The effect of (1-->3)-beta-D-glucans, carboxymethylglucan and schizophyllan on human leukocytes in vitro

Preparation of β-1,3-glucan mimics via modification of polymer backbone, and evaluation of cytokine production using the polymer library in immune activation

β-1,3-Glucans possess therapeutic potential owing to their ability to exhibit immunostimulating activity. β-1,3-Glucans, isolated from various organisms, differ in their chemical structures, molecular weight, and branching degree, potentially forming particulate, helix, or random coil conformations in water. Therefore, this study used synthesized β-1,3-glucan mimic polymers to investigate the difference in binding affinity for dectin-1 and induced cytokine productions based on polymer structures. The β-1,3-glucan mimic polymers were synthesized using β-1,3-glucan tetrasaccharyl monomer, with subsequent modifications to the polymer backbones through the introduction of hydrogen or a hydroxy group. Polymers with different structures in both ligands and polymer backbones were utilized to comprehensively investigate their binding affinity to dectin-1 and cytokine-inducing in macrophages. Hydroxylated polymers exhibited a high binding affinity for dectin-1, similar to that of schizophyllan, whereas the polymer composed of only saccharyl monomers did not bind to dectin-1. Further, when administered to macrophage RAW264 cells, polymers with branched and hydrophobic polymer backbones exhibited strong cytokine-inducing activities. Moreover, the results revealed that the essential factors for cytokine induction include the branches of β-1,3-glucans, high (tens of thousands) molecular weights, and hydrophobicity. The results suggests that artificial polymers comprising these factors exhibit immunostimulating activity and could be developed as therapeutic agents.

β-Glucan as a Techno-Functional Ingredient in Dairy and Milk-Based Products—A review

The article systematizes information about the sources of β-glucan, its technological functions and practical aspects of its use in dairy and milk-based products. According to the analysis of scientific information, the main characteristics of β-glucan classifications were considered: the source of origin, chemical structure, and methods of obtention. It has been established that the most popular in the food technology of dairy products are β-glucans from oat and barley cereal, which exhibit pronounced technological functions in the composition of dairy products (gel formation, high moisture-binding capacity, increased yield of finished products, formation of texture, and original sensory indicators). The expediency of using β-glucan from yeast and mushrooms as a source of biologically active substances that ensure the functional orientation of the finished product has been revealed. For the first time, information on the use of β-glucan of various origins in the most common groups of dairy and milk-based products has been systematized. The analytical review has scientific and practical significance for scientists and specialists in the field of food production, in particular dairy products of increased nutritional value.

Oral administration of botryosphaeran [(1 → 3)(1 → 6)-β-d-glucan] reduces inflammation through modulation of leukocytes and has limited effect on inflammatory nociception

Several biological activities of the fungal exopolysaccharide (1 → 3)(1 → 6)-β-d-glucan (botryosphaeran) have been described in the literature, but its effects on inflammation have not been evaluated. This study aimed to investigate the action of botryosphaeran on experimental mice models of carrageenan-induced acute pleurisy and acute paw edema, and complete Freund's adjuvant-induced persistent paw edema. All botryosphaeran doses tested (1.0, 2.5, 5.0, and 10.0 mg/kg birth weight [b.w.], orally administered) reduced leukocyte recruitment, nitric oxide (NO) levels, and protein extravasation in the pleural cavity. Botryosphaeran (5 mg/kg b.w.) did not diminish edema and mechanical hyperalgesia in the paw within 4 h; however, cold allodynia was alleviated within the first 2 h. In the persistent paw inflammation model, the effects of daily oral administration of botryosphaeran (5 mg/kg b.w.) were evaluated over 3 and 7 days. The fungal β-glucan significantly reduced the levels of the cytokines, tumor necrosis factor(TNF)-α, interleukin (IL)-6), and IL-10, in the paw homogenates in both protocols, while paw edema and the levels of advanced oxidation protein products (AOPP) only diminished on Day 7. No effect in mechanical hyperalgesia was observed. Oral treatment for 3 or 7 days also decreased the plasma levels of NO, AOPP, TNF-α, and IL-10. On Day 7, the number of leukocytes in the blood was also reduced by this treatment. Importantly, botryosphaeran did not induce inflammation in mice when administered alone over 7 days. This study demonstrated the anti-inflammatory and antinociceptive potential of botryosphaeran in these experimental models, making this fungal β-glucan a new possibility for complementary treating acute and chronic inflammation.

