The use of lentinan for treating gastric cancer

Uptake of intraperitoneally administrated triple helical β-glucan for antitumor activity in murine tumor models

Triple helical β-glucan (THG) was captured by macrophages and degraded into small fragments to activate neutrophils, leading to apoptosis of tumor cells.

Mushroom Polysaccharides: Chemistry and Antiobesity, Antidiabetes, Anticancer, and Antibiotic Properties in Cells, Rodents, and Humans

More than 2000 species of edible and/or medicinal mushrooms have been identified to date, many of which are widely consumed, stimulating much research on their health-promoting properties. These properties are associated with bioactive compounds produced by the mushrooms, including polysaccharides. Although β-glucans (homopolysaccharides) are believed to be the major bioactive polysaccharides of mushrooms, other types of mushroom polysaccharides (heteropolysaccharides) also possess biological properties. Here we survey the chemistry of such health-promoting polysaccharides and their reported antiobesity and antidiabetic properties as well as selected anticarcinogenic, antimicrobial, and antiviral effects that demonstrate their multiple health-promoting potential. The associated antioxidative, anti-inflammatory, and immunomodulating activities in fat cells, rodents, and humans are also discussed. The mechanisms of action involve the gut microbiota, meaning the polysaccharides act as prebiotics in the digestive system. Also covered here are the nutritional, functional food, clinical, and epidemiological studies designed to assess the health-promoting properties of polysaccharides, individually and as blended mixtures, against obesity, diabetes, cancer, and infectious diseases, and suggestions for further research. The collated information and suggested research needs might guide further studies needed for a better understanding of the health-promoting properties of mushroom polysaccharides and enhance their use to help prevent and treat human chronic diseases.

Shiitake Mushroom Dermatitis: A Review

Shiitake mushroom dermatitis is a cutaneous reaction caused by the consumption of raw or undercooked shiitake mushrooms. Symptoms include linear erythematous eruptions with papules, papulovesicles or plaques, and severe pruritus. It is likely caused by lentinan, a heat-inactivated beta-glucan polysaccharide. Cases were initially reported in Japan but have now been documented in other Asian countries, North America, South America, and Europe, as this mushroom is now cultivated and consumed worldwide. Shiitake mushroom dermatitis may result from mushroom ingestion or from handling, which can result in an allergic contact dermatitis.

The structure of mushroom polysaccharides and their beneficial role in health

Mushroom is a kind of fungus that has been popular for its special flavour and renowned biological values. The polysaccharide contained in mushroom is regarded as one of the primary bioactive constituents and is beneficial for health. The structural features and bioactivities of mushroom polysaccharides have been studied extensively. It is believed that the diverse biological bioactivities of polysaccharides are closely related to their structure or conformation properties. In this review, the structural characteristics, conformational features and bioactivities of several mushroom polysaccharides are summarized, and their beneficial mechanisms and the relationships between their structure and bioactivities are also discussed.

Gemmata species: Planctomycetes of medical interest

The Planctomycetes genus Gemmata is represented by both uncultured organisms and cultured Gemmata obscuriglobus and 'Gemmata massiliana' organisms. Their plasmidless 9.2 Mb genomes encode a complex cell plan, cell signaling capacities, antibiotic and trace metal resistance and multidrug resistance efflux pumps. As they lack iron metabolism pathways, they are fastidious. Gemmata spp. are mainly found in aquatic and soil environments but have also been found in hospital water networks in close proximity to patients, in animals, on human skin, the gut microbiota and in the blood of aplastic leukemic patients. Due to their panoply of attack and defense mechanisms and their recently demonstrated association with humans, the potential of Gemmata organisms to behave as opportunistic pathogens should be more widely recognized.

Lentinan ameliorates burn sepsis by attenuating CD4+ CD25+ Tregs

AIM

The aim of our study was to investigate the effect of lentinan on regulatory T cells (Tregs) in sepsis, especially on the generation of interleukin (IL)-10 via regulation of Erk-FoxO1 signaling.

