[Evaluation of the Acute Toxicity and Genotoxicity of the Rice Biofortified with ß-Glucan].

OBJECTIVE: To provide a scientific evaluation of the food safety of the rice biofortified with ß-glucan. METHODS: The acute toxicity and genotoxicity of the rice were evaluated by 14-day feeding experiment, Ames experiment, erythrocyte micronucleus test and mouse lymphoma thymidine kinase gene ( TK) mutation assay respectively. RESULTS: In the acute toxicity test, there was no obvious toxicity of rice biofortified with ß-glucan, and no abnormality was found in anatomical observation. The median lethal dose (LD 50) to rats and mice wereall greater than 15 mg/kg, which belonged to the actual non-toxic level. Whether with S 9 activation or not, no genotoxicity was found to the tested strains TA97a, TA98, TA100, TA102 and TA1535. No induction of polychromatic erythrocytes and inhibition of bone marrow were found in erythrocyte micronucleus test. The results of TK gene mutation assay did not show the mutagenicity of ß-glucan bioaugmentation rice. All results of the three genotoxicity tests were negative. CONCLUSION: Under the current experimental conditions, ß-glucan biofortified rice showed no obvious acute toxicity and genotoxicity.

Subchronic toxicity and genotoxicity studies of Antrodia mushroom ß-glucan preparation.

Antrodia cinnamomea is one of the most highly valued mushrooms utilized in traditional Taiwanese therapeutic practices. Its neutral monosaccharides (mannose, glucose and xylose) linked by a ß-D-glucan chain have been claimed to be responsible for its health benefits. The objective of the present study was to investigate adverse effects, if any, of ß-glucan (∼65% pure) from A. cinnamomea in subchronic toxicity and mutagenicity studies. In the subchronic toxicity study, Sprague Dawley rats (12/sex/group) were followed Organization for Economic Cooperation and Development (OECD) test guideline with Good Laboratory Practice (GLP) application, and were administered (gavage) Antrodia mushroom ß-glucan preparation at dose levels of 0, 500, 1000 and 2000 mg/kg body weight (bw)/day for 90 days. Treatment with ß-glucan preparation did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. The clinical pathology as studied by hematology, serum chemistry, urinalysis or terminal necropsy (gross or histopathology findings) did not reveal any treatment-related adverse effects. The results of mutagenicity studies as evaluated by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test in mice did not reveal any genotoxicity of ß-glucan preparation. Based on the subchronic study, the no observed-adverse-effect level (NOAEL) for ß-glucan preparation from Antrodia mushroom was determined as 2000 mg/kg bw/day, the highest dose tested.

ß-Glucan exacerbates allergic airway responses to house dust mite allergen.

ß-(1,3)-Glucan is present in mould cell walls and frequently detected in house dust mite (HDM) faeces. ß-Glucan exposure is thought to be associated with pulmonary allergic inflammation in mouse and man, although the published data are inconsistent. Here, we show that highly purified ß-glucan exacerbates HDM-induced eosinophilic, T helper 2 type airway responses by acting as an adjuvant, promoting activation, proliferation and polarisation of HDM-specific T cells (1-Derß T cells). We therefore provide definitive evidence that ß-glucan can influence allergic pulmonary inflammation.

Evidence for Proinflammatory ß-1,6 Glucans in the Pneumocystis carinii Cell Wall.

Inflammation is a major cause of respiratory impairment during Pneumocystis pneumonia. Studies support a significant role for cell wall ß-glucans in stimulating inflammatory responses. Fungal ß-glucans are comprised of d-glucose homopolymers containing ß-1,3-linked glucose backbones with ß-1,6-linked glucose side chains. Prior studies in Pneumocystis carinii have characterized ß-1,3 glucan components of the organism. However, recent investigations in other organisms support important roles for ß-1,6 glucans, predominantly in mediating host cellular activation. Accordingly, we sought to characterize ß-1,6 glucans in the cell wall of Pneumocystis and to establish their activity in lung cell inflammation. Immune staining revealed specific ß-1,6 localization in P. carinii cyst walls. Homology-based cloning facilitated characterization of a functional P. carinii kre6 (Pckre6) ß-1,6 glucan synthase in Pneumocystis that, when expressed in kre6-deficient Saccharomyces cerevisiae, restored cell wall stability. Recently synthesized ß-1,6 glucan synthase inhibitors decreased the ability of isolated P. carinii preparations to generate ß-1,6 carbohydrate. In addition, isolated ß-1,6 glucan fractions from Pneumocystis elicited vigorous tumor necrosis factor alpha (TNF-α) responses from macrophages. These inflammatory responses were significantly dampened by inhibition of host cell plasma membrane microdomain function. Together, these studies indicate that ß-1,6 glucans are present in the P. carinii cell wall and contribute to lung cell inflammatory activation during infection.