Saccharomyces cerevisiae Dehydrated Culture Modulates Fecal Microbiota and Improves Innate Immunity of Adult Dogs

Saccharomyces cerevisiae yeast culture can be dehydrated, and it has a potential prebiotic effect. This study evaluated the effects of supplementing increasing levels of dehydrated yeast culture (DYC) of Saccharomyces cerevisiae (Original XPC™, Diamond V, Cedar Rapids, IA, USA) on fecal microbiota, nutrient digestibility, and fermentative and immunological parameters of healthy adult dogs. Eighteen adult male and female dogs with a mean body weight of 15.8 ± 7.37 kg were randomly assigned to three experimental treatments: CD (control diet), DYC 0.3 (control diet with 0.3% DYC) and DYC 0.6 (control diet with 0.6% DYC). After 21 days of acclimation, fecal samples were collected for analysis of nutrient digestibility, microbiota and fecal fermentation products. On the last day, the blood samples were collected for the analysis of immunological parameters. The microbiome profile was assessed by the Illumina sequencing method, which allowed identifying the population of each bacterial phylum and genus. The statistical analyses were performed using the SAS software and the Tukey test for multiple comparison (p < 0.05). Our results suggest that the addition of DYC increased the percentage of the phyla Actinobacteria and Firmicutes (p = 0.0048 and p < 0.0001, respectively) and reduced that of the phylum Fusobacteria (p = 0.0008). Regardless of the inclusion level, the yeast addition promoted reduction of the genera Allobaculum and Fusobacterium (p = 0.0265 and p = 0.0006, respectively) and increased (p = 0.0059) that of the genus Clostridium. At the highest prebiotic inclusion level (DYC 0.6), an increase (p = 0.0052) in the genus Collinsella and decrease (p = 0.0003) in Prevotella were observed. Besides that, the inclusion of the additive improved the apparent digestibility of the crude fiber and decreased the digestibility of crude protein, nitrogen-free extract and metabolizable energy (p < 0.05). There were no significant changes in the production of volatile organic compounds. However, an increase in propionate production was observed (p = 0.05). In addition, the inclusion of yeast resulted in an increased phagocytosis index in both treatments (p = 0.01). The addition of 0.3 and 0.6% DYC to the diet of dogs wase able to modulate the proportions of some phyla and genera in healthy dogs, in addition to yielding changes in nutrient digestibility, fermentative products and immunity in healthy adult dogs, indicating that this additive can modulate fecal microbiota and be included in dog nutrition.

Enhanced exopolysaccharide yield and antioxidant activities of Schizophyllum commune fermented products by the addition of Radix Puerariae

To increase the production of exopolysaccharides (EPS) and expand the application of Schizophyllum commune (S. commune) fermentation liquid, the traditional Chinese medicine Radix Puerariae (RP) with outstanding biological activity was selected as a culture additive to improve the EPS yield and enhance the antioxidant activity of fermented products from S. commune. The effects of three independent factors: A: initial pH (5.0-6.0), B: concentration of RP (10-14 g L-1), and C: inoculum size (8-12%, v/v) on the EPS yield were evaluated. The results of response surface methodology (RSM) showed that the optimal fermentation conditions were: A: 5.40, B: 12.80 g L-1, and C: 10.0%. The optimal yield of EPS was 8.41 ± 0.12 mg mL-1, which showed an insignificant (p > 0.05) difference with the predicted value (8.45 mg mL-1). The fermented supernatants cultured from RP-supplemented medium (SC-RP) or regular medium (SC) were collected for further study. FT-IR analysis of EPS-1 (purified from SC) and EPS-2 (purified from SC-RP) showed that their structures were consistent, indicating that the addition of RP did not affect the structure of schizophyllan (SPG). In addition, compared with SC, the in vitro antioxidant activities of SC-RP were significantly improved with ORAC values and FRAP values increasing by 11.56-fold and 14.69-fold, respectively. There was a significant correlation among the phenolic compounds, flavonoids, and antioxidant activity of SC-RP in this study. Besides, SC-RP was detected to contain more than 25 bioactive ingredients compared with that of SC, which may play a key role in its antioxidant activities. Thus, these results indicated that RP enhanced the yield of SPG and improved the antioxidant activity of the fermented products by S. commune. Accordingly, the fermentation liquid of S. commune with the addition of RP may have potential application in food, cosmetics, and pharmaceutical industries.