METHODS

BalB/c mice were randomized into five groups: sham group, the group with burns plus Pseudomonas aeruginosa infection, and the groups with burns plus P. aeruginosa infection administered 40, 100, and 250mg/kg of lentinan. The mice were sacrificed on postburn days 0, 1, 2, 3, and 4, respectively, with eight animals per group at each time point. The peripheral blood CD4⁺ CD25⁺ Tregs and CD4⁺ T cells were isolated using magnetic microbeads. The phenotypes were analyzed by flow cytometry. The cytokine levels were determined with enzyme-linked immunosorbent assay (ELISA). Signal transduction was studied by Western blot, quantitative polymerase chain reaction (qPCR), and luciferase assay.

RESULTS

The IL-10-producing capacity of CD4⁺ CD25⁺ Tregs was significantly enhanced in the group with burns plus P. aeruginosa infection, compared with the sham group. Administration of lentinan significantly decreased IL-10 production and FoxP3 expression of CD4⁺ CD25⁺ Tregs. The proliferative activities of CD4⁺ T cells, however, were restored. Lentinan decreased lipopolysaccharide (LPS)-induced IL-10 production in the Tregs isolated from burned mice. In addition, lentinan attenuated LPS-stimulated Erk-FoxO1 activation.

CONCLUSIONS

Lentinan may improve the outcome of postburn sepsis by suppressing LPS-triggered Erk-FoxO1 activation. Consequently, the hyperfunction of CD4⁺ CD25⁺ Tregs is inhibited, leading to a shift in the inflammatory status from Th2 to Th1 in postburn sepsis.

Lentinan mitigates therarubicin-induced myelosuppression by activating bone marrow-derived macrophages in an MAPK/NF-κB-dependent manner

Bone marrow (BM) suppression (also known as myelosuppression) is the most common and most severe side-effect of therarubicin (THP) and thereby limits the clinical application of this anticancer agent. Lentinan (LNT), a glucan extracted from dried shiitake mushrooms (Lentinula edodes), exhibits a variety of pharmacological activities. The objectives of the present study were to determine the effect of LNT on the myelosuppression of THP-treated mice and to examine the pharmacological mechanism of these effects. In vivo experiments indicated that non-cytotoxic levels of LNT strongly increased blood myeloperoxidase (MPO) activity; improved BM structural injuries; increased the numbers of leukocytes and neutrophils in the blood and BM; elevated the blood levels of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF); and reduced the self-healing period in THP-treated mice. In vitro experiments indicated that LNT increased the viability of BM-derived macrophages (BMDMs) in a time- and dose-dependent manner without toxic side-effects and markedly increased the release of G-CSF, GM-CSF and M-CSF by BMDMs. Further analyses revealed that LNT activated the NF-κB and MAPK signalling pathways and promoted the nuclear import of p65 and that BAY 11-7082 (a specific inhibitor of NF-κB) suppressed the release of G-CSF, GM-CSF and M-CSF. Furthermore, we found that U0126, SB203580 and SP600125 (specific inhibitors of ERK, p38 and JNK, respectively) markedly inhibited the IKK/IκB/NF-κB-dependent release of G-CSF, GM-CSF and M-CSF. In conclusion, LNT induces the production of G-CSF, GM-CSF and M-CSF by activating the MAPK/NF-κB signalling pathway in BM cells, thereby mitigating THP-induced myelosuppression.

Chemo-Immunotherapy Using Lentinan for the Treatment of Gastric Cancer with Liver Metastases

Gastric cancer is the third leading cause of cancer-related mortality worldwide. Systemic chemotherapy is the main treatment option for advanced gastric cancer when the tumor is inoperable. Despite recent advances in chemotherapeutic agents, the prognosis of unresectable or recurrent gastric cancer remains extremely poor. In Japan, combination therapy including S-1 and cisplatin is the standard first-line treatment for advanced gastric cancer; however, the five-year survival rate remains very low. Lentinan, the backbone of beta-(1,3)-glucan with beta-(1,6) branches, an active ingredient purified from Shiitake mushrooms, has been approved as a biological response modifier for the treatment of gastric cancer. This agent has been used in combination with oral fluoropyrimidines to improve the overall survival of gastric cancer patients. A retrospective chart review on 138 metastatic gastric cancer patients receiving chemotherapy was performed in Nagoya Memorial Hospital from 1 September 2010 to 31 August 2015. 12 patients with liver metastases were treated by lentinan in combination with S-1-based chemotherapy. The rate of objective response was 42% (5/12) and the disease control rate was 83% (10/12) in response to chemo-immunotherapy using lentinan, with a median overall survival of 407 days (95% CI: 207-700 days).

