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An Evidence-based Perspective of Lentinus Edodes (Shiitake Mushroom) for Cancer Patients
Abstract
Lentinus edodes, known as shiitake mushroom in Japan and Xiang Gu or fragrant mushroom in China, is an edible mushroom that is commonly cultivated
worldwide. This mushroom has been consumed for centuries as a delicacy and for its beneficial effects on human health. Early
in the fourteenth century, the Chinese physician Wu Rui recorded that shiitake was beneficial for the treatment of various
forms of malignancy. Since 1969, groundbreaking investigations have performed in this subject, and a large number of high
quality scientific studies have demonstrated the immunomodulatory, antitumor, antiviral, and cholesterol-regulating effects
of this mushroom. In addition, the use of shiitake in combination with chemotherapy and radiotherapy has reported in Japan.
Since cancer is a leading cause of death worldwide and it is exceptionally difficult to cure malignant tumors, cancer prevention
may be a more effective strategy to control and ultimately overcome cancer. Here, we will summarize the antitumor activity
and immunomodulating action of biologically active polysaccharides, mostly β-glucans, from shiitake mushroom fruit bodies
and/or cultured mycelium based on experimental and clinical findings. The following aspects of shiitake mushroom in relation
to cancer would be discussed: mechanisms of action, optimal dosage, and timing of administration for clinical use of its antitumor
and immunostimulating properties, prospective use in clinical therapy, clinical safety, and possible adverse effects.
... 58 Activated receptor works as antigen-presenting cells (APC) and activates CD4 + and CD8 + T cells to produce pro-inflammatory cytokines such as tumor necrosis factor (TNF) α, anti-tumor cytokine interferon γ (IFN γ), granzyme B and perforin, leading to tumoricidal activity. 30 Activated dectin-1 further leads to the conversion of normal immunosuppressive M2 macrophages into M1 macrophages. This switching leads to the activation of M1 macrophages resulting in the activation of Th-1 type T-cells. ...
The global increase in cancer cases, particularly prostate cancer, poses a significant health challenge worldwide. Conventional treatments such as surgery, radiation therapy, hormone therapy, chemotherapy, and immunotherapy offer valuable options but are associated with limitations and potential side effects. As a result, there is growing interest in complementary therapies, including natural compounds such as β-glucans, derived from sources such as yeast and mushrooms. In this review, we explored the potential therapeutic role of medicinal mushrooms β-glucan in prostate cancer treatment. β-glucans has demonstrated anti-cancer properties in preclinical studies, including inhibition of proliferation, induction of apoptosis, and modulation of immune responses. Studies in prostate cancer cell lines and animal models have shown promising results, with β-glucan inhibiting tumor growth, inducing DNA damage, and regulating tumor markers such as p53 and prostate specific antigen. β-glucans acts through various pathways, including stimulation of dendritic cells, modulation of cytokine secretion, suppression of myeloid-derived suppressor cells, and enhancement of immune responses. Moreover, β-glucans exhibits anti-androgenic and immune-modulatory effects, making it a promising candidate for prostate cancer treatment. In this study, we also focused on the mechanism of action of β-glucans through various pathways including tumor cell death by oxidative stress created through ROS generation and autophagy. Although preclinical studies support the potential therapeutic efficacy of medicinal mushrooms β-glucans, further research is needed to elucidate its clinical utility and safety in human trials.
... Regarding clinical studies of antitumor activity and immunomodulating action of biologically active metabolites, mostly polysaccharides (β-glucans) from mushroom fruit bodies and/or cultured mycelium, lentinan from L. edodes, schizophyllan from S. commune, MD-fraction from G. frondosa, and compounds from T. versicolor (PSK and PSP) have been in clinical use, especially in Japan and China, for the adjuvant tumor therapy (immunotherapy) in addition to the major cancer therapies like surgical operation, radiotherapy, and chemotherapy (Lindequist et al. 2005). Among mushrooms, L. edodes (shiitake) has been studied most extensively (antitumor and immunostimulating properties revised by Shen et al. (2011), while epidemiological evidence has shown a correlation between daily mushroom consumption and a low rate of cancer mortality in Japan. Application of lentinan (parenteral) in addition to chemotherapy led to prolongation of survival time, restoration of immunological parameters, and improvement of life quality in patients with stomach cancer, colon cancer, and other carcinomas in comparison to patients who had chemotherapy alone (Lindequist et al. 2005). ...
Mouse leukocyte CR3 (Mac-1, αMβ2 integrin) was shown to function as a receptor for β-glucans in the same way as human CR3. Soluble zymosan polysaccharide (SZP) or pure β-glucans labeled with FITC or 125I bound in a saturable and reversible manner to neutrophils, macrophages, and NK cells. This lectin activity was blocked by anti-CD11b mAb M1/70 or 5C6 and did not occur with leukocytes from CR3−/− (CD11b-deficient) mice. SZP preparations containing primarily mannose or glucose bound to CR3, and the binding of 125I-labeled β-glucan to CR3 was competitively inhibited by β-glucans from barley or seaweed, but not by yeast α-mannan. Also, as with human CR3, the lectin site of mouse CR3 was inhibited by α- or β-methylglucoside (but not d-glucose), α- or β-methylmannoside, and N-acetyl-d-glucosamine. Phagocytosis of zymosan and serum-opsonized zymosan was partially inhibited by anti-CR3 and was reduced to <40% of normal with leukocytes from CR3−/− mice. As with neutrophils from patients with CD18 deficiency, neutrophils from CR3−/− mice exhibited no phagocytosis of particulate β-glucan. SZP or β-glucans primed CR3 of neutrophils, macrophages, and NK cells for cytotoxicity of iC3b-opsonized tumor cells that otherwise did not trigger killing. β-Glucan priming for cytotoxicity was inhibited by anti-CR3 and did not occur with leukocytes from CR3−/− mice. The primed state of macrophage and NK cell CR3 remained detectable for 18 to 24 h after pulsing with β-glucans. The similarity of mouse and human CR3 in response to β-glucans highlights the utility of mouse tumor models for development of therapeutic β-glucans.