Cytotoxicity activities and chemical characteristics of exopolysaccharides and intracellular polysaccharides of Physarum polycephalum microplasmodia

BACKGROUND

Microbial polysaccharides have been reported to possess remarkable bioactivities. Physarum polycephalum is a species of slime mold for which the microplasmodia are capable of rapid growth and can produce a significant amount of cell wall-less biomass. There has been a limited understanding of the polysaccharides produced by microplasmodia of slime molds, including P. polycephalum. Thus, the primary objectives of this research were first to chemically characterize the exopolysaccharides (EPS) and intracellular polysaccharides (IPS) of P. polycephalum microplasmodia and then to evaluate their cytotoxicity against several cancer cell lines.

RESULTS

The yields of the crude EPS (4.43 ± 0.44 g/l) and partially purified (deproteinated) EPS (2.95 ± 0.85 g/l) were comparable (p > 0.05) with the respective crude IPS (3.46 ± 0.36 g/l) and partially purified IPS (2.45 ± 0.36 g/l). The average molecular weight of the EPS and IPS were 14,762 kDa and 1788 kDa. The major monomer of the EPS was galactose (80.22%), while that of the IPS was glucose (84.46%). Both crude and purified IPS samples showed significantly higher cytotoxicity toward Hela cells, especially the purified sample and none of the IPSs inhibited normal cells. Only 38.42 ± 2.84% Hela cells remained viable when treated with the partially purified IPS (1 mg/ml). However, although only 34.76 ± 6.58% MCF-7 cells were viable when exposed to the crude IPS, but the partially purified IPS displayed non-toxicity to MCF-7 cells. This suggested that the cytotoxicity toward MCF-7 would come from some component associated with the crude IPS sample (e.g. proteins, peptides or ion metals) and the purification process would have either completely removed or reduced amount of that component. Cell cycle analysis by flow cytometry suggested that the mechanism of the toxicity of the crude IPS toward MCF-7 and the partially purified IPS toward Hela cells was due to apoptosis.

CONCLUSIONS

The EPS and IPS of P. polycephalum microplasmodia had different chemical properties including carbohydrate, protein and total sulfate group contents, monosaccharide composition and molecular weights, which led to different cytotoxicity activities. The crude and partially purified IPSs would be potential materials for further study relating to cancer treatment.

Potential benefit of β-glucans as adjuvant therapy in immuno-oncology: a review

Fungal compounds have long been used for centuries as food supplements. β-glucans have been identified as the most interesting molecules with beneficial effects in several chronic diseases. In vitro studies have shown that they are able to elicit the immune cells maturation and activation with the result of an increased release of proinflammatory cytokines and chemokines and a stimulation of anti-bacterial activity of macrophages and neutrophils. As β-glucans enhance pathogen elimination through non-self antigens identification, they can also direct immune response against tumor cells. These compounds also stimulate the activity on adaptive immune cells and they have been regarded as biological response modifiers. In this way, β-glucans can be exploited as adjuvant cancer therapy, in particular by a synergic action with chemotherapy or immunotherapy. In the immuno-oncology era, the need is to identify innovative drugs that can simultaneously target and inhibit different biological processes relevant for cancer cells survivors. Recent clinical studies showed promising results about the combination of β-glucans and immune checkpoint inhibitors for patients affected by different solid tumors. This review aims to investigate molecular mechanisms of action of β-glucans and is focused on their application in clinical practice as immune-adjuvants for treatment of cancer patients.

Anti-neoplastic Potential of Flavonoids and Polysaccharide Phytochemicals in Glioblastoma

Clinically, gliomas are classified into four grades, with grade IV glioblastoma multiforme being the most malignant and deadly, which accounts for 50% of all gliomas. Characteristically, glioblastoma involves the aggressive proliferation of cells and invasion of normal brain tissue, outcomes as poor patient prognosis. With the current standard therapy of glioblastoma; surgical resection and radiotherapy followed by adjuvant chemotherapy with temozolomide, it remains fatal, because of the development of drug resistance, tumor recurrence, and metastasis. Therefore, the need for the effective therapeutic option for glioblastoma remains elusive. Previous studies have demonstrated the chemopreventive role of naturally occurring pharmacological agents through preventing or reversing the initiation phase of carcinogenesis or arresting the cancer progression phase. In this review, we discuss the role of natural phytochemicals in the amelioration of glioblastoma, with the aim to improve therapeutic outcomes, and minimize the adverse side effects to improve patient's prognosis and enhancing their quality of life.