A proteomic analysis of mushroom polysaccharide-treated HepG2 cells

The anti-tumor properties of fungal polysaccharides have gained significant recognition in Asia and tropical America. In this study, the differential expression of proteins in normal HepG2 cells and those treated with polysaccharides that had been isolated from Phellinus linteus (PL), Ganoderma lucidum (GL) and Auricularia auricula (AA) was investigated. Using two-dimensional electrophoresis (2DE), a total of 104 protein spots were determined to be overexpressed in these cells compared with noncancerous regions. A total of 59 differentially expressed proteins were identified through MALDI-TOF-MS. In addition, 400 biological processes (BP), 133 cell components (CC) and 146 molecular functions (MF) were enriched by Gene Ontology (GO) analysis, and 78 KEGG pathways were enriched by pathway enrichment. Protein-Protein Interaction (PPI) analysis demonstrated the interaction networks affected by polysaccharides in HepG2 cells. Then, DJ-1 and 14-3-3 were identified as the key proteins in the networks, and the expression of the mRNA and proteins were evaluated using Real-time quantitative PCR (qRT-PCR) and Western blotting (WB), respectively. The results were in agreement with the 2DE. These results provided information on significant proteins of hepatocellular carcinoma (HCC) and form an important basis for the future development of valuable medicinal mushroom resources.

Are mushrooms medicinal?

Despite the longstanding use of dried mushrooms and mushroom extracts in traditional Chinese medicine, there is no scientific evidence to support the effectiveness of these preparations in the treatment of human disease. Consumers should evaluate assertions made by companies about the miraculous properties of medicinal mushrooms very critically. The potential harm caused by these natural products is another important consideration. In a more positive vein, the presence of potent toxins and neurotropic compounds in basidiomycete fruit bodies suggests that secondary metabolites with useful pharmacological properties are widespread in these fungi. Major investment in controlled experiments and objective clinical trials is necessary to develop this natural pharmacopeia.

The dual induction of apoptosis and autophagy by SZC014, a synthetic oleanolic acid derivative, in gastric cancer cells via NF-κB pathway

Oleanolic acid (OA) possesses various pharmacological activities, such as antitumor and anti-inflammation; however, its clinical applications are limited by its relatively weak activities and low bioavailability. In this study, we evaluated the cytotoxic activity of seven novel OA derivatives, one of which, SZC014 [2-(pyrrolidine-1-yl) methyl-3-oxo-olean-12-en-28-oic acid], exhibited the strongest antitumor activity; its anticancer effect on gastric cancer cells and action mechanisms were investigated. The viability of OA and seven synthesized derivatives treating gastric cancer cells was detected using tetrazolium (MTT). Among them, SZC014 exhibited the strongest cytotoxic activity against gastric cancer cells (SGC7901, MGC803, and MKN-45). The effect of SZC014 on cell cycle was identified by propidium iodide (PI) staining assay. The cellular apoptosis induced by SZC014 was tested by annexin V/PI. The cellular morphological changes and ultrastructural structures affected by SZC014 were observed and imaged through inverted phase contrast microscope and transmission electron microscopy. Western blotting was performed to explore the expression of proteins associated with apoptosis (caspase 3, caspase 9, Bax, Bcl-2, and Bcl-xL), autophagy (Beclin 1 and ATG 5), and nuclear factor-κB (NF-κB) signal pathway, respectively. The cytotoxic activities of all the seven synthesized OA derivatives were stronger than that of OA against gastric cancer cells. SZC014 exhibited stronger cytotoxic activity than other OA derivatives, inhibited the proliferation of gastric cancer cells, besides, induced G2/M phase cell cycle arrest in SGC7901 cells. Both apoptosis and autophagy were found simultaneously in SZC014-treated SGC7901 cells. Caspase-dependent apoptosis induced by SZC014 was confirmed to be associated with upregulation of Bax and downregulation of Bcl-2 and Bcl-xL, while upregulation of Beclin 1 and ATG 5 was inferred to be involved in SZC014-induced autophagy. Moreover, treating cells with SZC014 resulted in a decrease in phosphorylation of IκBα and NF-κB/p65 and NF-κB/p65 nuclear translocation. The cytotoxic activities of seven OA derivatives were generally stronger than that of OA, among which, SZC014 possessed the most potent anticancer activity in SGC7901 cells and would be a promising chemotherapic agent for the treatment of gastric cancer.