β-Glucans were identified 36 years ago as a biologic response modifier that stimulated tumor rejection. In vitro studies have shown that β-glucans bind to a lectin domain within complement receptor type 3 (CR3; known also as Mac-1, CD11b/CD18, or αMβ2-integrin, that functions as an adhesion molecule and a receptor for factor I-cleaved C3b, i.e., iC3b) resulting in the priming of this iC3b receptor for cytotoxicity of iC3b-opsonized target cells. This investigation explored mechanisms of tumor therapy with soluble β-glucan in mice. Normal mouse sera were shown to contain low levels of Abs reactive with syngeneic or allogeneic tumor lines that activated complement, depositing C3 onto tumors. Implanted tumors became coated with IgM, IgG, and C3, and the absent C3 deposition on tumors in SCID mice was reconstituted with IgM or IgG isolated from normal sera. Therapy of mice with glucan- or mannan-rich soluble polysaccharides exhibiting high affinity for CR3 caused a 57–90% reduction in tumor weight. In young mice with lower levels of tumor-reactive Abs, the effectiveness of β-glucan was enhanced by administration of a tumor-specific mAb, and in SCID mice, an absent response to β-glucan was reconstituted with normal IgM or IgG. The requirement for C3 on tumors and CR3 on leukocytes was highlighted by therapy failures in C3- or CR3-deficient mice. Thus, the tumoricidal function of CR3-binding polysaccharides such as β-glucan in vivo is defined by natural and elicited Abs that direct iC3b deposition onto neoplastic cells, making them targets for circulating leukocytes bearing polysaccharide-primed CR3. Therapy fails when tumors lack iC3b, but can be restored by tumor-specific Abs that deposit iC3b onto the tumors.
Activated human monocytes produce a monokine, interleukin-1 (IL-1) which can amplify the immune response by inducing antigen specific T cells to elaborate T cell growth factor, or interleukin-2, which in turn causes T cells to proliferate. The immune adjuvant lentinan has been shown in this study to augment IL-1 production by human monocytes. Stimulation of IL-1 by lentinan was seen as early as 5 hr, with some effect as late as 60 hr. Optimal effects were seen with very low concentrations, around 0.1 μg/ml. Lentinan was also able to stimulate IL-1 production by the leukemic cell line, K-562. The data reported here suggest that the previously reported adjuvant effects of lentinan may in part be mediated via its ability to stimulate IL-1 production.
DNA vaccination can induce specific CD8(+) T cell immune response, but the response level is low in large mammals and human beings. Coadministration of an adjuvant can optimize protective immunity elicited by a DNA vaccine. In this study, we investigated the effect of a synthetic glucohexaose (beta-glu6), an analogue of Lentinan basic unit, on specific CD8(+) T cell response induced by a DNA vaccine encoding HBcAg (pB144) in mice. We found that beta-glu6 promoted the recruitment and maturation of dendritic cells, enhanced the activation of CD8(+) and CD4(+) T cells and increased the number of specific CD8(+)/IFN-gamma(+) T cells in lymphoid and nonlymphoid tissues in mice immunized by pB144. Immunization with pB144 and beta-glu6 increased the anti-HBc IgG and IgG2a antibody titer. These results demonstrate that beta-glu6 can enhance the virus-specific CTL and Th1 responses induced by DNA vaccine, suggesting beta-glu6 as a candidate adjuvant in DNA vaccination.
Lentinan, a beta-glucan nutritional supplement isolated from the shitake mushroom (Lentula edodes), is a biological response modifier with immunostimulatory properties. Concomitantly, the role of beta-glucans as chemoimmunotherapeutic in a number of solid cancers has been widely documented. We investigated the effects of nutritional grade lentinan upon BN rats and in a preclinical syngeneic model of acute myeloid leukemia. BN rats supplemented daily with lentinan exhibited weight gains, increased white blood cells, monocytes, and circulating cytotoxic T-cells; and had a reduction in anti-inflammatory cytokines IL-4, IL-10, and additionally IL-6. Lentinan treatment of BN rats with BNML leukemia resulted in improved cage-side health and reduced cachexia in the terminal stage of this aggressive disease. Combination of lentinan with standards of care in acute myeloid leukemia, idarubicin, and cytarabine increased average survival compared with monotherapy and reduced cachexia. These results indicate that nutritional supplementation of cancer patients with lentinan should be further investigated.
Lentinan (LNT) is an immune adjuvant medicine for advanced gastric cancer in Japan. Recently, an oral formulation of superfine dispersed lentinan (SDL) has become clinically available. To investigate the safety and effectiveness of SDL, a multi center clinical study in patients with advanced colorectal cancer was conducted.
Adverse events were assessed and the patients' quality of life (QOL) and the binding ability of peripheral blood monocytes (PBM) to LNT were also evaluated.
Four grade 2 adverse events associated with SDL treatment were observed among the 80 patients. Adverse events associated with chemotherapy were observed in 9 out of the 64 chemotherapy-treated patients. Among the 48 patients assessed for QOL, the patients with low QOL scores before SDL treatment (n=23) reported a significant improvement in their QOL scores after 12 weeks of SDL administration. The rates of LNT-binding PBM in the QOL-improved group were significantly higher than those in the QOL-not-improved group (p<0.05).
SDL was safe and effective for suppressing the adverse effects of chemotherapy as well as improving QOL. The binding ability of PBM to LNT appears to be a promising predictor of QOL improvement after SDL administration.
Recently, complementary alternative medicine is actively performed for cancer therapy. Superfine dispersed lentinan (beta-1,3-glucan)--an oral effective form--was recently developed and available. We investigated the effectiveness of superfine dispersed lentinan in advanced pancreatic cancer patients in a multi-center study.
Twenty-nine patients with unresectable and recurrent pancreatic cancer were enrolled, and adverse events and quality of life scores were assessed. Survival times were evaluated according to results of a 3-year follow-up survey.
