Therapeutic intervention with complement and beta-glucan in cancer

The dectin 1 agonist curdlan regulates osteoclastogenesis by inhibiting nuclear factor of activated T cells cytoplasmic 1 (NFATc1) through Syk kinase

Several immune system cell surface receptors are reported to be associated with osteoclastogenesis. Dectin 1, a lectin receptor for β-glucan, is found predominantly on cells of the myeloid lineage. In this study, we examined the effect of the dectin 1 agonist curdlan on osteoclastogenesis. In mouse bone marrow cells and dectin 1-overexpressing RAW 264.7 cells (d-RAWs), curdlan suppressed receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation, bone resorption, and actin ring formation in a dose-dependent manner. This was achieved within non-growth inhibitory concentrations at the early stage. Conversely, curdlan had no effect on macrophage colony-stimulating factor-induced differentiation. Furthermore, curdlan inhibited RANKL-induced nuclear factor of activated T cell cytoplasmic 1 (NFATc1) expression, thereby decreasing osteoclastogenesis-related marker gene expression, including tartrate-resistant acid phosphatase, osteoclast stimulatory transmembrane protein, cathepsin K, and matrix metallopeptidase 9. Curdlan inhibited RANKL-induced c-fos expression, followed by suppression of NFATc1 autoamplification, without significantly affecting the NF-κB signaling pathway. We also observed that curdlan treatment decreased Syk protein in d-RAWs. Inhibition of the dectin 1-Syk kinase pathway by Syk-specific siRNA or chemical inhibitors suppressed osteoclast formation and NFATc1 expression stimulated by RANKL. In conclusion, our results demonstrate that curdlan potentially inhibits osteoclast differentiation, especially NFATc1 expression, and that Syk kinase plays a crucial role in the transcriptional pathways. This suggests that the activation of dectin 1-Syk kinase interaction critically regulates the genes required for osteoclastogenesis.

Effect of β-1,3/1,6-D-glucan in diet on productivity and humoral and cellular defense mechanisms in sheep

The aim of this study was to determine the effect of β-1,3/1,6-D-glucan, isolated from Saccharomyces cerevisiae, on indicators of milk and meat performance in sheep as well as on selected non-specific indicators of humoral and cellular defense. The experiment was carried on 26 suckling ewes divided into 2 equal groups, and their offspring (21 in each group). The ewes were administered concentrate with the addition of β-1,3/1,6-D-glucan at a dose of 3 g/kg. Indicators of milk performance and markers of humoral and cellular immunity were analyzed on days 28 and 70 of lactation; and the indicators of meat performance of lambs on day 28 and 70 of their life. The addition of β-1,3/1,6-D-glucan was observed to cause an increase in milk performance by 13.5–14%. Simultaneously, milk was characterized by a lower somatic cell count. Diet supplementation had a positive effect on the chemical composition of milk, which was manifested by increased percentage contents of fat (by 15– 30%) and protein (by 11%). Lambs were characterized by a higher growth rate and better muscle tissue development. The supplementation caused an increase of gamma-globulin concentration (by 6.33–9.5 g/l), lysozyme activity (by 0.1 mg/l), respiratory burst activity (by 0.11–0.14), potential killing activity (by 0.10–0.12), proliferative response of T-cells stimulated by mitogen concanavalineA (by 0.07–0.09 RI) and proliferative response of B-cells stimulated by mitogen lipopolysaccharide (by 0.13–0.16 RI) in sheep’s blood. The activity of β-1,3/1,6-D-glucan as a natural immunostimulator has been studied in many animal species, however, this is the first study conducted on sheep.

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.

Neuroblastoma: developmental biology, cancer genomics and immunotherapy

Neuroblastoma is a solid tumour that arises from the developing sympathetic nervous system. Over the past decade, our understanding of this disease has advanced tremendously. The future challenge is to apply the knowledge gained to developing risk-based therapies and, ultimately, improving outcome. In this Review we discuss the key discoveries in the developmental biology, molecular genetics and immunology of neuroblastoma, as well as new translational tools for bringing these promising scientific advances into the clinic.