Exopolysaccharide from Trichoderma pseudokoningii induces the apoptosis of MCF-7 cells through an intrinsic mitochondrial pathway

In this study, we reported the anticancer efficacy of exopolysaccharide (EPS) derived from Trichoderma pseudokoningii, on human breast cancer MCF-7 cells. Our results showed that EPS inhibited the proliferation of MCF-7 cells and induced lactic dehydrogenase release by inducing apoptosis and cell arrest at S phase. Further study revealed that EPS-induced apoptosis of MCF-7 cells was associated with alteration of nuclear morphology, disruption of mitochondrial membrane potential and accumulation of intracellular reactive oxygen species. Sequentially, EPS increased the activation of caspase-9 and caspase-3 in a dose-dependent manner; however, caspase-8 remained intact. Western blot analysis revealed that EPS increased the ratio of Bax/Bcl-2 and promoted the release of cytochrome c into the cytoplasm. Taken together, these findings provided evidence that EPS induced the apoptosis of MCF-7 cells through an intrinsic mitochondrial apoptotic pathway and that EPS may therefore be considered as an effective adjuvant agent against human breast cancer.

Scavenger Receptors: Emerging Roles in Cancer Biology and Immunology

Scavenger receptors constitute a large family of evolutionally conserved protein molecules that are structurally and functionally diverse. Although scavenger receptors were originally identified based on their capacity to scavenge modified lipoproteins, these molecules have been shown to recognize and bind to a broad spectrum of ligands, including modified and unmodified host-derived molecules or microbial components. As a major subset of innate pattern recognition receptors, scavenger receptors are mainly expressed on myeloid cells and function in a wide range of biological processes, such as endocytosis, adhesion, lipid transport, antigen presentation, and pathogen clearance. In addition to playing a crucial role in maintenance of host homeostasis, scavenger receptors have been implicated in the pathogenesis of a number of diseases, e.g., atherosclerosis, neurodegeneration, or metabolic disorders. Emerging evidence has begun to reveal these receptor molecules as important regulators of tumor behavior and host immune responses to cancer. This review summarizes our current understanding on the newly identified, distinct functions of scavenger receptors in cancer biology and immunology. The potential of scavenger receptors as diagnostic biomarkers and novel targets for therapeutic interventions to treat malignancies is also highlighted.

(+)-Epogymnolactam, a novel autophagy inducer from mycelial culture of Gymnopus sp

Mushrooms, including Ganoderma lucidum, have been used as a potential source of therapeutic compounds, and an autophagy inducer would be useful for treatment of diverse diseases in human. Reported here is a full account of screening, isolation, structural determination, and biological activity of an autophagy inducer, (+)-epogymnolactam (1) from a mycelial culture of a Gymnopus sp. strain. Its structure was elucidated by HR-ESI-MS, NMR, and its plus sign by specific rotation. It exists as a tautomeric mixture of 1a and 1b in MeOH. The major tautomer of 1 is (1R,5S)-4-butyl-4-hydroxy-3-aza-6-oxa-bicyclo[3.1.0]hexan-2-one (1a), and the minor tautomeric form is (2R,3S)-3-pentanoyloxirane-2-carboxamide (1b).