Although a diarrhea of grade-1 adverse event dependent on the test article (3.4%) was observed, the symptom was remitted without any treatment. This indicates that test article was free of anything harmful. Median survival time was 12.1 months (95% confidence interval: 7.3-25.7 months) in 25 eligible patients. Five (20%) out of 25 patients were alive for 3 years. There was a significant correlation between the quality of life scores after the superfine dispersed lentinan treatment and survival times.
A superfine dispersed lentinan is deemed safe and effective for advanced pancreatic patients' survival and improvement of quality of life. And the assessment of quality of life status after the administration of superfine dispersed lentinan is a promising prognostic predictor.
Purpose: In vitro beta-glucan can enhance tumor cytotoxicity through iC3b receptors on leukocytes. We tested if (1-->3),(1-->4)-beta-D-glucan (beta-glucan) can synergize with anti-GD2 monoclonal antibody (MoAb) 3F8 (mouse IgG3) in therapy of human neuroblastoma xenografts. Experimental Design: Athymic nude mice with established neuroblastoma xenografts were treated with daily i.p. or p.o. beta-glucan, in the presence/absence of i.v. MoAb twice a week, for 22-29 days. Serial tumor volumes and body weights were monitored. Results: 3F8 plus beta-glucan produced near-complete tumor regression/disease stabilization, whereas 3F8 or beta-glucan alone did not significantly affect tumor growth. For NMB7 tumors, median survival of 3178 plus beta-glucan group was 5.5-fold that of control groups (P < 0.001), and for LAN-1, the survival difference was 2.6-fold. Forty-seven percent of the mice with NMB7 and 18% with LAN-1 remained progression free in contrast to <3% of controls. Antitumor effect was seen at greater than or equal to40 mug of glucan dose, i.v. or p.o., and in all human neuroblastoma cell lines tested. No toxicities were noted in mice treated with either beta-glucan alone or 3F8 plus beta-glucan (4-4000 mug/dose). In contrast to anti-GD2 MoAb 3G6 (IgM), 3F8 F(ab')(2) and MoAb 8H9 (IgG1) did not activate complement and had no synergy with beta-glucan. Antitumor effect of 3F8 plus p.o. beta-glucan persisted after antiasialo-GM1 antibody treatment, as we as in NK-deficient host. Conclusions: p.o. 1,3-1,4-beta-glucan synergized with antitumor IgG and IgM MoAb in vivo. Because beta-glucan was well tolerated and inexpensive, its potential value in cancer therapy deserves further investigation.
The carbohydrate polymers known as β-1,3-D-glucans exert potent
effects on the immune system - stimulating antitumour and antimicrobial
activity, for example - by binding to receptors on macrophages and other
white blood cells and activating them. Although β-glucans are known
to bind to receptors, such as complement receptor 3 (ref. 1), there is
evidence that another β-glucan receptor is present on macrophages.
Here we identify this unknown receptor as dectin-1 (ref. 2), a finding
that provides new insights into the innate immune recognition of
β-glucans.
Lentinus edodes (Berk.) Sing., known historically in Japan as shiitake and in China as xiang gu, or "fragrant mushroom," is the second most commonly cultivated edible mushroom worldwide. Shiitake is an important ingredient in Chinese and Japanese cuisine, and is increasingly finding its way onto the tables of North Americans, Europeans, and other cultures. The health benefits of shiitake are not so widely known, but the number and quality of scientific studies are rapidly increasing, demonstrating its immune-modulating, antitumor, antiviral, and cholesterol-regulating effects. In North America, one out of three people will have cancer sometime in his or her life. Cancer is the second leading cause of death in technologically developed countries worldwide, and the proven protective effect and use in Japan of shiitake in combination with chemo- and radiation therapy may well increase its production and popularity over the next few years. While some excellent research has come out of Japan in the last 15 years, sparking international interest in the medicinal effects of shiitake, few controlled studies with humans exist. More randomized, double-blind, controlled studies need to be funded and carried out to clarify the benefits, dose, and therapeutic regimens for the use of shiitake in cancer and other diseases. Based on the existing literature, cooked shiitake fruiting bodies, powdered fruiting bodies and mycelium, and purified extracts seem to be extremely safe.
The structure and conformation of lentinan, an anti-tumor, branched (1→3)-β-d-glucan from Lentinus edodes, and its acid-degraded, lower molecular-weight fractions have been investigated by 13C-n.m.r. spectroscopy. It is found that their 13C-n.m.r. spectra are considerably changed, depending on the molecular weight. The conformational behavior as studied by 13C-n.m.r. spectroscopy is consistent with that revealed by a study of the shift in the absorption maximum of Congo Red complexed with lentinan and its acid-degraded fractions. It is found that the water-soluble fraction II (mol. wt. 3,640) gives rise to well-resolved 13C-n.m.r. spectra; the 13C-signals are assigned to (1→3)-β-d-glucan and branch points at C-6. The branched structure is also confirmed by examination of the 13C-n.m.r. spectra of the compounds in dimethyl sulfoxide. For the gel state of the fractions of higher molecular-weight, lentinan (mol. wt. 1,000,000) and fraction IV (mol. wt. 16,200), however, 13C-n.m.r. spectra of considerably attenuated signal-amplitude are observed. The fact that the 13C-signals of the β-d-(1→3)-linked main chain and side chains are completely suppressed is explained as a result of immobilization caused by their taking an ordered conformation. The 13C-resonances observed in the gel state, which are assigned to β-d-(1→6)-linkages, are unequivocally assigned to the side chains (of disordered conformation). Finally, the ordered conformation of both the β-d-(1→3)-linked main chain and side chains is identified as the single-helix conformation, which tends to form multiple helixes as junction zones for gel structure.