Successful therapy of visceral leishmaniasis with curdlan involves T-helper 17 cytokines

The aim of this study was to evaluate and characterize the therapeutic potential of curdlan, a naturally occurring β-glucan immunomodulator, against visceral leishmaniasis, a fatal parasitic disease. Curdlan eliminated the liver and spleen parasite burden in a 45-day BALB/c mouse model of visceral leishmaniasis at a dosage of 10 mg/kg/day as determined by Giemsa-stained organ impression smears. Curdlan was associated with production of the disease-resolving T-helper (Th) 1 and Th17-inducing cytokines interleukin (IL)-6, IL-1β, and IL-23, as well as with production of Th17 cytokines IL-17 and IL-22, as determined by enzyme-linked immunosorbent assay (ELISA) and real time polymerase chain reaction (RT-PCR). Reversal of curdlan-mediated protection by anti-IL-17 and anti-IL-23 monoclonal antibodies showed the importance of Th17 cytokines. Significantly decreased production of both IL-17 and IL-22 by mice that received anti-IL-23 antibody suggested the essential role of IL-23 in Th17 differentiation. Although administration of recombinant IL-17 or IL-23 caused significant suppression of the organ parasite burden, with marked generation of interferon γ and nitric oxide (NO), effects were much faster for IL-17. These results documented that although both IL-23 and IL-17 play major roles in the antileishmanial effect of curdlan, the effect of IL-23 may occur indirectly, through the induction of IL-17 production.

Evaluation of the protective effect of Beta glucan on amikacin ototoxicity using distortion product otoacoustic emission measurements in rats

Objectives

This experimental study investigated the possible protective effect of beta glucans on amikacin ototoxicity.

Methods

Thirty-eight rats with normal distortion product otoacoustic emissions (DPOAEs) were divided into four groups. Group K was the control group. Group A was injected intramuscularly (i.m.) with amikacin 600 mg/kg/day between days 1-15. Group AB was given beta glucan gavage 1 mg/kg/day on days 0-15 and given amikacin 600 mg/kg/day i.m. on days 1-15. Group B was administered only beta glucan gavage, 1 mg/kg/day, on days 0-15. The DPOAEs were elicited in different frequency regions between 2,003 and 9,515 Hz, as distortion product diagrams (DPgrams), before and after the medication was administered, in all groups, on days 1, 5, 10, and 15.

Results

No significant changes in the DPgrams were observed in group K. In group A, significant deterioration was observed at the 8,003 and 9,515 Hz frequencies on day 10, and at the 3,991, 4,557, 5,660, 6,726, 8,003, and 9,515 Hz frequencies on day 15. For group AB, statistically significant deterioration was observed at the 2,824, 8,003, and 9,515 Hz frequencies on day 15. The results for group B showed a significant improvement of hearing at the 2,378, 2,824, 3,363, and 3,991 Hz frequencies on day 1, at the 3,363, 3,991, and 8,003 Hz frequencies on day 10, and at the 8,003 Hz frequency on day 15.

Conclusion

This study suggests that amikacin-induced hearing loss in rats may be limited to some extent by concomitant use of beta glucan.

Brucella β 1,2 cyclic glucan is an activator of human and mouse dendritic cells

Bacterial cyclic glucans are glucose polymers that concentrate within the periplasm of alpha-proteobacteria. These molecules are necessary to maintain the homeostasis of the cell envelope by contributing to the osmolarity of Gram negative bacteria. Here, we demonstrate that Brucella β 1,2 cyclic glucans are potent activators of human and mouse dendritic cells. Dendritic cells activation by Brucella β 1,2 cyclic glucans requires TLR4, MyD88 and TRIF, but not CD14. The Brucella cyclic glucans showed neither toxicity nor immunogenicity compared to LPS and triggered antigen-specific CD8⁺ T cell responses in vivo. These cyclic glucans also enhanced antigen-specific CD4⁺ and CD8⁺ T cell responses including cross-presentation by different human DC subsets. Brucella β 1,2 cyclic glucans increased the memory CD4⁺ T cell responses of blood mononuclear cells exposed to recombinant fusion proteins composed of anti-CD40 antibody and antigens from both hepatitis C virus and Mycobacterium tuberculosis. Thus cyclic glucans represent a new class of adjuvants, which might contribute to the development of effective antimicrobial therapies.

Vaccination is one of the key strategies to fight against infectious diseases though numerous diseases remain without appropriate vaccines. The challenge is to generate potent vaccines capable of inducing long-lasting immunity in humans. Successful vaccines include adjuvants that enhance and appropriately skew the immune response to given antigens. The development of new adjuvants for human vaccines has become an expanding field of research. Here we show that bacterial cyclic β-glucans can be used to enhance cellular immunity by activation of dendritic cells, from both mice and humans. In particular, Cyclic-β glucans enhance the in vitro memory CD4+ T cell responses of patients suffering from hepatitis C and tuberculosis. Thus cyclic-β glucans are new adjuvants, which might be used in vaccines.