Lentinan exerts synergistic apoptotic effects with paclitaxel in A549 cells via activating ROS-TXNIP-NLRP3 inflammasome

Paclitaxel is generally used to treat cancers in clinic as an inhibitor of cell division. However, the acquired resistance in tumours limits its clinical efficacy. Therefore, the aim of this study was to detect whether co-treatment with lentinan enhanced the anti-cancer effects of paclitaxel in A549 cells. We found that the combination of paclitaxel and lentinan resulted in a significantly stronger inhibition on A549 cell proliferation than paclitaxel treatment alone. Co-treatment with paclitaxel and lentinan enhanced cell apoptosis rate by inducing caspase-3 activation. Furthermore, co-treatment with paclitaxel and lentinan significantly triggered reactive oxygen species (ROS) production, and increased thioredoxin-interacting protein (TXNIP) expression. Moreover, co-treatment with paclitaxel and lentinan enhanced TXNIP-NLRP3 interaction, and activated NLRP3 inflammasome whereat interleukin-1β levels were increased and cell apoptosis was induced. In addition, combination of paclitaxel and lentinan could activate apoptosis signal regulating kinase-1 (ASK1)/p38 mitogen-activated protein kinase (MAPK) signal which also contributed to cell apoptosis. Taken together, co-treatment with paclitaxel and lentinan exerts synergistic apoptotic effects in A549 cells through inducing ROS production, and activating NLRP3 inflammasome and ASK1/p38 MAPK signal pathway.

Drying enhances immunoactivity of spent brewer's yeast cell wall β-D-glucans

Due to immunological activity, microbial cell wall polysaccharides are defined as 'biological response modifiers' (BRM). Cell walls of spent brewer's yeast also have some BRM activity. However, up to date there is no consensus on the use of spent brewer's yeast D-glucan as specific BRM in humans or animals. The aim of this paper is to demonstrate the potential of spent brewer's yeast β-D-glucans as BRM, and drying as an efficient pretreatment to increase β-D-glucan's immunogenic activity. Our results revealed that drying does not change spent brewer's yeast biomass carbohydrate content as well as the chemical structure of purified β-D-glucan. However, drying increased purified β-D-glucan TNF-α induction activity in the murine macrophage model. We presume drying pretreatment enhances purity of extracted β-D-glucan. This is corroborated with FT-IR analyses of the β-D-glucan spectra. Based on our results, we suggest that dry spent brewer's yeast biomass can be used as a cheap source for high-quality β-D-glucan extraction. Drying in combination with carboxylmethylation (CM), endows spent brewer's yeast β-D-glucan with the immunoactivity similar or exceeding that of a well-characterized fungal BRM pleuran.

Glucan supplementation enhances the immune response against an influenza challenge in mice

BACKGROUND

The strong immunostimulating potential of β-glucans has been well established in numerous diseases. However, the effects on viral infection were less studied.

METHODS

In our study, we focused on possible effects of a special combined glucan formulation on immunosuppression caused by influenza infection.

RESULTS

We found that a 2-week oral feeding with glucan mixture significantly reduced the effects of influenza infection in total mortality. Our study was focused on phagocytosis, cytokine levels, antibody response and cytotoxicity assay.

CONCLUSIONS

Based on our data, we concluded that these effects are caused by stimulation of both cellular and humoral immune reaction resulting in lower viral load.

Screening of antimicrobial, antioxidant properties and bioactive compounds of some edible mushrooms cultivated in Bangladesh

BACKGROUND

For a long time mushrooms have been playing an important role in several aspects of the human activity. Recently edible mushrooms are used extensively in cooking and make part of new food in Bangladesh for their beneficial properties. The aim of this study is to screen some values of mushrooms used in Bangladesh.

METHODS

Methanolic extracts of 3 edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Hypsizigus tessulatus) isolated from Chittagong, Bangladesh were used in this study. Phenolic compounds in the mushroom methanolic extracts were estimated by a colorimetric assay. The antioxidant activity was determined by radical 1, 1-diphenyl;-2-picrylhydrazyl (DPPH) radical scavenging assay. Eight microbial isolates were used for antimicrobial activity of methanolic extract of mushrooms by the agar well diffusion method with slight modification.