Four water-insoluble (1 → 3)-α-D-glucans, coded L-II 1, L-II2, L-II3 and L-II4, with different molecular weights were isolated from four kinds of fruiting bodies of Lentinus Edodes. The four α-D-glucans were O-sulfonated to obtain derivatives (SL-II) having degrees of substitution (DS) from 0.9 to 2.1 respectively. The structure of the samples was analyzed by infrared spectra, elemental analysis, and 13C NMR. The weight-average molecular weight (Mw), radii of gyration (〈s2〉z1/2) and intrinsic viscosity ([η]) of the native α-D-glucans and O-sulfonated derivatives were measured by size-exclusion chromatography combined with laser light scattering (SEC-LLS), LLS, and viscometry in 0.2 M aqueous NaCl and in dimethyl sulfoxide (DMSO) containing 0.25 M LiCl at 25αC respectively. The Mw values of the O-sulfonated derivatives were much lower than those of the native α-D-glucans. The experimental results indicate that the O-sulfonated derivatives are water-soluble and exist as an expanded flexible chain in aqueous solution owing to intramolecular hydrogen bonding or interaction between charge groups. The in vivo and in vitro antitumor activities of the native α-D-glucans and their O-sulfonated derivatives against solid tumor Sarcoma 180 cells were evaluated and compared. Interestingly, all of the O-sulfonated derivatives exhibited higher antitumor activities than those of the native glucans. The results reveal that the effect of O-sulfonation of the α-D-glucan on the improvement of their antitumor activities was considerable.
A water-insoluble (1-->3)-beta-D-glucan isolated from fresh sclerotium of Poria cocos was, respectively, sulfated, carboxymethylated, methylated, hydroxyethylated, and hydroxypropylated, to afford five water-soluble derivatives. Their weight-average molecular masses (Mw) and intrinsic viscosities ([eta]) were determined by size-exclusion chromatography combined with laser light scattering (SEC-LLS), LLS, and viscometry in phosphate buffer solution (PBS) at 37 degrees C. The antitumor activities, against Sarcoma 180 tumor cell (S-180) and gastric carcinoma cell strain (MKN-45 and SGC-7901) of the native beta-glucan and the five derivatives, were tested in vitro and in vivo. The Mw values of the five derivatives in PBS were determined to be 3.8 x 10(4), 18.9 x 10(4), 16.0 x 10(4), 76.8 x 10(4), and 224.3 x 10(4), respectively. The high Mw values of the hydroxyethylated and hydroxypropylated derivatives in aqueous solution resulted from aggregation, and their true Mw values obtained in dimethyl sulfoxide were 20.1 x 10(4) and 19.1 x 10(4). The sulfated and carboxymethylated derivatives having DS of 1.0-1.3 show good water solubility, and exist as relatively expanded chains in aqueous solution. Interestingly, the native beta-glucan did not show antitumor activity, whereas the sulfated and carboxymethylated derivatives exhibit significant antitumor activities against S-180 and gastric carcinoma tumor cells. This work showed that good water solubility, relatively high chain stiffness, and moderate molecular mass of the derivatives in aqueous solution contribute beneficial to enhancement of antitumor activity.
Vaccination with Hepatitis B surface antigen (HBsAg) is being used to prevent HBV infection. The fact that 10% of vaccinees fail to develop protective antibodies has fostered a large body of research for more effective vaccination strategies. Search for new adjuvant, able to selectively trigger protective antibody production, is one of the most promising approaches.The oligosaccharide β-(1→6)-branched β-(1→3) glucohexaose is the basic unit of lentinan and several other fungal β-glucans with immunostimulatory activity. β-glucans stimulate innate immune response mainly through interaction with myeloid cells (macrophages) and dendritic cells.In this study, the ability of synthetic β-(1→6)-branched β-(1→3) glucohexaose analogue (β-glu6) to enhance the immune response to HBsAg has been evaluated. Administration of synthetic β-glu6 i.p. in BALB/c mice greatly enhanced the mobilisation and maturation of macrophages and dendritic cells to co-administered HBsAg, as compared to the antigen alone. The adjuvant effect of β-glu6 was evident in the increase of T and B cell activation in response to HBsAg, as judged by the percentage of CD69-positive CD4+ and CD19+ lymphocytes in the spleen. β-glu6 could significantly enhance the number of IL-4-producing cells in response to HBsAg, while it had no effect on the number of IFN-γ-producing lymphocytes, suggesting a Th2 bias of the immune response. The correlate of protection for HBV vaccination, i.e. the titer of HBsAg-specific antibodies, was greatly enhanced by the use of β-glu6 as a vaccine adjuvant. The IgG1/IgG2a ratio within the anti-HBsAg antibodies was higher in the mice immunised with HBsAg plus β-glu6 than receiving HBsAg alone or mice administered HBsAg with Freund's adjuvant, indicating a shift towards a Th2-biased anti-inflammatory protective antibody response.
WE have reported1 that the polysaccharide lentinan obtained from Lentinus edodes (Berk.) Sing. (a popular edible mushroom in Japan) had a strong antitumour activity against sarcoma 180 implanted subcutaneously in mice, and that almost complete regression of the tumours had been observed after ten doses of 1 mg/kg. Lentinan is a β-(13)-linked linear glucan having a molecular weight of 950,000–1,050,000 according to light scattering methods.
A sandwich-type enzyme immunoassay (EIA) system for quantifying branched (1,3)-β-glucans was established. A polyclonal antibody was purified with antigen-conjugated aminocellulofine and labelled with biotin to be used as the detection antibody. The reactivity of the antibody was restricted to only (1,6)-branched (1,3)-β-glucans. Molecular weight dependency of (1,6)-branched (1,3)-β-glucan in the reactivity was also observed. Alkaline-treated (1,6)-branched (1,3)-β-glucan which was reported to be a single helical conformer, showed a lower absorbance compared to the untreated triple helix conformer. The conformational alteration of the single helix to the triple helix was produced by heating for 15 min at 100°C. The results suggest that EIA has higher reactivity to the triple helical ultrastructure of (1,6)-branched (1,3)-β-glucans, and can be applied to estimate the conformational changes of (1,6)-branched (1,3)-β-glucans.