Anticancer properties of polysaccharides isolated from fungi of the Basidiomycetes class

Basidiomycete mushrooms represent a valuable source of biologically active compounds with anticancer properties. This feature is primarily attributed to polysaccharides and their derivatives. The anticancer potential of polysaccharides is linked to their origin, composition and chemical structure, solubility and method of isolation. Moreover, their activity can be significantly increased by chemical modifications. Anticancer effects of polysaccharides can be expressed indirectly (immunostimulation) or directly (cell proliferation inhibition and/or apoptosis induction). Among the wide range of polysaccharides with documented anticancer properties, lentinan, polysaccharide-K (PSK) and schizophyllan deserve special attention. These polysaccharides for many years have been successfully applied in cancer treatment and their mechanism of action is the best known.

Evaluation of electrospun (1,3)-(1,6)-β-D-glucans/biodegradable polymer as artificial skin for full-thickness wound healing

(1,3)-(1,6)-β-D-glucan (BG), a natural product of glucose polymers, has immune stimulatory activity that is especially effective in wound healing. In this study, poly(lactic-co-glycolic acid) (PLGA) membranes containing BGs (BG/PLGA membranes) were investigated for their wound-healing effects. The growth rate of human dermal fibroblasts was enhanced in BG/PLGA membranes. Their growth rates were improved with the increase of BG concentration in the membranes. The PLGA membranes with and without BGs were treated in full-thickness skin wound using male BALB/c nude mice (n=6 for each group). According to the animal study, BG/PLGA membranes enhanced the interaction with the surrounding cells in wound sites. In the wound site treated BG/PLGA, the positive of the Ki-67 (a proliferation cell marker) and the CD 31 (an endothelial cell marker) were 77.2%±5.6% and 34±8.6 capillaries. In the wound site treated PLGA, the Ki-67 positive cells were 51.3%±7.0%, and the positive-stained capillaries of CD 31 were 22.7±8.6. The wound site treated with BG/PLGA membranes was stronger stained of them in the wound site than those of the wound sites treated with PLGA membranes. BG/PLGA membranes accelerated wound healing by improving the interaction, proliferation of cells, and angiogenesis. BG/PLGA membranes can be useful as a skin substitute for enhancing wound healing.

β-Glucan treatment prevents progressive burn ischaemia in the zone of stasis and improves burn healing: an experimental study in rats

Saving the zone of stasis is one of the major goals of burn specialists. Increasing the tissue tolerance to ischaemia and inhibiting inflammation have been proposed to enable salvage of this zone. After a burn, excessive inflammation, including increased vascular permeability, local tissue oedema and neutrophil activation, causes local tissue damage by triggering vascular thrombosis and blocking capillaries, resulting in tissue ischaemia and necrosis. Oxygen radicals also contribute to tissue damage after a burn. However, macrophages play a pivotal role in the response to burn. We studied β-glucan because of its many positive systemic effects that are beneficial to burn healing, including immunomodulatory effects, antioxidant effects (free-radical scavenging activity) and effects associated with the reduction of the inflammatory response. There were four test groups in this study with eight rats in each group. Group 1 was the control group, group 2 was administered a local pomade (bacitracin+neomycin sulphate), group 3 received β-glucan (50 mg kg(-1), orally) + the local pomade and group 4 received β-glucan. Burns were created using a brass comb model. Macroscopic, histopathological and statistical assessments were performed. Samples were harvested on the 3rd, 7th and 21 days for analysis. The neutrophilic infiltration into the zone of stasis was analysed on day 3. Macrophage infiltration, fibroblast proliferation, angiogenesis and re-epithelialisation ratios in the zone of stasis were analysed on days 7 and 21. The β-glucan groups (groups 3 and 4) exhibited lower neutrophil counts on the 3rd day, and macrophage infiltration, fibroblast proliferation, angiogenesis and re-epithelialisation were very high in these groups on the 7th day. In particular, re-epithelialisation on the 21st day was significantly better in the β-glucan groups. This study demonstrated that β-glucan may prevent neutrophil-dependent tissue damage and burn-induced oxidative injury through its anti-inflammatory and antioxidant properties. We speculate that the inhibition of neutrophil activation preserves vascular patency by preventing capillary blockage. β-Glucan is also a powerful macrophage stimulator, and is therefore very effective in saving the zone of stasis.