Renewable sources: applications in personal care formulations

A global tendency for products considered environmentally sustainable, and ecologically obtained led the industry related to personal care formulations to fund the research and the development of personal care/cosmetics containing ingredients from natural resources. Furthermore, consumers are aware of environmental and sustainability issueans, thus not harming the environment represents a key consideration when developing a new cosmetic ingredient. In this study we review some examples of active ingredients or raw materials used in cosmetics/personal care/biomedical products that are coming from either through biotechnological systems, or as byproducts of several industries. A skin formulation containing biosynthetic actives, prepared by us and the study regarding its dermocosmetic properties are also described. The need for the standardization processes, the safety assessment tools, the improvement of the exploitation methods of these renewable sources in order the production to be ecologically and economically better are also discussed.

Schizophyllum commune induces IL-17-mediated neutrophilic airway inflammation in OVA-induced asthma model mice

Schizophyllum commune is a ubiquitous basidiomycetous fungus typically found across the world, which has been detected in indoor and outdoor air. Some studies indicated that sensitization to S. commune is correlated with asthma severity in patients. Patients with chronic severe or acute fatal asthma have neutrophil-dominant airway inflammation. We hypothesized that S. commune can exacerbate asthma. To test this hypothesis, we evaluated the direct immunomodulatory activities of S. commune in allergic airway inflammation induced by non-fungal sensitization. Ovalbumin (OVA)-induced asthma model mice were generated using wild-type (WT) and Il-17a^-/-Il-17f^-/- mice that were intratracheally exposed to S. commune, then immune responses in the lungs were assessed after 24 h. Intratracheal administration of S. commune in OVA-induced asthma model mice enhanced neutrophilic airway inflammation, increased the mRNA expression of CXCL1 and CXCL2 in the lungs, and provoked IL-17A, and IL-17F production in BAL fluid. In addition, neutrophilic airway inflammation was significantly inhibited in Il-17a^-/-Il-17f^-/- mice compared with those found in WT mice. We demonstrated that S. commune induces neutrophilic airway inflammation in OVA-induced asthma model mice, and IL-17A and IL-17F had central roles in this activity. As S. commune inhabits the general environment, including indoor and outdoor air, our results suggested that S. commune is a causative agent of asthma exacerbation. This study has provided clues regarding the mechanisms behind fungi and asthma exacerbation.

Chromoblastomycosis: an etiological, epidemiological, clinical, diagnostic, and treatment update

Chromoblastomycosis is a chronic, granulomatous, suppurative mycosis of the skin and subcutaneous tissue caused by traumatic inoculation of dematiaceous fungi of the family Herpotrichiellaceae. The species Fonsecaea pedrosoi and Cladophialophora carrionii are prevalent in regions where the disease is endemic. Chromoblastomycosis lesions are polymorphous: verrucous, nodular, tumoral, plaque-like, and atrophic. It is an occupational disease that predominates in tropical and subtropical regions, but there have been several reports of cases in temperate regions. The disease mainly affects current or former farm workers, mostly males, and often leaving disabling sequelae. This mycosis is still a therapeutic challenge due to frequent recurrence of lesions. Patients with extensive lesions require a combination of pharmacological and physical therapies. The article provides an update of epidemiological, clinical, diagnostic, and therapeutic features.

Is Endotoxemia in Stable Hemodialysis Patients an Artefact? Limitations of the Limulus Amebocyte Lysate Assay and Role of (1→3)-β-D Glucan

Background

Elevated blood endotoxin levels are frequently reported in the dialysis population and are strongly linked with inflammation, a major predictor of mortality. Virtually all studies have employed the Limulus Amoebocyte Lysate (LAL) assay to detect endotoxin. However this assay is not endotoxin-specific and can be activated by (1→3)-β-glucan (BG), a component of fungal cell walls leading to false positive signals. Very few studies have taken account of this. We examined the influence of BG-based activation of the LAL assay on the detection of endotoxemia in this setting.