The water soluble material (LEM) was prepared from the solid culture medium in which Lentinus edodes mycelia were growing actively. An alcohol insoluble material was prepared from LEM and subjected to Sepharose 6B gel filtration. The void fraction (LAP1) was composed mainly of xylose-rich heteroglycan and protein. From LAP1, a heteroglycan fraction (LAF1) was prepared by DEAE-Sepharose CL-6B column chromatography. LAP1 and LAF1 enhanced the incorporation of [3H]thymidine into mouse splenic cells (SPs). At each of the optimum doses, the rate of the incorporation was about 10 times as high with LAF1 as with LAP1. Such mitogenic responses were not induced in nylon-column effluent SPs and thymocytes. sIg-expressed cells were responsive to LAF1, but not to LAP1. Moreover, with each fraction, the incorporation was enhaned more in plastic adherent splenic cells (ADs) than in SPs. The flow cytometric assay revealed that the number of Mac-1+ cells is about 13 times as many in ADs as in SPs and that the number of Ly-5+ or Thy-1.2+ cells is considerably reduced in ADs compared with that in SPs. Thus, the present studies suggest that LAP1 and LAF1 act as mitogens predominantly for mouse splenic macrophages and/or monocytes.
The changes in the contents of an anti-tumor polysaccharide from Lentinus edodes (lentinan) and Grifola frondosa (GGF) during storage were investigated using by an ELISA inhibition assay. When the mushrooms were stored at low temperature, the contents of their anti-tumor polysaccharides show hardly any changes, but their contents decreased markedly at higher temperature (20°C). Moreover, the effect of the extract from Lentinus edodes stored at different temperatures on tumor necrosis factor (TNF)-α and nitric oxide (NO) productions from macrophages was investigated to confirm the influence to the stimulation of macrophages. Because lentinan stimulates macrophages to augment their antitumor activity. Their productions showed little difference between Lentinus edodes stored at low temperature and the fresh mushroom, although the cytokine production decreased significantly in Lentinus edodes stored at 20°C. These results suggest that low-temperature storage is more effective in maintaining not only the quality of the mushrooms but also the contents of anti-tumor polysaccharides as health-beneficient foods.
(1→3)-β-d-Glucans that have β-d-glucopyranosyl units attached by (1→6) linkages as single unit branches enhance the immune system systemically. This enhancement results in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. The (1→3)-β-d-glucan backbone is essential. The most active polymers have degrees of branching (DB) between 0.20 and 0.33. Data suggest both that triple helical structures formed from high molecular weight polymers are possibly important for immunopotentiating activity and that activity is independent of any specific ordered structure. Other data indicate that it is the distribution of the branch units along the backbone chain that is responsible for activity. There are data that indicate both that β-d-glucopyranosyl units are required for immunopotentiating activity and that the specific nature of the substituent is unimportant. There are also data that indicate both that the more water-soluble polymers are more active (up to a certain degree of substitution (DS) or DB) and that some insoluble aggregates are more stimulatory than the soluble polymers. The best conclusion at this time is that the immunopotentiating activity of (1→3)-β-d-glucans depends on a helical conformation and on the presence of hydrophilic groups located on the outside surface of the helix. Immunopotentiation effected by binding of a (1→3)-β-glucan molecule or particle probably includes activation of cytotoxic macrophages, helper T cells, and NK cells, promotion of T cell differentiation, and activation of the alternative complement pathway.
Chemotherapy has shown little antitumor activity against advanced oral squamous cell carcinoma (OSCC) patients. Therefore, there is an urgent need to develop more effective therapeutic methods for patients with advanced OSCC. Lentinan, beta-(1-->3)-D-glucan, an extract from the edible mushroom, Lentinus edodes, has been reported to show direct antitumor effects and various immunomodulatory effects. S-1 is an oral antineoplastic agent that can induce apoptosis in various types of cancer cells, including OSCC. Hence, combined treatment of cancer cells with Lentinan and S-1 might exert dramatic antitumor effects on OSCC cells. In this study, the response of human OSCC cells to Lentinan alone and in combination with S-1 was examined using nude mouse xenograft models. S-1 (6.9 mg/kg/day, 7 times/week) was administered orally and Lentinan (0.1 mg/kg/day, 2 times/week) was injected into peritumoral tissue for three weeks. Apoptotic cells were detected by a TUNEL method. The gene expression level of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT) was determined using microdissection and RT-PCR, and their protein levels were determined using ELISA. Combined therapy of Lentinan and S-1 markedly exerted antitumor effects on human OSCC xenografts and significantly induced apoptotic cells in tumors treated with Lentinan plus S-1. Microdissection and RT-PCR revealed that the expression of TS and DPD mRNA was down-regulated and that expression of OPRT mRNA was up-regulated in tumors administered the combined treatment. Moreover, ELISA indicated that the protein levels of TS and DPD were down-regulated, and that OPRT was up-regulated in tumors treated with the combined therapy. During the experimental period, no loss of body weight was observed in mice treated with the combined therapy. These findings demonstrate that the combination of Lentinan and S-1 is effective against OSCC and has the potential of being a new therapeutic tool for future treatment of these tumors.
Intravenous lentinan administration has life prolongation effect for gastric cancer patients when combined with chemotherapy. Recently, superfine dispersed lentinan--an oral formulation--has become clinically available. In order to evaluate the efficacy of superfine dispersed lentinan, was conducted multicenter clinical study.
Twenty-seven patients with unresectable or recurrent gastric cancer were enrolled and answered the quality of life questionnaire before and 4, 8, and 12 weeks after the initiation of superfine dispersed lentinan administration. Survival times were evaluated according to results of 3-year follow-up survey.
There was no adverse event with causal relation to superfine dispersed lentinan. Median survival time was 17.1 months (95% confidence interval: 6.9-25.9 months) in 26 eligible patients. Six (23%) out of 26 patients were alive longer than 3 years. There was a significant correlation between the quality of life scores at 12 weeks of superfine dispersed lentinan treatment and survival times.