Synthesis of curdlan-graft-poly(ethylene glycol) and formulation of doxorubicin-loaded core–shell nanoparticles

A new core–shell nanoparticle containing the chemotherapeutic drug doxorubicin was formulated via amphiphilic graft copolymer self-assembly using curdlan- graft-poly(ethylene glycol) (curdlan -g-PEG). The graft copolymer was synthesized through the dicyclohexylcarbodiimide ester linkage of carboxylated PEG to the hydroxyl groups of the curdlan backbone. The nanoparticles were 109.9 nm in size and encapsulated doxorubicin in high yield (4%–5% wt/wt). The nanoparticles also controlled the release of doxorubicin over 24 h with a release profile that followed a Fickian diffusion model. The biocompatibility of curdlan- g-PEG was confirmed by hemolysis assay. This is the first nanoparticle formulated using the hydrophobicity of curdlan for concealing the immunomodulatory potential of curdlan within the core.

β-Glucan from Lentinus edodes inhibits nitric oxide and tumor necrosis factor-α production and phosphorylation of mitogen-activated protein kinases in lipopolysaccharide-stimulated murine RAW 264.7 macrophages

Lentinan (LNT), a β-glucan from the fruiting bodies of Lentinus edodes, is well known to have immunomodulatory activity. NO and TNF-α are associated with many inflammatory diseases. In this study, we investigated the effects of LNT extracted by sonication (LNT-S) on the NO and TNF-α production in LPS-stimulated murine RAW 264.7 macrophages. The results suggested that treatment with LNT-S not only resulted in the striking inhibition of TNF-α and NO production in LPS-activated macrophage RAW 264.7 cells, but also the protein expression of inducible NOS (iNOS) and the gene expression of iNOS mRNA and TNF-α mRNA. It is surprising that LNT-S enhanced LPS-induced NF-κB p65 nuclear translocation and NF-κB luciferase activity, but severely inhibited the phosphorylation of JNK1/2 and ERK1/2. The neutralizing antibodies of anti-Dectin-1 and anti-TLR2 hardly affected the inhibition of NO production. All of these results suggested that the suppression of LPS-induced NO and TNF-α production was at least partially attributable to the inhibition of JNK1/2 and ERK1/2 activation. This work discovered a promising molecule to control the diseases associated with overproduction of NO and TNF-α.

Immunomodulatory beta-glucan from Lentinus edodes activates mitogen-activated protein kinases and nuclear factor-kappaB in murine RAW 264.7 macrophages

Lentinan, a cell wall β-glucan from the fruiting bodies of Lentinus edodes, is well known to be a biological defense modifier, but the signal transduction pathway(s) induced by Lentinan have not been elucidated. In this study, we extracted Lentinan (LNT-S) by ultrasonication from Lentinus edodes and report that, in murine RAW 264.7 macrophages, LNT-S glucan activated NF-κB p65 and triggered its nuclear translocation as determined by Western blotting. Moreover, LNT-S enhanced NF-κB-luciferase activity in the Dual-Luciferase gene system assay. Its upstream signaling molecules, MAPKs such as ERK1/2 and JNK1/2, were shown to be activated by assessing the level of phosphorylation in a time- and concentration-dependent manner, but its downstream proinflammatory enzyme, inducible NOS, was not observed. The data evaluated using a TNF-α ELISA kit and Griess reagent further demonstrated that no proinflammatory mediators such as TNF-α and NO were produced by LNT-S stimulation in RAW 264.7 cells. In contrast, LPS significantly induced inducible NOS expression and increased NO and TNF-α production, which are associated with activation of the NF-κB p65/p50 heterodimer complex. It is possible that LNT-S did not activate NF-κB p65/p50, and the activation of NF-κB p65 was not sufficient to stimulate cytokine production. These data demonstrate that LNT-S glucan carries out its immunomodulating activity by activating MAPK signaling pathways without secretion of TNF-α and NO.

Pharmacological, structural, and drug delivery properties and applications of 1,3-β-glucans

1,3-β-Glucans are a class of natural polysaccharides with unique pharmacological properties and the ability to form single- and triple-helical structures that can be formed into resilient gels with the application of heat and humidity. The pharmacological capabilities of 1,3-β-glucans include the impartation of tumor inhibition, resistance to infectious disease, and improvements in wound healing. Curdlan is a linear 1,3-β-glucan that has been used extensively to study the nature of these helical structures and gels, and Curdlan sulfates have found ongoing application in the inhibition of HIV infection. 1,3-β-Glucan gels have been used in food science as stabilizers and encapsulating agents, in nanoscience as scaffolds to build nanofibers and nanowires, and in drug delivery to form nanoparticles and create helical micelles encapsulating polynucleotides. 1,3-β-Glucans are beginning to have enormous significance due to their dual nature as structure-forming agents and pharmacological substances, and research is especially focused on the application of these polymers in animal nutrition and drug delivery.

