 antigens, whereas either CD4, CD8, or NK1.1 antibody alone was ineffective. Analysis of the cellular mechanism involved in the antimetastatic activity revealed the involvement of a tumor-associated antigen-specific delayed-type hypersensitivity response. These data suggest that the life-prolonging effect of the combination of lentinan and IL-2 is mediated by antigen-specific T cells and that the combination of pre- and post-operative therapy with lentinan and IL-2 may be effective to prevent cancer recurrence and metastasis after surgical resection.

Animals↗
PubMed1980

[Acute toxicity of lentinan in mice and rats (author's transl)].

A new anti-tumor polysaccharide, lentinan (beta-1, 3 Glucan) was studied on the acute toxicities using both sexes of mice (ICR) and rats (CD) treated by intravenously (i.v.) intraperitoneally (i.p.), subcutaneously (s.c.) and orally (p.o). LD50 values in mg/kg body weight were essentially the same regardless of species as well as sexes and estimated as follows: 250-500 (i.v.) greater than 2500 (i.p., s.c., and p.o.). Cyanosis, convulsion and death were observed in both species of animals administered (i.v.) with only higher dosages of lentinan. No remarkable toxic signs being specific from lentinan were observed in any cases of treatment, i.p., s.c., and p.o. Gross findings: enlargement of the spleen (i.v., i.p., s.c.) and coarse nodular surface of the kidney (i.v.) in the both species of animals, erythema of the ears (i.v., i.p., s.c.) in mice, mesenteric petechial hemorrhage of the lung and abdomen (i.v.) enlargement of the mesenteric lymph nodes (i.v.) and edema of the diaphragm and intestine (i.p.) in rats were observed. In parallel, another sample of lentinan for clinical use prepared by freeze-dried procedure was tested in both sexes of mice and rats treated by i.v. alone, comparing with a original sample mentioned above. So far as the acute toxicities of lentinans concerned, no significant differences between two preparations were observed.

Animals↗
PubMedDate not supplied

Effects of lentinan on colorectal carcinogenesis in mice with ulcerative colitis.

Lentinan; i.e., polysaccharides extracted from a kind of black mushroom shiitake, has been clinically applied as an antitumor and antimetastatic drug, and has been reported to prevent both chemical and viral carcinogenesis. It is known that lentinan affects the tumorous vascular system resulting in the induction of hemorrhagic necrosis which is dependent on T-cells in the tumor. Repeated mucosal necrosis-regeneration sequence in chronic ulcerative colitis induced with 3% dextran sulfate sodium led to colorectal carcinogenesis in azoxymethane-pretreated mice. In the present study, the additive treatment with lentinan in the azoxymethane-dextran sulfate sodium treated mice enhanced the colorectal high-grade dysplasia, though not significantly, and the splenic weight. This may show the proliferation of pathogenic splenic T cells resulting in a change for the worse of ulcerative colitis, anemia induced with hemorrhage and colorectal carcinogenesis; i.e., high-grade dysplasia of the mucosa and/or invasive adenocarcinomas of the colorectum. The present results may recommend chemoimmunotherapy while using lentinan, but not immunotherapy using lentinan alone, is indicated for the management of cancer patients.

Animals↗
PubMed2005

Intranasal application of lentinan enhances bactericidal activity of rat alveolar macrophages against Mycobacterium tuberculosis.

To study the in vivo interaction between lentinan-stimulated alveolar macrophages and Mycobacterium tuberculosis were used rats intranasally infected with 2 x 10(8) CFU. Before infection animals were treated intranasally with lentinan at a dose of 1 mg/kg (administrated three times at 2 days periods). Samples of broncho-alveolar lavage fluid were obtained from rats at different intervals -3, 24 and 72 h after infection. The process of phagocytosis in vivo was observed by light and electron microscopy, as well as acid phosphatase cytochemistry methods. Bactericidal activity of alveolar macrophages following the same intranasal installation of lentinan was assessed by in vitro "killing" ability test against M. tuberculosis. Nitrite production by lentinan activated alveolar macrophages was measured 24 h after ex vivo culture of these cells. It was demonstrated that lentinan induces high level of alveolar macrophage activation manifested through enhanced bactericidal effect against M. tuberculosis, which correlates with the induction of reactive nitrogen intermediates, increased activity of lysosomal enzymes (acid phosphatase), and with effective phagolysosomal fusion followed by destruction of Mycobacteria.

Acid Phosphatase↗
PubMed2005

[Anticancer immunotherapy with perorally effective lentinan].

Lentinan is a beta(1-3) glucan clarified to have a life prolonging effect in non-operable, recurrent gastric cancer patients in combination with chemotherapy. The long lasting issue remaining to be resolved has been the ineffectiveness of Lentinan when administered per-orally. Beta(1-3) glucans possess the particulate size around 100-200 microm in aqueous solution which dampered the absorption through abdominal mucosa. Subsequently the particulate size of Lentinan impaired the immunostimulating potency, to induce reductive form of antigen presenting cells, macrophages and dendritic cells relevant for the polarization of Th1/Th2 balance to Th1. The situation is also the case for the clinical benefit of lentinan to reduce the side effect of chemotherapeutic agents such as TS-1, Gemzar, CDDP, known to be a critical dose limiting factor of these agents and to improve quality of life of the patients. Using the modern nano-technology procedures, Mitherapist, containing 15 mg/dl Lentinan, with a particulate size of 0.2 microm able to pass through mucosal barrier was provided. It was found in randomized double blind clinical testing that Mitherapist is effective against allergy by reducing an antigen specific IgE level through polarization to Th1 biased immune response even by per-oral administration. Per oral administration also exhibited the reduced side effect of chemotherapeutic agents such as TS-1, Gemzar, CDDP and greatly improved quality of life of the cancer patients. The role of hypoxia in local neoplastic tissues will be also discussed.

Adjuvants, Immunologic↗
PubMed1990

[Antigenic phenotype of the lymphocytic component of regional lymph nodes in patients with cervical cancer and its modulation by lentinan].

Immunohistochemical study with various monoclonal antibodies to the mononuclear cell surface antigens was carried out on the regional lymph nodes in patients with cervical cancer to assess the augmentative effect of lentinan. Zero, 2, 4, or 6 mg of lentinan was administered i.v. one day prior to surgery to patients with cervical cancer (14 cases with FIGO stage 0 and 19 with FIGO stage Ib) and those with benign gynecologic tumors (8 cases with myoma uteri and 6 with ovarian tumor). Frozen sections of fresh pelvic lymph nodes obtained from these patients during surgery were stained by the ABC (avidin-biotin-peroxidase complex) method using several monoclonal antibodies to define the surface phenotype of mononuclear cells. The results were as follows: 1. Pelvic lymph nodes in patients with benign disease: In the absence of lentinan, lymphocytes stained with Leu 3a antibody were more numerous than those stained with Leu 2a, and both were observed mainly in the paracortical area (PC). The number of lymphocytes stained with Leu 4 antibody was practically equal to the sum of those stained with Leu 3a and Leu 2a. HLA-Dr positive lymphocytes were present in moderate numbers in PC and sinus. The above findings were not changed by the administration of lentinan. Cells stained with monoclonal antibodies including Leu 7, 11, M3, and IL-2 receptor (IL-2R) were very few or absent. 2. Pelvic lymph nodes in patients with cervical cancer receiving no lentinan: The findings obtained in these cases were much the same as those in patients with benign tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Differentiation↗