Acceleration of SLE-like syndrome development in NZBxNZW F1 mice by beta-glucan.

Beta-glucans are naturally occurring polysaccharides that exert important immunostimulatory activities. In the present study, we evaluated whether beta-glucans could modulate the development and the course of systemic lupus erythematosus (SLE). To this aim, we employed the classical model of SLE represented by the F1 hybrid between the NZB and NZW mouse strains which develop severe lupus-like phenotypes comparable to that of SLE patients. The administration of beta-glucan was associated to a more aggressive development of the disease and a worse prognosis, as observed from the clinical, biochemical and histopathological data. This finding implies that restraint should be practised in the possible use of beta-glucans as immunomodulators in human therapy in the context of SLE.

Early life microbial exposure and fractional exhaled nitric oxide in school-age children: a prospective birth cohort study.

BACKGROUND: Inflammation is a key factor in the pathogenesis of respiratory diseases. Early life exposure to microbial agents may have an effect on the development of the immune system and on respiratory health later in life.In the present work we aimed to evaluate the associations between early life microbial exposures, and fractional exhaled nitric oxide (FeNO) at school age. METHODS: Endotoxin, extracellular polysaccharides (EPS) and ß(1,3)-D-glucan were measured in living room dust collected at 2-3 months of age in homes of participants of three prospective European birth cohorts (LISA, n = 182; PIAMA, n = 244; and INMA, n = 355). Home dampness and pet ownership were periodically reported by the parents through questionnaires. FeNO was measured at age 8 for PIAMA and at age 10/11 for LISA and INMA. Cohort-specific associations between the indoor microbial exposures and FeNO were evaluated using multivariable regression analyses. Estimates were combined using random-effects meta-analyses. RESULTS: FeNO at school age was lower in children exposed to endotoxin at age 2-3 months (ß -0.05, 95% confidence interval (CI) -0.10;-0.01) and in children with reported dog ownership during the first two years of life (GM ratio 0.82, CI 0.70-0.96). FeNO was not significantly associated with early life exposure to EPS, ß(1,3)-D-glucan, indoor dampness and cat ownership. CONCLUSION: Early life exposure to bacterial endotoxin and early life dog ownership are associated with lower FeNO at school age. Further studies are needed to confirm our results and to unravel the underlying mechanisms and possible clinical relevance of this finding.

Induction of Dectin-1 and asthma-associated signal transduction pathways in RAW 264.7 cells by a triple-helical (1, 3)-ß-D glucan, curdlan.

People living in damp buildings are typically exposed to spore and mycelial fragments of the fungi that grow on damp building materials. There is experimental evidence that this exposure to triple-helical (1, 3)-ß-D glucan and low molecular weight toxins may be associated with non-atopic asthma observed in damp and moldy buildings. However, the mechanisms underlying this response are only partially resolved. Using the pure (1, 3)-ß-D glucan, curdlan, and the murine macrophage cell line, RAW 264.7, there were two objectives of this study. The first was to determine whether signal transduction pathways activating asthma-associated cell signaling pathways were stimulated using mouse transduction Pathway Finder(®) arrays and quantitative real-time (QRT) PCR. The second objective was to evaluate the dose and temporal responses associated with transcriptional changes in asthma-associated cytokines, the signal transduction receptor gene Dectin-1, and various transcription factor genes related to the induction of asthma using customized RT-PCR-based arrays. Compared to controls, the 10(-7) M curdlan treatment induced significant changes in gene transcription predominately in the NFkB, TGF-ß, p53, JAK/STAT, P13/AKT, phospholipase C, and stress signaling pathways. The 10(-8) M curdlan treatment mainly induced NFkB and TGF-ß pathways. Compared to controls, curdlan exposures also induced significant dose- and time-dependent changes in the gene translations. We found that that curdlan as a non-allergenic potentiator modulates a network of transduction signaling pathways not only associated with TH-1, TH-2, and TH-3 cell responses including asthma potentiation, but a variety of other cell responses in RAW 264.7 cells. These results help provide mechanistic basis for some of the phenotypic changes associated with asthma that have been observed in in vitro, in vivo, and human studies and open up a hypothesis-building process that could explain the rise of non-atopic asthma associated with fungi.

Single oral dose toxicity test of polycalcium, a mixed composition of polycan and calcium lactate-gluconate 1:9 (G/G) in SD rat.