β-1,3-Glucan-induced host phospholipase D activation is involved in Aspergillus fumigatus internalization into type II human pneumocyte A549 cells

The internalization of Aspergillus fumigatus into lung epithelial cells is a process that depends on host cell actin dynamics. The host membrane phosphatidylcholine cleavage driven by phospholipase D (PLD) is closely related to cellular actin dynamics. However, little is known about the impact of PLD on A. fumigatus internalization into lung epithelial cells. Here, we report that once germinated, A. fumigatus conidia were able to stimulate host PLD activity and internalize more efficiently in A549 cells without altering PLD expression. The internalization of A. fumigatus in A549 cells was suppressed by the downregulation of host cell PLD using chemical inhibitors or siRNA interference. The heat-killed swollen conidia, but not the resting conidia, were able to activate host PLD. Further, β-1,3-glucan, the core component of the conidial cell wall, stimulated host PLD activity. This PLD activation and conidia internalization were inhibited by anti-dectin-1 antibody. Indeed, dectin-1, a β-1,3-glucan receptor, was expressed in A549 cells, and its expression profile was not altered by conidial stimulation. Finally, host cell PLD1 and PLD2 accompanied A. fumigatus conidia during internalization. Our data indicate that host cell PLD activity induced by β-1,3-glucan on the surface of germinated conidia is important for the efficient internalization of A. fumigatus into A549 lung epithelial cells.

Probing β-(1→3)-D-glucans interactions with recombinant human receptors using high-resolution NMR studies

A full characterization of the high-resolution NMR spectrum of the laminarihexaose is described and used for the determination of the binding epitope of the more complex but structurally related laminarin. These biophysical data extend the current knowledge of β-glucans/Dectin-1 interactions and suggest different biological mechanisms in close relation with the size of the saccharidic chain.

Interaction of two phagocytic host defense systems: Fcγ receptors and complement receptor 3

Phagocytosis of foreign pathogens by cells of the immune system is a vitally important function of innate immunity. The phagocytic response is initiated when ligands on the surface of invading microorganisms come in contact with receptors on the surface of phagocytic cells such as neutrophils, monocytes/macrophages, and dendritic cells. The complement receptor CR3 (CD11b/CD18, Mac-1) mediates the phagocytosis of complement protein (C3bi)-coated particles. Fcγ receptors (FcγRs) bind IgG-opsonized particles and provide a mechanism for immune clearance and phagocytosis of IgG-coated particles. We have observed that stimulation of FcγRs modulates CR3-mediated phagocytosis and that FcγRIIA and FcγRI exert opposite (stimulatory and inhibitory) effects. We have also determined that an intact FcγR immunoreceptor tyrosine-based activation motif is required for these effects, and we have investigated the involvement of downstream effectors. The ability to up-regulate or down-regulate CR3 signaling has important implications for therapeutics in disorders involving the host defense system.

Does the Agaricus blazei Murill mushroom have properties that affect the immune system? An integrative review

There has been a significant increase in the use of mushrooms for therapeutic and medicinal purposes, in particular, use of the species Agaricus blazei Murrill, a basidiomycota of Brazilian origin. The objective of this study was to identify scientific evidence regarding the influence of A. blazei Murrill on the immune system. We undertook an integrative review of indexed publications published between 2000 and 2009, using the following question as a guideline: "What evidence can be found in the literature regarding the influence of A. blazei Murrill on the immune system?" Fourteen studies verified that there is in vitro and in vivo research demonstrating this mushroom's influence on the immune system. All research was characterized as evidence level 7 (preclinical study [animals/in vitro]). The research shows that A. blazei Murrill functions through bioactive compounds via mechanisms that are not yet entirely clear, although it has been shown that they promote action on the innate and adaptive immunological response, activation of the complement system, and synthesis of pro- and anti-inflammatory cytokines and even aid in diapedesis. Despite broad scientific evidence demonstrating relevant immunomodulatory properties of A. blazei Murrill, randomized clinical trials with human subjects are still needed in order for the mushroom to be put into clinical practice.