Method

We measured plasma endotoxin levels in 50 hemodialysis patients with and without the use of BG-blocking buffers. These buffers inhibit BG activation of the LAL assay to ensure that any signal detected is endotoxin-specific. Blood samples were measured for BG, interleukin-6 (IL-6), tumor necrosis factor-alfa (TNF-α) to examine the association between endotoxin signals, BG and inflammation.

Results

Endotoxin signals were detected in 50% of patients. On repeat measurement with a BG-blocking buffer, all detected endotoxin signals were extinguished. No patient had detectable endotoxemia. Plasma BG levels were significantly elevated in 58% of patients and were higher in those with detectable endotoxin signals using the LAL assay without BG-blocking buffers (78vs.54pg/mL;p<0.001). Endotoxin signal and BG levels did not correlate with levels of TNF-α or IL-6.

Conclusion

Use of the LAL assay for blood endotoxin detection in dialysis patients has its limitations due to high blood BG. Endotoxemia frequently reported in non-infected hemodialysis patients may be artefactual due to BG interference.

The effect of low or high molecular weight oat beta-glucans on the inflammatory and oxidative stress status in the colon of rats with LPS-induced enteritis

PURPOSE

The aim of the study was to investigate the protective effect of low and high molecular weight beta-glucans on the chosen immunological parameters, markers of antioxidative potential in rats' colon tissue, the number of lactic acid bacteria (LAB) and the concentration of short-chain fatty acids (SCFA) in rats' faeces.

METHODS

The experiment was carried out on 72 8-week old male Sprague-Dawley rats: control (n = 36) and experimental (n = 36). In half of the animals from each group enteritis was induced by LPS (10 mg kg(-1)). Rats from the experimental group were divided into two groups receiving high (GI) or low (GII) molecular weight beta-glucans for 6 consecutive weeks.

RESULTS

LPS evoked enteritis in all the treated animals, manifested by changes in the levels of IL-10, IL-12 and TNF-alpha, as well as in the number of intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) in the colon tissue. Dietary supplementation with beta-glucans following LPS treatment partially reversed this effect. The changes in SCFA concentration were noted, indicating an improvement of the fermentation process in the colon. This effect coincided with an increased number of LAB, pointing at the prebiotic properties of beta-glucans. The positive influence of beta-glucans was also manifested by the improved values of antioxidative potential markers (TAS, SOD, GR and GPx activity, TBARS concentration), noted especially in rats with LPS-induced enteritis. This influence was more pronounced in the case of low molecular weight oat beta-glucan (GII).

CONCLUSIONS

The present study showed a positive effect of beta-glucans, especially the low molecular weight form, on the colon tissue of healthy rats, as well as animals with LPS-induced enteritis.

Oral Intake of Carboxymethyl-Glucan (CM-G) from Yeast (Saccharomyces uvarum) Reduces Malondialdehyde Levels in Healthy Men

Carboxymethyl-glucan (CM-G) is a water-soluble derivative of β(1→3)(1→6) glucan, a well-known immunostimulant and antioxidant compound. In this experimental, randomized and placebo-controlled study, the effects of oral CM-G intake over a 60-day period on the peripheral blood, cholesterol, glycemic index and malondialdehyde (MDA) levels of healthy men was assessed. The CM-G was obtained from spent brewer’s yeast (S. uvarum) with DS 0.8 and molecular weight of 2.2 × 10⁵ Da. Following CM-G administration, no changes were observed in red and white blood cell, hematocrit, hemoglobin and platelet counts, or in cholesterol and glycemic indices. After 30 days of CM-G administration, the MDA levels decreased significantly (p ≤ 0.05) in men receiving CM-G. The results showed for the first time that CM-G may act as an adjuvant in preventing oxidative damage in healthy humans.