RESULTS

Determination of antimicrobial activity indicated considerable activity against all bacteria and fungi reveling zone of inhibition ranged from 7 ± 0.2 to 20 ± 0.1 mm. Minimum inhibitory concentration values of the extracts showed that they are also active even in least concentrations ranged from 1 mg/ml to 9 mg/ml. Lentinula edodes showed the best antimicrobial activity than others. Pseudomonas aeruginosa was quite resistant and Saccharomyces cerevisiae was more sensitive than others microbial isolates. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like ascorbic Acid . The concentration (IC50) ranged from 100 ± 1.20 to 110 ± 1.24 μg/ml. Total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 to 10.66 ± 0.52 mg/ml. Average concentration of flavonoid ranged from 2.50 ± 0.008 mg/ml to 4.76 ± 0.11 mg/ml; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.00 mg/ml to 0.21 ± 0.01 mg/ml) in all the isolates. All the isolates showed high phenol and flavonoid content (except Pleurotus ostreatus), but ascorbic acid content was found in traces.

CONCLUSION

This study has revealed that selected edible mushrooms have not only nutritional values but also some therapeutic values. Proper and more investigations can lead us to use these as strong medicine in future.

Lentinan reduces tumor progression by enhancing gemcitabine chemotherapy in urothelial bladder cancer

It has been shown that chemotherapy has limited antitumor activity against advanced urothelial bladder cancer (UBC). Consequently, there is an urgent need to develop effective therapeutic methods for patients with advanced UBC. In the present study, the inhibitory effects of lentinan alone, gemcitabine alone, or lentinan combined with gemcitabine on the proliferation of the UBC cell line, T24, were investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, annexin V fluorescein isothiocyanate/propidium iodide staining, and flow cytometry were used to determine the proliferation and apoptosis of T24 cells in each treatment group. Survival-related protein expression was analyzed by western blotting. Increased concentrations of lentinan, or lentinan combined with gemcitabine, positively correlated with decreased T24 cell proliferation. Lentinan combined with gemcitabine chemotherapy significantly inhibited UBC cell proliferation. Gemcitabine has the ability to induce T24 cell apoptosis, and this effect is enhanced when it is combined with lentinan.

Immune-enhancing effects of Maitake (Grifola frondosa) and Shiitake (Lentinula edodes) extracts

BACKGROUND

The role of glucan in stimulation of immune reactions has been studied for several decades. In this report, we focused on the effects of orally administered glucan Maitake and Shiitake on immune reactions.

MATERIALS AND METHODS

We measured phagocytosis, NK cell activity, and secretion of IL-6, IL-12, IFN-γ as well as C-reactive protein (CRP) after 14 days of oral application of tested glucans. For comparison, active hexose correlated compound (AHCC) was used in all reactions.

RESULTS

We found significant stimulation of defense reaction. In all cases, the most active was the Maitake-Shiitake combination, with Maitake alone being the second strongest, followed by Shiitake on its own and AHCC.

CONCLUSIONS

Short-term oral application of natural immunomodulating glucans from Maitake and Shiitake mushrooms strongly stimulated both the cellular and humoral branch of immune reactions. These activities were significantly higher than those of AHCC.

Effect of lentinan on membrane-bound protein expression in splenic lymphocytes under chronic low-dose radiation

We investigated the protective effects of lentinan against damages to chronic and low-dose radiation (CL-radiation) by using mouse models. The mice were randomized divided into four groups: normal control mice (Ctr), mice exposed to radiation (Rad), irradiated mice treated with low-dose lentinan (0.1mg/(kg.d), RL), and irradiated mice treated with high-dose lentinan (0.5mg/(kg.d), RH). All the mice were injected intraperitoneally once a day at a dose of 0.5mL (Ctr and Rad with normal sodium while RL and RH with lentinan). The success of radiation models was confirmed by HE stain and cell morphology by a transmission electron microscope (TEM). On the basis of radiation models, we investigated the expression of proteins on the membrane of splenic cells through MALDI-TOF-MS/MS. The results demonstrated that both RT-radiation and lentinan affected the expression of membrane proteins, but lentinan protected the splenic cells and tissue from the injuries caused by CL-radiation. Therefore, we speculated that CL-radiation mainly damages the genetic materials and membrane-bound proteins, while lentinan protects membrane-bound proteins by regulating signal transduction and the appearance of the cells.