Maitake beta-glucan promotes recovery of leukocytes and myeloid cell function in peripheral blood from paclitaxel hematotoxicity

Bone marrow myelotoxicity is a major limitation of chemotherapy. While granulocyte colony stimulating factor (G-CSF) treatment is effective, alternative approaches to support hematopoietic recovery are sought. We previously found that a beta-glucan extract from maitake mushroom Grifola frondosa (MBG) enhanced colony forming unit-granulocyte monocyte (CFU-GM) activity of mouse bone marrow and human hematopoietic progenitor cells (HPC), stimulated G-CSF production and spared HPC from doxorubicin toxicity in vitro. This investigation assessed the effects of MBG on leukocyte recovery and granulocyte/monocyte function in vivo after dose intensive paclitaxel (Ptx) in a normal mouse. After a cumulative dose of Ptx (90-120 mg/kg) given to B6D2F1mice, daily oral MBG (4 or 6 mg/kg), intravenous G-CSF (80 microg/kg) or Ptx alone were compared for effects on the dynamics of leukocyte recovery in blood, CFU-GM activity in bone marrow and spleen, and granulocyte/monocyte production of reactive oxygen species (ROS). Leukocyte counts declined less in Ptx + MBG mice compared to Ptx-alone (p = 0.024) or Ptx + G-CSF treatment (p = 0.031). Lymphocyte levels were higher after Ptx + MBG but not Ptx + G-CSF treatment compared to Ptx alone (p < 0.01). MBG increased CFU-GM activity in bone marrow and spleen (p < 0.001, p = 0.002) 2 days after Ptx. After two additional days (Ptx post-day 4), MBG restored granulocyte/monocyte ROS response to normal levels compared to Ptx-alone and increased ROS response compared to Ptx-alone or Ptx + G-CSF (p < 0.01, both). The studies indicate that oral MBG promoted maturation of HPC to become functionally active myeloid cells and enhanced peripheral blood leukocyte recovery after chemotoxic bone marrow injury.

Immunomodulatory activities and subacute toxicity of a novel β-glucan from Paenibacillus polymyxa JB115 in rats

Subacute toxicity and immunopharmacological activities of β-glucan from P. polymyxa JB115 was evaluated in a 28-day feeding study in rats. The white blood cell count, red blood cell count, hematocrit, hemoglobin, thrombocytes (THR) and thrombocytocrit were significantly higher in male fed with β-glucan than control rats and the insignificant lower eosinophil count, mean corpuscular volume, mean cell hemoglobin and uninfected THR (uTHR) levels were observed in male whereas no marked changes in female rats. No other significant differences in serum chemistry and liver, kidney, and spleen weights were observed. The pathological changes and other abnormal indicators were not detected in urine. Female rats fed with diet supplemented with 0.01% β-glucan also showed marked increase in the percentage of blood cytotoxic T-lymphocytes compared to that of the control group while not significant differences in the percentage of blood B-lymphocytes. No adverse effects on general condition and behavior, growth, feed and water consumption and feed conversion efficiency were found. The results suggest that consumption of the novel β-1, 3/1, 6-glucan from P. polymyxa JB115 was not associated with any obvious toxic effects in rats, indicating its safety as a potential immunostimulant or as an adjuvant of some animal vaccines.

Commandeering a biological pathway using aptamer-derived molecular adaptors

Induction of molecular proximity can mediate a discrete functional response in biological systems. Therefore, creating new and specific connectivity between non-interacting proteins is a means of imposing rational control over biological processes. According to this principle, here we use composite RNA aptamers to generate molecular adaptors that link various ‘target’ molecules to a common ‘utility’ molecule, with the utility molecule being an entry point to a pathway conscripted to process the target molecule. In particular, we created a bi-functional aptamer that simultaneously binds to the green fluorescent protein (serving as a surrogate extracellular target) and the opsonin C3b/iC3b (serving as the utility molecule). This bi-functional aptamer enabled us to commandeer the C3-based opsonization-phagocytosis pathway to selectively transport an extracellular target into the lysosome for degradation. This novel strategy has the potential for powerful therapeutic applications with extracellular proteins involved in tumor development or surface markers on cancer cells as the target molecules.