Oral Administration of MBG to Modulate Immune Responses and Suppress OVA-Sensitized Allergy in a Murine Model

Recently studies performed on mushroom isolated polysaccharides demonstrated that β -(1,3)-glucan may affect the balance of Th1/Th2 cell response. Using ovalbumin (OVA) as a hypersensitivity inducer, we evaluated the ability of mushroom beta-glucan (MBG) in modulating Th1/Th2 cell responses in B6 mice. As compared to the control group, administration of MBG resulted in an increase of phagocytic activities, Th1 cytokine productions, immunoglobulins including IgG2A and IgA, and a significant expression of the splenic surface markers including CD3, CD4, CD8, and F4/80. In contrast, administration of MBG has significantly suppressed IgE and IgG1 levels and Th2 cytokines including IL-4, IL-5, and IL-6. Histopathological observation of MBG-treated followed by OVA-treated mice showed less filtration of eosinophil in pulmonary tissue sections. Our data suggested that administration of MBG treatments alters the natural course of the IgE-mediated hypersensitivities. In this investigation, we realize the mushroom beta glucan alter the Th2 response toward the Th1 in the allergic, resulting in a reduction in IgE productions which played a substantive role in reducing the severity of IgE-mediated hypersensitivity.

Novel genistein derivatives induce cell death and cell cycle arrest through different mechanisms

Genistein is a natural compound belonging to isoflavone family of secondary plant metabolites, characterized by pleiotropic biological activity. Here we present the results of a study on new analogs and polysaccharide complexes of genistein as potent antiproliferative and cell death-inducing agents. Most potent were 2 analogs (i.e., IFG-027 and IFG-043) and 2 complexes (i.e., SPG-G and XG-G), which had higher or similar antiproliferative activity in comparison to genistein. However, these 2 analogs decreased the number of cells in G2/M phase in contrast to genistein and SPG-G complex. Genistein analogs, IFG-027 and IFG-043, and also SPG-G complex decreased mitochondrial membrane potential and induced the externalization of phosphatidylserine to the extracellular membrane site, which indicates the induction of apoptosis. Interestingly, genistein and its analogs induced caspase 3-activation supporting apoptotic mechanism of cell death but SPG-G supported caspase 3-independent apoptosis. XG-G complex probably did not induce cell death through the apoptotic pathway, as we did not find the externalization of phosphatidylserine and activation of caspase-3. After the treatment of HL-60 cells with genistein, SPG-G and XG-G formation of acidic vesicular organelle (AVO) was detected. In contrast, in the cells that were treated with genistein analogs IFG-027 and IFG-043, AVO formation was not observed.

The isolation and characterization of lipopolysaccharides from Microcystis aeruginosa, a prominent toxic water bloom forming cyanobacteria

Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide, yet serious gaps exist in understanding their complex toxic effects, including the role of lipopolysaccharides (LPS). The present comparative study focused on the levels and biological activities of LPS isolated from Microcystis aeruginosa, which is one of the most globally distributed toxic species. Using hot phenol extraction, LPS was isolated from 3 laboratory cultures and 11 natural water blooms. It formed 0.2-0.7% of the original dry biomass of the cyanobacteria, based on gravimetry. Additional analyses by commercial anti-LPS ELISA were correlated with gravimetry but showed concentrations that were about 7-times lower, which indicated either impurities in isolated LPS or the poor cross-reactivity of the antibodies used. LPS isolates from M. aeruginosa were potent pyrogens in the traditional Limulus amebocyte lysate (LAL)-test, but comparison with the PyroGene test demonstrated the limited selectivity of LAL with several interferences. The determined pyrogenicity (endotoxin units, EU) ranged from very low values in laboratory cultures (less than 0.003 up to 0.008-EU per 100 pg LPS) to higher values in complex bloom samples (0.01-0.078 EU per 100 pg of LPS), which suggested the role of bloom-associated bacteria in the overall effects. Potent pro-inflammatory effects of the studied LPS from both cultures and bloom samples were observed in a highly-relevant ex vivo human blood model by studying reactive oxygen species production in phagocytes as well as increased productions of interleukin 8, IL-8, and tumor necrosis factor α, TNF-α. LPS from M. aeruginosa seem to modulate several pathways involved in the regulation of both innate immunity and specific responses. In comparison to the standard pathogenic bacterial LPS (World Health Organization Escherichia coli O113:10 endotoxin; activity 1 EU per 100 pg), the studied cyanobacterial samples had pyrogenicity potencies that were at least 12-times lower. However, the health risks associated with LPS from M. aeruginosa should not be underestimated, especially with respect to diverse biological effects observed ex vivo and in the case of massive blooms in drinking water reservoirs, where the estimated pyrogenicity can reach up to 46,000 EU per mL of water.