Effects of β-glucan on some environmental toxins: An overview

BACKGROUND

Beta-glucans are naturally occurring polysaccharides and constituents of the cell wall of certain pathogenic bacteria and fungi. They have proven healing and immunostimulating properties, linked to enhanced macrophage and natural killer cell function which likely involves specific interaction with several cell surface receptors, such as lactosylceramide, selected scavenger receptors, and dectin-1 (betaGR). In particular, glucan reduces the immunosuppressive effects of a number of agents including chemo therapy and radiation. More recent studies suggest a positive function for glucan in the immunosuppression caused by toxic agents in the environment.

AIM

An overview of the effects of glucan on the mycotoxin, aflotoxin and other environmental toxins (mercury-thimerosal, depleted uranium).

CONCLUSION

Glucan is effective as a natural immunomodulator and could be used as an inexpensive solution to reducing the adverse effects of some environmental toxins.

Alocasia cucullata exhibits strong antitumor effect in vivo by activating antitumor immunity

Chinese herbal medicines have long been used to treat various illnesses by modulating the human immune response. In this study, we investigate the immuno-modulating effect and antitumor activity of Alocasia Cucullata (AC), a Chinese herb traditionally used to treat infection and cancer. We found that the whole water extract of AC roots could significantly attenuate tumor growth in mouse tumor models. The median survival time of the AC-treated mice was 43 days, 16 days longer than that of the control group. Moreover, the AC-treated mice showed substantially higher induction of key antitumor cytokines, such as IL-2, IFN-γ, and TNF-α, indicating that AC may exert antitumor effect by activating antitumor immunity. To further pinpoint the cellular and molecular mechanism of AC, we studied the dose response of a human monocytic cell line, THP-1, to the whole water extract of AC. Treatment of the AC extract significantly induced THP-1 differentiation into macrophage-like cells and the differentiated THP-1 showed expression of specific macrophage surface markers, such as CD11b and CD14, as well as productions of antitumor cytokines, e.g. IFN-γ and TNF-α. Our data thus point to AC as potentially a new, alternative immuno-modulating herbal remedy for anticancer treatment.

Immunostimulatory properties and antitumor activities of glucans (Review)

New foods and natural biological modulators have recently become of scientific interest in the investigation of the value of traditional medical therapeutics. Glucans have an important part in this renewed interest. These fungal wall components are claimed to be useful for various medical purposes and they are obtained from medicinal mushrooms commonly used in traditional Oriental medicine. The immunotherapeutic properties of fungi extracts have been reported, including the enhancement of anticancer immunity responses. These properties are principally related to the stimulation of cells of the innate immune system. The discovery of specific receptors for glucans on dendritic cells (dectin-1), as well as interactions with other receptors, mainly expressed by innate immune cells (e.g., Toll-like receptors, complement receptor-3), have raised new attention toward these products as suitable therapeutic agents. We briefly review the characteristics of the glucans from mycelial walls as modulators of the immunity and their possible use as antitumor treatments.

p-Terphenyl curtisian E inhibits in vitro platelet aggregation via cAMP elevation and VASP phosphorylation

Mushrooms possess untapped source of enormous natural compounds showing anti-inflammatory, antioxidant and anti-platelet activities. Paxillus curtisii, wild mushroom, is a rich source of curtisian E (CE) reported for neuroprotective effects; however, its anti-platelet effect was unknown. Here, therefore, we investigated the anti-platelet activity of CE in rat platelets. Curtisian E (12.5-200μM) attenuated collagen (2.5μg/ml), thrombin (0.1U/ml) and ADP (10μM) induced platelet aggregation in vitro. Likewise, CE diminished intracellular calcium and adenosine triphosphate (ATP) release in collagen activated platelets. Fibrinogen binding and fibronectin adhesion to platelets were also inhibited. While CE downregulated c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38, and Akt dose dependently in collagen stimulated platelets, it upregulated intraplatelet cyclic adenosine monophosphate (cAMP) and vasodilator-stimulated-phosphoprotein (VASP) phosphorylation. Protein kinase A inhibitor (H-89) markedly inhibited p-VASP(157) protein expression, suggesting that cAMP-PKA-VASP(157) pathway may mediate its anti-platelet effect and thus CE could be considered as a potential anti-thrombotic agent.