Superfine dispersed lentinan is deemed free of anything harmful. Quality of life status at 12 weeks of superfine dispersed lentinan treatment appears to be a promising prognostic predictor.
Triple helical lentinan, a beta-(1-->3)-D-glucan from Lentinus edodes, was denatured in dimethylsulfoxide (DMSO) into single random coils. The randomly coiled lentinan/DMSO solutions were diluted with pure water to w(H) (the weight fraction of water in the mixed solvent) of 95%, and their intrinsic viscosity [eta], weight-average molecular weight M(w), radius of gyration R(g), and hydrodynamic radius R(h) were investigated at 25 degrees C after over 5-day storage. The [eta] and M(w) values, especially the conformation parameter rho (identical with R(g)/R(h)), of the renatured lentinan were close to those of the originally extracted one, suggesting that random lentinan chains in DMSO were reassembled into triple helical structures. Moreover, the renatured lentinan in 95% water/5% DMSO solution exhibited a unique behavior of triple helical glucans that shear modulus G' decreased sharply at temperature from 8.4 degrees C to 13.3 degrees C with increasing temperature, which was ascribed to the intramolecular conformation transition from ordered triple helical I to disordered triple helical II. The AFM images gave was suggested intuitively evidence that the renatured lentinan mainly existed as rod-like chains, supporting that formation of triple helical structure. The optimal lentinan concentration for triple helical configuration formation was estimated to be over 0.04%. The time dependence of R(h) and UV absorption of the water-diluted lentinan/DMSO solution with an indicator of azo dye of Congo red suggested that renaturation of triple helix was a very rapid process. Moreover, the blue-shift of UV-vis absorption spectra suggested that the dye molecules of Congo red were assembled into supramolecular structure in the hydrophobic cavity of the renatured triple helical lentinan. All the results showed that the triple helical structure formed once the randomly coiled lentinan/DMSO was diluted to the final water content of 95%.
Nutritional supplements or complementary and alternative medicines (CAM) are currently being investigated for their use in preventing, inhibiting, and reversing the progression of cancer. Natural agents and their derivatives such as vitamin A, selenium, green tea, resveratrol, aspirin, and probiotics have potential benefits in chemoprevention. There is also growing evidence for the use of natural products as adjunctive therapy alongside conventional cancer treatments. Nutritional supplements expenditures demonstrated greater growth than pharmaceuticals, with approximately 80% of cancer patients using natural products. Current issues with nutritional supplements use in cancer treatment include insufficient or conflicting evidence, poor quality control, potential interactions with chemotherapy, and potential efficacy in relation to changes in certain biomarkers, but long-term implications remain largely unresolved. Continued research is needed to lend credibility to these potentially valuable naturally driven supplements in the prevention and potentially in the treatment of cancer in conjunction with standard pharmaceuticals.
新潟大学 平成20年3月24日 新大院博(医)第242号
In the present study, the effect of immunochemotherapy with lentinan compared with that of chemotherapy alone was evaluated in patients with advanced gastric cancer through individual patient data (IPD) meta-analysis.
Based on a computerized and manual search, all eligible centrally randomized controlled trials (RCT) which compared chemotherapy regimens with or without lentinan administration for advanced gastric cancer patients were included.
In total, 650 IPD from 5 trials were available. Lentinan significantly prolonged the overall survival (stratified log-rank p=0.011). The overall hazard ratio (HR) was 0.80 (95% confidence interval=0.68-0.95) and there was no heterogeneity between trials. Additionally, lentinan was possibly more effective in patients with lymph-node metastasis than in non-node metastasis patients (P for interaction=0.077).
The addition of lentinan to standard chemotherapy offers a significant advantage over chemotherapy alone in terms of survival for patients with advanced gastric cancer.
Recently, complementary alternative medicine is actively performed for cancer therapy. We investigated the effectiveness of supplementary food containing superfine dispersed lentinan (beta-1,3-glucan) in patients with unresectable or recurrent hepatocellular carcinoma in a multi-center study.
Peripheral blood was collected prior to the test food ingestion and was incubated with fluorescein-labeled lentinan. The rates of lentinan-binding CD14+ monocytes were determined by flow cytometry. Patient survival times were followed up for 3 years.
Thirty-six patients were eligible among 40 enrolled patients. Median survival time of eligible patients was 13.6 months (95% confidence interval, 8.7-18.9 months). Survival times of patients who ingested test food for a mean period of 47 weeks (range, 26 to 145 weeks) were significantly longer than that of patients who ingested for 7 to 12 weeks (p < 0.05). The rates of lentinan-binding cells in CD14+ monocytes showed individual variations (0.1-19.7%; Median, 1.6%). Survival times (median survival time, 16.3 months) of lentinan-high-binding group were significantly longer than those (median survival time, 12.5 months) of lentinan-low-binding group (p < 0.05).
A superfine dispersed lentinan-containing supplementary food is effective for hepatocellular carcinoma patients' survival. Long-time ingestion is preferable. Assessment of lentinan-binding CD14+ monocytes is a promising prognostic predictor.
Oral supplementations of L-arginine and L-lysine show tumor inhibition abilities. The splenic sympathetic nerve is involved in central modulation of cellular immunity and suppresses splenic natural killer cell activity in rats. An intravenous administration of a mixture of 10 mM L-arginine and L-lysine decreased splenic sympathetic nerve activity (splenic-SNA). We examined the effect of L-arginine and L-lysine mixtures on splenic-SNA in urethane-anesthetized rats by administration of 1 ml mixtures of 2 mM, 10 mM, and 50 mM L-arginine and L-lysine. We also studied the effect of the above mixtures on human colon cancer cell proliferation in athymic nude mice. An increase in splenic-SNA and tumor volume (2 mM), no effect (10 mM), and a decrease in both values (50 mM) were seen. Bivariate correlation analysis revealed a positive correlation between changes in splenic-SNA and tumor volume, indicating the tumor suppressing ability of weakened splenic-SNA.