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.

Anticlastogenic effect of β-glucan, extracted from Saccharomyces cerevisiae, on cultured cells exposed to ultraviolet radiation

β-glucan is an important polysaccharide due to its medicinal properties of stimulating the immune system and preventing chronic diseases such as cancer. The aim of the present study was to determine the anticlastogenic effect of β-glucan in cells exposed to ultraviolet radiation (UV). Chromosome aberration assay was performed in drug-metabolizing cells (HTC) and non drug-metabolizing cells (CHO-K1 and repair-deficient CHO-xrs5), using different treatment protocols. Continuous treatment (UV + β-glucan) was not effective in reducing the DNA damage only in CHO-xrs5 cells. However, the pre-treatment protocol (β-glucan before UV exposition) was effective in reducing DNA damage only in CHO-K1 cells. In post-treatment (β-glucan after UV exposition) did not show significative anticlastogenic effects, although there was a tendency toward prevention. The data suggest that β-glucan has more than one action mechanism, being capable of exerting desmutagenic as well as bio-antimutagenic action. The findings also suggest that the presence of the xenobiotic metabolizing system can reduce the chemopreventive capacity of β-glucan. Therefore, these results indicate that β-glucan from Saccharomyces cerevisiae can be used in the prevention and/or reduction of DNA damage.

Comparison of the potency of a variety of β-glucans to induce cytokine production in human whole blood

β-Glucans are components of fungal cell walls and potent stimulants of innate immunity. The majority of research on biological activities of glucans has focused on β-(1→3)-glucans, which have been implicated in relation to fungal exposure-associated respiratory symptoms and as important stimulatory agents in anti-fungal immune responses. Fungi-and bacteria and plants-produce a wide variety of glucans with vast differences in the proportion and arrangement of their β-(1→3)-, -(1→4)- and -(1→6)-glycosidic linkages. Thus far, the pro-inflammatory potential of different β-glucans has not been studied within the same experimental model. Therefore, we compared the potency of 13 different glucan preparations to induce in vitro production of IL-1β, IL-6, IL-8 and TNF-α in human, whole blood cultures. The strongest inducers of all cytokines were pustulan [β-(1→6)-glucan], lichenan [β-(1→3)-(1→4)-glucan], xyloglucan [β-(1→4)-glucan] and pullulan [α-(1→4)-(1→6)-glucan]. Moderate-to-strong cytokine production was observed for curdlan [β-(1→3)-glucan], baker's yeast glucan [β-(1→3)-(1→6)-glucan] and barley glucan [β-(1→3)-(1→4)-glucan], while all other glucan preparations induced very low, or no, detectable levels of cytokines. We therefore conclude that innate immunity reactions are not exclusively induced by β-(1→3)-glucans, but also by β-(1→6)- and β-(1→4)-structures. Thus, not only β-(1→3)-glucan, but also other β-glucans and particularly β-(1→6)-glucans should be considered in future research.

Soluble glucomannan isolated from Candida utilis primes blood phagocytes

It is well documented that the polysaccharide glucomannan (GM), an abundant constituent of the fungal cell wall, in the form of particulate induces strong activation of phagocytes, however, the effects of soluble GM are not known. Activation of phagocyte anti-microbial mechanisms is a crucial part of the innate host defense against invading pathogens. However, under uncontrolled inflammatory conditions they contribute to damage of surrounding tissues. Thus, to prevent these deleterious effects, the activation of phagocytes is a tightly regulated process. Therefore, in this study we analyzed the effect of soluble GM on some neutrophil functions such as reactive oxygen species production, degranulation, and receptor mobilization at the plasma membrane. Soluble GM at the tested concentrations did not stimulate oxidative burst of phagocytes directly but significantly potentiated oxidative burst in response to opsonized zymosan particles. GM induced significant phosphorylation of p47phox subunit of NADPH oxidase on Ser345. This priming effect of GM was accompanied by time and concentration dependent degranulation characterized by increased surface expression of receptors stored in neutrophil granules (CD10, CD11b, CD14, CD35, and CD66b). Degranulation was further confirmed by increase of elastase activity in media. Thus, it could be suggested that soluble GM induces priming of phagocytes connected with their degranulation, the increase of surface receptor expression, and potentiation of oxidative burst response to opsonized particles through the activation of NADPH oxidase.