Effects of Agaricus brasiliensis mushroom in Walker-256 tumor-bearing rats

Agaricus brasiliensis is a mushroom native to São Paulo State, Brazil, that is studied for its medicinal proprieties. This work aimed to investigate the antitumoral activity of A. brasiliensis extracts and pure powdered basidiocarp preparation using Walker-256 (W256) tumor-bearing rats, a model for cancer-related cachexia studies. The rats were treated for 14 days by gavage (136 mg/kg) and at the end of the experiment tumors were collected to calculate mass and volume. Blood was collected for determination of plasma glucose, albumin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Hepatic and tumor enzymes indicating oxidative stress were also evaluated. The results showed that all 4 treatments (pure powdered basidiocarp and aqueous, acid, and alkaline extracts) significantly reduced tumor size and promoted gain in body weight. Plasmatic analysis showed a reduction in AST level and increased glycemia in the treated rats. Pure basidiocarp preparations improved the liver catalase and superoxide dismutase activity, but did not change the glutathione S-transferase activity. The data collected from the W256 tumor-bearing rats revealed the beneficial effects of A. brasiliensis in tumor treatment, mainly related to cachexia. The benefits can be partly related to antioxidant activity and to reduction of weight loss and tumor growth.

The amplification loop of the complement pathways

The C3 amplification loop lies at the core of all the complement pathways, rather than the alternative pathway alone. It is, in evolutionary terms, the oldest part of the complement system and its antecedents can be seen in insects and in echinoderms. The amplification loop is the balance between two competing cycles both acting on C3b: the C3 feedback cycle which enhances amplification and the C3 breakdown cycle which downregulates it. It is solely the balance between their rates of reaction on which amplification depends. The C3 breakdown cycle generates iC3b as its primary reaction product. iC3b, through its reaction with the leukocyte integrins (and complement receptors) CR3 (CD11b/CD18) and CR4 (CD11c/CD18), is the most important mechanism by which complement mediates inflammation. A variety of genetic polymorphisms in components of the amplification loop have been shown to predispose to two kidney diseases-dense deposit disease and atypical haemolytic uraemic syndrome-and to age-related macular degeneration. All predisposing alleles enhance amplification, whereas protective alleles downregulate amplification. This leads to the conclusion that there is a "hyperinflammatory complement phenotype" determined by these polymorphisms. This hyperinflammatory phenotype protects against bacterial infections in early life but in later life is associated with immunopathology. Besides the diseases already mentioned, there is evidence that this hyperinflammatory complement phenotype may predispose to accelerated atherosclerosis and also shows an association with Alzheimer's disease. Downregulation of the amplification loop therefore constitutes an important therapeutic target.

Glucans from the Caripia montagnei mushroom present anti-inflammatory activity

Caripia montagnei is a basidiomycete species which contains polysaccharides with immunomodulatory properties. An extract of this mushroom underwent removal of the fat content by organic solvent and subsequently proteolysis. The aqueous phase obtained after proteolysis was precipitated with methanol yielding a fraction containing carbohydrates (98.7+/-3.3%) and protein (1.3+/-0.25%). Chemical analysis, infrared spectroscopy and nuclear magnetic resonance (NMR) showed that the carbohydrate fraction contained (63.3+/-4.1) of beta-glucans and proteins (2.2+/-0.3%). These glucans (50mg/kg of body weight) significantly reduced the inflammatory infiltrate produced by thioglycolate-induced peritonitis by 75.5+/-5.2%, when compared to Wy-14643 (60.3+/-6.1%), PFOA (37.8+/-2.8%) and clofibrate (52.2+/-3.2%), p<0.001, which are of the peroxisome proliferator-activated receptor (PPAR-alpha). L-NAME, a nitric oxide synthase inhibitor, reduced the plantar edema in Wistar rats by 91.4+/-1.3% (p<0.001). A significant reduction in nitric oxide (NO) levels was observed in the exudates when the glucans was used in comparison to carrageenan. The C. montagnei glucans did not present signs of inducing cytotoxicity. A decrease in IL-1ra, IL-10 and IFN-gamma in the peritonitis model was observed. Thus, the results suggest that glucans from the C. montagnei mushroom is an effective immunomodulator and may have potential for anti-inflammatory properties.

Hepatoprotective effects of paramylon, a beta-1, 3-D-glucan isolated from Euglena gracilis Z, on acute liver injury induced by carbon tetrachloride in rats