Lentinan, a (1-3)-beta glucan from Lentinus edodes, is an effective immunostimulatory drug. We tested the effects of lentinan during blood-stage infection by Plasmodium yoelii 17XL (P.y17XL). Pre-treatment of mice with lentinan significantly decreased the parasitemia and increased their survival after infection. Enhanced IL-12, IFN-gamma and NO production induced by lentinan in spleen cells of infected mice revealed that the Th1 immune response was stimulated against malaria infection. In vitro and in vivo, lentinan can result in enhanced expression of MHC II, CD80/CD86, and Toll-like receptors (TLR2/TLR4), and increased production of IL-12 in spleen dendritic cells (DCs) co-cultured with parasitized red blood cells (pRBCs). Moreover, both the number of CD4(+)CD25(+) regulatory T cells (Tregs) and the levels of IL-10 secreted by Tregs were reduced by pre-treatment with lentinan in the spleen of malaria-infected mice. Meanwhile, apoptosis of CD4(+) T cell in spleens of mice pretreated with lentinan was significantly reduced. In summary, lentinan can induce protective Th1 immune responses to control the proliferation of malaria parasites during the blood-stage of P.y17XL infection by stimulating maturation of DCs to inhibit negative regulation of the Th1 immune response by Tregs. Taken together, our findings suggest that lentinan has prophylactic potential for the treatment of malaria.
The spleen is an important organ for tumor immunity, and the splenic sympathetic nerve has a suppressive effect on splenic natural killer (NK) cytotoxicity. On the basis of this and reports that Lentinus edodes (Shiitake mushroom) has tumor-inhibitory effects, the authors hypothesized that an extract of a mycelial culture of L. edodes grown in a solid medium of sugar-cane bagasse and defatted rice bran-L.E.M-might affect the sympathetic splenic sympathetic nerve activity (Splenic-SNA) and thus inhibit tumor proliferation. Thus, the effect of L.E.M on Splenic-SNA and human cancer cell proliferation was examined. Splenic-SNA was found to be suppressed by an intraduodenal L.E.M injection in urethane-anesthetized rats, which significantly inhibited increases in the tumor volume of human colon and breast cancer cells implanted in athymic nude mice. These findings suggest that L.E.M has an inhibitory effect on tumor proliferation possibly via a reduction in NK cytotoxicity through the suppression of Splenic-SNA.
The purpose of this research is to study the effect of sulfated lentinan (sLNT) on immune effect of Newcastle disease (ND) vaccine. In immune response test, 14-day-old chickens were vaccinated with ND vaccine then grouped respectively to inject three sLNTs at two doses, once a day for three successive days, taking non-sulfated lentinan (LNT) as the control. The changes of serum antibody titer and peripheral lymphocyte proliferation were determined before and after vaccination. In immune protection test, 35-day-old chickens were challenged with ND virus (NDV) after treated similar to above mentioned. The morbidity and mortality of chickens were observed, and the changes of serum antibody titer and peripheral lymphocyte proliferation were measured before and after challenge. The results showed that three modified sLNTs could significantly enhance serum antibody titer and promote lymphocyte proliferation in two experimental chickens, and reduce morbidity and mortality of chickens challenged with NDV, which were better than that of non-modified LNT. Their high doses in enhancing antibody titer and low doses in promoting lymphocyte proliferation were more preferable. These results indicated that sulfated modification could enhance the adjuvanticity of LNT and improve the immune effect of ND vaccine. sLNT(2) possessed the best efficacy and would be expected as the candidate of a new-type immune adjuvant.
Glucans have a long history as nonspecific biological modulators. We compared the effects of three different glucans on immune reactions. Using two different administrations (intraperitoneal and oral) and two different animal models, we showed that yeast-derived Betamune (Biorigin, São Paulo, Brazil) caused significant stimulation of phagocytic activity as well as potentiation of synthesis and release of interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-13, and tumor necrosis factor-alpha. In addition, Betamune inhibited growth of tumor cells in vivo and affected expression of several important genes in breast cancer cells. Compared to adult mice, young animals showed different sensitivity to glucan action.
Hepatocellular carcinoma (HCC) is one of the most common cancer-related causes of death worldwide and there is a clear need for further treatment options. In this study, we assessed the efficacy of a combination of lentinan (a fungal extract), transcatheter arterial chemoembolisation (TACE) and radiofrequency ablation (RFA) in HCC patients.
Seventy-eight patients with HCC confirmed by pathology and iconographical checks were used in this study. A total of 136 tumours with a mean diameter of 6.5 cm were detected (standard deviation [SD]+/-0.7). Subjects were divided into four groups, receiving either TACE only, RFA only, RFA and TACE, or the combination group - receiving lentinan, RFA and TACE.
The tumour necrosis was significantly higher in the combination group (88.6%), compared to the TACE group (37.5%), the RFA group (47.8%) and the TACE/RFA group (60.3%; P<0.05). The tumour recurrence rate was significantly lower in the combination group (17.8%), compared to the TACE group (45.8%), the RFA group (34.7%) and the TACE/RFA group (29.0%; P<0.05). Finally, mean survival duration was significantly higher in the combination group (28.2 months; P<0.05).
Combination therapy involving lentinan, RFA and TACE was beneficial in terms of increasing mean survival duration, tumour necrosis and reducing the recurrence rate. Lentinan may therefore be of benefit to HCC patients.
The structure of lentinan, an anti-tumor polysaccharide from Lentinus edodes, has been further investigated. Periodate oxidation, Smith degradation, methylation analysis, and bioassay were the principal methods used. These studies showed that a branched molecule having a backbone of (1→3)-β-d-glucan and side chains of both β-d-(1→3)- and β-d-(1→6)-linked d-glucose residues, together with a few internal β-d-(1→6)-linkages, is present.