Photoprotective effects of glucomannan isolated from Candida utilis

Glucomannans belong to yeast and fungal cell wall polysaccharides with known immunostimulatory and radioprotective effects. However, glucomannan protective effects against pathological consequences of skin exposure to short wavelength solar light, ultraviolet (UV) radiation, are unclear. Herein, a highly branched glucomannan (GM) isolated from the cell wall of Candida utilis, a member of the alpha-(1-->6)-D-mannan group, was tested for its photoprotective effects in an in vitro model of UVB-irradiated human keratinocytes and an in vivo model of UV-induced erythema formation in human volunteers. GM suppressed the UVB-induced decrease of keratinocyte viability, which was connected with the suppression of UVB-induced keratinocyte apoptosis. GM reduced UVB-mediated caspase activation together with suppression of DNA fragment release into the cytoplasm. Furthermore, GM suppressed UVB-induced gene expression of pro-inflammatory markers including nuclear factor kappa B, inducible nitric oxide synthase, interleukins 8 and 1, together with suppression of prostaglandin E2 and interleukin 1alpha protein release. In vivo, GM decreased UV-induced skin erythema formation, which was correlated with a decrease of phosholipase A(2) activity within the stratum corneum. It could be concluded that GM isolated from C. utilis possesses significant photoprotective effects on human keratinocytes in vitro as well as in vivo.

Potentiation of histamine release by Microfungal (1-->3)- and (1-->6)-beta-D-glucans

(1-->3)-beta-D-Glucans, a cell wall component in most microfungi, are suggested to play a role in the development of respiratory and general symptoms in organic dust-related diseases. The mechanisms by which they induce these effects are, however, not clear. In the present study, mediator release and its potentiation by the (1-->3)-beta-D-glucan as well as by the (1-->6)-beta-D-glucan found in yeast and other fungi were therefore examined. Blood leucocytes from healthy volunteers and from patients allergic to house dust mite were incubated with (1-->3)-beta-D-glucans with increasing 1,6-branchings: curdlan [a linear (1-->3)-beta-D-glucan], laminarin and scleroglucan, and furthermore with pustulan, a linear (1-->6)-beta-D-glucan. Histamine release was not observed on exposure to the glucans only, but in the presence of anti-immunoglobulin E (IgE) antibody or specific antigens, all the glucans investigated led to an enhancement of the IgE-mediated histamine release. The glucans induced a significant potentiation of the mediator release when present at concentrations in the range of 2-5 x 10(-5) M. These results suggest that (1-->3)-beta-D-glucan as well as (1-->6)-beta-D-glucan aggravates IgE-mediated histamine release. Knowledge concerning the effects of glucans on immune responses may be of importance for understanding and treating inflammatory and allergic diseases.

beta-Glucans in promoting health: prevention against mutation and cancer

The polysaccharides beta-glucans occur as a principal component of the cellular walls. Some microorganisms, such as yeast and mushrooms, and also cereals such as oats and barley, are of economic interest because they contain large amounts of beta-glucans. These substances stimulate the immune system, modulating humoral and cellular immunity, and thereby have beneficial effect in fighting infections (bacterial, viral, fungal and parasitic). beta-Glucans also exhibit hypocholesterolemic and anticoagulant properties. Recently, they have been demonstrated to be anti-cytotoxic, antimutagenic and anti-tumorogenic, making them promising candidate as pharmacological promoters of health.

Natural and modified (1-->3)-beta-D-glucans in health promotion and disease alleviation

A number of polysaccharides with beta-glycosidic linkage are widespread in nature in a variety of sources. All have a common structure and the (1-->3)-beta-D-glucan backbone is essential. They have attracted attention over the years because of their bioactive and medicinal properties. In many cases their functional role is a mystery, in others it is well established. Because of their insoluble chemical nature, particulate (1-->3)-beta-D-glucans are not suitable for many medical applications. Various methods of changing or modifying the beta-D-glucan chemical structure and transforming it to a soluble form have been published. The beta-D-glucan bioactive properties can be affected positively or negatively by such modifications. This review examines beta-glucan sources in nature, health effects and structure-activity relationships. It presents the current state of beta-D-glucan solubilization methods and discusses their effectiveness and application possibilities for the future.