The object of this study was to obtain acute oral toxicity information of Polycalcium, a mixed composition of Polycan and Calcium lactate-gluconate 1:9 (g/g), in Sprague-Dawely (SD) rats. In order to investigate the toxicity and identify target organs, Polycalcium were once orally administered to female and male SD rats at dose levels of 2000, 1000, 500 and 0 (control) mg/kg body weights. The mortality, changes on body weight and clinical signs were monitored during 14 days after treatment with gross observation, changes on the organ weights and histopathology of principle organs and treatment sites based on the recommendation of KFDA Guidelines [2009-116, 2009]. As the results of single oral treatment of Polycalcium, no treatment related mortalities were observed within 14 days after end of treatment up to 2000 mg/kg, the limited dosage of rodents in the both genders. In addition, no Polycalcium treatment related changes on the body and organ weights, clinical signs, necropsy and histopathological findings were detected. The results obtained in this study suggest that the Polycalcium is non-toxic in rats. The LD50 and approximate LD in rats after single oral dose of Polycalcium were considered over 2000 mg/kg in both female and male, respectively.

Toxicological assessment of ß-(1-->6)-glucan (lasiodiplodan) in mice during a 28-day feeding study by gavage.

Studies evaluating the toxicity caused by fungal exopolysaccharides of the ß-(1-->6)-D-glucan type are rare. In this study, the toxicological effects of sub-chronic treatments with lasiodiplodan (ß-(1-->6)-D-glucan from Lasiodiplodia theobromae MMPI) were evaluated in mice through the assessment of biochemical, hematological, and histopathological alterations. Thirty-two mice (16 male, 16 female) were used in this study divided in two groups; one group received lasiodiplodan (50 mg/kg body weight) daily for 28 days via gavage, and another (control group) received saline during the same period. Blood samples were collected via cardiac puncture for hematological and biochemical analyses. Liver, heart, kidney, and spleen were collected for histopathological analysis. Statistical analysis was performed through one-way analysis of variance and only p < 0.05 F-values were presented. Significant reduction in blood glucose in the male group (35%; p < 0.01), transaminases activity in both sexes (AST and ALT; ~35%; p < 0.05), and urea (20%; p < 0.01) in the female group was observed with the lasiodiplodan treatment. The results showed that sub-chronic treatments with lasiodiplodan did not generate hematological and histopathological alterations leading to signs of toxicity in healthy mice, independent of gender.

Efficiency of mesoporous silica/carboxymethyl ß-glucan as a fungicide nano-delivery system for improving chlorothalonil bioactivity and reduce biotoxicity.

Understanding the lethal effects of pesticides nano formulations on the targeted organisms (pathogens) and the non-targeted organisms (fish, earthworms, etc) is essential in assessing the probable impact of new technologies on agriculture and environment. Here we evaluated the bioactivity and the biotoxicity of new type of fungicide smart-delivery formulation based on conjugating carboxymethylated-ß-glucans on the mesoporous silica nanoparticles (MSNs) surface after loading chlorothalonil (CHT) fungicide in the MSNs pores. The obtained formulation has been characterized with FE-SEM, and HR-TEM. The CHT loading efficiency has been measured with TGA. The bioactivity of the obtained formulation (CHT@MSNs-ß-glucans) has been tested against four pathogens, fusarium head blight (Fusarium graminearum), sheath rot (Sarocladium oryzae), rice sheath blight (Rhizoctonia solani), and soyabean anthracnose (Colletotrichum truncatum) compared with CHT WP 75% commercial formulation (CHT-WP) and technical CHT. The environmental biotoxicity of CHT@MSNs-ß-glucans compared with CHT-WP has been tested toward earthworm (Eisenia fetida) and zebra fish (Danio rerio). The results showed that CHT@MSNs-ß-glucans has an excellent bioactivity against the subjected pathogens with better inhabiting effects than CHT-WP. CHT@MSNs-ß-glucans toxicity to Eisenia fetida was found 2.25 times lower than CHT-WP toxicity. The LC50 of CHT@MSNs-ß-glucans to zebra fish after the first 24h was 2.93 times higher than CHT-WP. After 96h of treatment, the LC50 of CHT@MSNs-ß-glucans was 2.66 times higher than CHT-WP. This work highlighted the necessity to increase the mandatory bioassays of nano formulations with the major non-target organisms in the environmental risk assessment of new pesticide formulations.

Depletion of CD4+CD25+Foxp3+ regulatory T cells with anti-CD25 antibody may exacerbate the 1,3-ß-glucan-induced lung inflammatory response in mice.