Paramylon is a beta-(1-3)-D-glucan isolated from Euglena gracilis Z. This study was designed to evaluate the protective effects of paramylon on liver injury induced by carbon tetrachloride (CCl(4)) in rats. Wistar stain male rats were orally administered paramylon (500, 1,000 and 2,000 mg/kg body weight) before treatment with a single intraperitoneal dose of 50% CCl(4) (2 ml/kg body weight). The rats were sacrificed 24 hr later, and blood samples were collected for assay of serum biochemical parameters. The livers were excised to evaluate the activity of antioxidant enzymes. Histopathological examination of the livers was also performed. The results showed that the treatment of paramylon prevented elevation of the serum levels of hepatic enzyme markers and inhibited fatty degeneration and hepatic necrosis induced by CCl(4). Pre-administration of paramylon reduced the liver apoptotic index. The treatment of paramylon recovered reductions of activity of hepatic superoxide dismutase, catalase and glutathione peroxidase induced by CCl(4). These results demonstrate that paramylon exhibits protective action on acute hepatic injury induced by CCl(4) via an antioxidative mechanism. To the best of our knowledge, this is the first report of a hepatoprotective effect based on the antioxidative action of paramylon.

A novel beta-glucan produced by Paenibacillus polymyxa JB115 induces nitric oxide production in RAW264.7 macrophages

The effect of extracellular β-(1→3), (1→6)-glucan, produced by Paenibacillus polymyxa JB115, on nitric oxide (NO) production in RAW264.7 macrophages was investigated. β-glucan induced the production of NO by RAW264.7 macrophages in a concentration- and time-dependent manner. Moreover, β-glucan stimulation increased the mRNA expression of iNOS, COX-2 and IL-6 in RAW264.7 macrophages in a concentration-dependent manner.

Protective effects of betaglucin on myocardial tissue during myocardial infarction in rats and dogs

AIM

To test the protective effects of betaglucin, a novel beta-glucan, on models of myocardial infarction (MI) in rats and dogs.

METHODS

The left anterior descending (LAD) coronary artery occlusion model was used to induce an MI in rats and dogs. Three doses of betaglucin (10, 30 and 100 mg/kg), propranolol (positive control, 1 mg/kg) and vehicle alone (5% glucose solution) were administered before LAD occlusion, and characteristics of the resulting MI were subsequently assessed. In anesthetized dogs, blood pressure, heart rate, ventricular function, coronary artery blood flow and myocardial oxygen consumption were determined before and after the drug administration.

RESULTS

The MI mass in both rats and dogs was significantly reduced by betaglucin (30 and 100 mg/kg, P<0.01) and propranolol (P<0.01). In anesthetized dogs, coronary artery blood flow was increased significantly by betaglucin (30 and 100 mg/kg, P<0.01), but blood pressure, heart rate and ventricular function were not changed (P>0.05). High-dose betaglucin (100 mg/kg) increased myocardial oxygen consumption, but not to a statistically significant level (P>0.05). The hemodynamic indexes were significantly changed by propranolol.

CONCLUSION

Betaglucin has protective effects on myocardial tissue during MI in rats and dogs and has no influence on hemodynamic parameters at a therapeutic dose. The increase in coronary artery blood flow induced by betaglucin might be beneficial in the treatment of patients with MI.

Glucan and Glutamine Reduce Bacterial Translocation in Rats Subjected to Intestinal Ischemia–Reperfusion

Intestinal ischemia/reperfusion (I/R) may induce bacterial translocation (BT). Glutamine (GLN)-enriched nutrition decreases BT. However, little is known about the effect of glucan (GL) in BT. This study investigated the combined effect of GL/GLN on BT, intestinal damage, and portal blood cytokines in animals under I/R. Four groups of 10 rats each were subjected to 60 min of intestinal ischemia and 120 min of reperfusion. The control group (group 1) received only rat food/water, group 2 received glutamine via gavage, group 3 received subcutaneuos soluble (1, 3)-d-glucan, and group 4 received GL + GLN. A sham group (group 5) served as a normal control. Bacterial cultures of ileum, mesenteric lymph nodes (MLN), liver and lung biopsies, histological changes of ileum, and serum cytokines variables were examined after I/R. Data were analyzed by analysis of variance (ANOVA) and the Newman-Keuls test. Results showed that GLN, GL, and GL/GLN significantly reduced BT to MLN, liver, and lung. BT was more attenuated after GL treatment than GLN (P < .05). Rats treated with both GL and GLN exhibited lower bacterial colony counts than the ones treated only with GLN or GL. Severe mucosal damage on histological findings was shown in group 1, but these findings were significantly ameliorated (P < .05) in groups 3 and 4. Tumor necrosis factor (TNF)-a and interleukin (IL)-6 levels in portal serum were significantly reduced and IL-10 was increased by GL and GLN treatment. In conclusion, the use of GL was more effective than GLN in reducing BT, intestinal damage, and cytokine levels after I/R. Additionally, the combination of GL and GLN improved results.