A new antitumor and antiviral substance, KS-2, was prepared by ethanol precipitation of the hot water extract of culture mycelia of Lentinus edodes KSLE 007. It was further purified by ECTEOLA-cellulose and Sephadex G-100 column chromatography based on the interferon-inducing activity. Its homogeneity was revealed by CsCl density gradient centrifugation, electrophoresis on cellulose acetate and Sephadex G-100 and ECTEOLA-cellulose column chromatography. KS-2 is mainly composed of alpha-linked mannose and contains a small amount of peptide which consists of serine, threonine and alanine with residual amounts of the other amino acids. The estimated molecular weight of KS-2 is between 6.0 X 10(4) and 9.5 X 10(4). KS-2 suppressed the growth of EHRLICH as well as Sarcoma-180 tumors in mice when given either orally or intraperitoneally. It is also capable of inducing an interferon in mice when dosed orally or intraperitoneally. The acute LD50 of KS-2 was found to be extremely low, more than 12,500 mg/kg when administered orally to mice.
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.
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.
The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the function of peritoneal macrophages in CDF1 mice was examined. Oral administration of SSG (20, 40, 80 or 160 mg/kg, daily for 10 consecutive days) enhanced the acid phosphatase activity of peritoneal macrophages. The greatest enhancing effect was observed at 80 mg/kg of SSG. Relatively long periods of administration (more than 10 consecutive days) were needed to induce significant enhancing effects. Phagocytic activity, candidacidal activity, hydrogen peroxide (H2O2) production and interleukin-1 (IL-1) production of peritoneal macrophages were also enhanced after the administration of SSG by the oral route (80 or 160 mg/kg). However, the durations of the activated state after completion of administration differed depending on the activity. Enhanced activity of lysosomal enzyme (acid phosphatase) was also shown in peritoneal macrophages taken from C3H/HeJ mice, which is a nonresponder strain to bacterial lipopolysaccharide (LPS). These results demonstrate that SSG given by the oral route can activate peritoneal macrophages in mice.
The binding of the iC3b receptor (CR3) to unopsonized zymosan was shown to result from CR3 attachment to cell wall beta-glucans. A specificity of neutrophil responses for beta-glucan was first suggested by a comparison of yeast (Saccharomyces cerevisiae) cell wall components for stimulation of a neutrophil superoxide burst. Neutrophils responded poorly to heat-killed yeast, but gave increasingly better responses to cell wall polysaccharides devoid of proteins (zymosan) and nearly pure beta-glucan particles derived from zymosan. Zymosan triggered a burst that was 29% as great as that stimulated by phorbol myristate acetate (PMA), and beta-glucan particles stimulated a burst that was 72% as great as that produced by PMA. Phagocytic responses to yeast were also inhibited by soluble glucans but not by soluble mannans. Three types of experiments demonstrated a role for CR3 in these responses. First, neutrophil ingestion of either yeast or yeast-derived beta-glucan particles was blocked by monoclonal anti-CR3, fluid-phase iC3b, or soluble beta-glucan from barley. Monocyte ingestion of beta-glucan particles was also blocked by anti-CR3, but not by anti-CR1 or anti-C3. Second, the neutrophil superoxide burst response to either zymosan or beta-glucan particles was blocked by anti-CR3 or fluid-phase iC3b, and was completely absent with neutrophils from 3 patients with an inherited deficiency of CR3. Third, CR3 was isolated from solubilized neutrophils by affinity chromatography on beta-glucan-Sepharose.
The antitumor and metastasis-inhibitory activities, mode of action, and clinical application of lentinan, a strictly purified beta-1,6:beta-1,3-glucan, are reviewed. Lentinan exerts a prominent antitumor effect and prevents chemical and viral oncogenesis. The antitumor action of lentinan is host-mediated. Compared to other well-known immunostimulants, such as bacille Calmette Guérin (BCG), Corynebacterium parvum, and lipopolysaccharide (LPS), lentinan appears to represent a unique class of immunopotentiator, a T cell-oriented adjuvant. Lentinan triggers the increased production of various kinds of bioactive serum factors associated with immunity and inflammation, such as IL-1, CSF, IL-3, vascular dilation inducer, and acute-phase protein inducer, by the direct impact of macrophages or indirectly via lentinan-stimulated T cells, which results in the induction of many immunobiological changes in the host. Augmented IL-1 production amplifies the maturation of immature effector cells to mature cells capable of responding to lymphokines such as IL-2 and T cell-replacing factors. Because of this mode of action, intact T cell compartments for antitumor activity of lentinan are required. Lentinan has little toxic side effects. Excellent results were obtained in a 4 year follow-up of the randomized control study of lentinan in phase III on patients with advanced and recurrent stomach and colorectal cancer.
The powdered fruit bodies of shiitake (Lentinus edodes) showed antitumor activity when given orally to mice. The growth of tumors, both syngeneic and allogeneic, was inhibited by 57.9 to 78.6% in shiitake-fed mice. The degree of inhibition was proportional to the consumption of the experimental diet (L-feed) and was evident even when the administration was started from the 7th day after tumor implantation. The inhibition of tumor growth was mainly due to a glucan contained in the fruit bodies, but the lipid fracton also had inhibitory effects, although mild. Feeding of the fruit bodies to mice in the diet was found to augment both the ability of macrophages to phagocytose latex particles and the spreading activity of the macrophages.
From the culture medium of Lentinus edodes mycelia, water-soluble material (LEM) was prepared and further fractionated by alcohol precipitation and gel filtration on Sepharose 6B. The resulting fraction of xylose-rich proteoglycan at the void volume was designated as LAP1. The 25% and 50% survival rates of hepatoma-bearing rats were raised by intraperitoneal (i.p.) administration of LAP1 at doses of 3-10 mg/kg (an optimum dose, 3 mg/kg). This fraction did not suppress in vitro cell proliferation of the hepatoma. Moreover, the i.p. administration of LAP1 significantly augmented the activity of macrophage-migration inhibition of the splenic cells from hepatoma-bearing rats in the early stage after transplantation. Thus, the anticarcinogenic action of LAP1 would partly be interpreted by host-dependent immunomodulation.