1,3-ß-Glucan was a major cell wall component of fungus. The existing studies showed that 1,3-ß-glucan exposure could induce lung inflammation that involved both Th1 and Th2 cytokines. Regulatory T cells (Treg cells) played a critical role in regulating immune homeostasis by adjusting the Th1/Th2 balance. The role of Treg cells and regulatory mechanism in 1,3-ß-glucan-induced lung inflammation is still unclear. In our study, mice were exposed to 1,3-ß-glucan by intratracheal instillation. To investigate the role of Treg cells in response to 1,3-ß-glucan, we generated Treg-depleted mice by intraperitoneal administration of anti-CD25 mAb. The Treg-depleted mice showed more inflammatory cells and severer pathological inflammatory change in lung tissue. Depletion of Treg cells led to increased Th1 cytokines and decreased Th2 cytokines. Treg-depleted mice showed a decreased expression of anti-inflammation cytokine and lower-level expression of CTLA-4. In all, our study indicated that Treg cells participated in regulating the 1,3-ß-glucan-induced lung inflammation. Depletion of Treg cells aggravated the 1,3-ß-glucan-induced lung inflammation, regulated the Th1/Th2 balance by enhancing Th1 response. Treg cells exerted their modulation function depending on both direct and indirect mechanism during the 1,3-ß-glucan-induced lung inflammation.

Acute and subchronic toxicity of FCD, a soybean extract combined with L-carnitine, in Sprague-Dawley rats.

Soy products are primarily composed of proteins, phytochemicals such as isoflavones, soy lipids, and carbohydrates. Recently, soy isoflavones with L-carnitine were reported to exhibit anti-obesity effects in mice. FCD, a combination of soybean extract and L-carnitine, is a newly developed food substance. As a part of its safety assessment, acute and 13-week subchronic toxicity studies were performed in a total of 100 Sprague-Dawley (SD) rats. In the acute study, a single limit dose of 2000 mg/kg was orally administered to five male and five female rats. No adverse effects or mortality was observed during a 14-day period or upon gross pathological examination. In the subchronic study, FCD was orally administered in daily doses of 500, 1000, and 2000 mg/kg for 13 weeks, resulting in no mortality, and no changes in hematological and serum biochemistry parameters, gross pathology or histopathology. However, body weights of females were significantly decreased 10 weeks after treatment at an average of 2000 mg/kg. In addition, a slight decrease in mean food and water consumption was observed at the same dose level for 13 weeks. Therefore, the no-observed-adverse-effect-level (NOAEL) of FCD was considered to be 2000 mg/kg for male and 1000 mg/kg for female SD rats.

Induction of GSNO reductase but not NOS in the lungs of mice exposed to glucan-spiked dust.

Both in vivo and in vitro studies have suggested that airborne organic dusts may induce inflammatory responses in the lungs, characterized by typical patterns of cytokine up-regulation and secretion. Recent work showed that exposure to glucan-spiked dust might influence nasal and pulmonary function, without an accompanying inflammatory response. However, effects of glucan-spiked dust exposure on NOS and GSNO reductase (enzymes important to NO signaling) remain less clear. This study aims to determine the effects of simultaneous exposure to glucan-spiked dust on NO signaling pathway in the airway. Danish Office dust was spiked with 1% (1-3)-ß-glucan (curdlan). Mice were exposed to 20 µL PBS (controls), 20 µL 25 µg/20 µL OVA and 20 µL 100 µg/20 µL glucan-spiked dust, respectively, daily for 12 days. NOS and GSNO reductase activity were measured in lung homogenate. Glutathione concentration and SOD activity in lung tissue were also determined to evaluate changes in oxidative stress. IL-6 concentration was measured in lungs to quantify the inflammatory response. Results showed that 12 day OVA and glucan-spiked dust exposure did not significantly influence NOS activity, GSH concentration, SOD activity, or IL-6 concentration. An insignificant increase in GSNOR activity and expression was observed in 12 day OVA-exposed mice, whereas glucan-spiked dust exposure significantly increased GSNOR activity and expression. Our results suggested that repeated glucan-spiked dust exposure to the airway could activate GSNO reductase but not NOS. Since GSNO reductase plays a pivotal role in NO signaling, these results may have clinical importance.

Comparison of workplace protection factors for different biological contaminants.

This study compared workplace protection factors (WPFs) for five different contaminants (endotoxin, fungal spores, (1→3)-ß-D-glucan, total particle mass, and total particle number) provided by an N95 elastomeric respirator (ER) and an N95 filtering facepiece respirator (FFR). We previously reported size-selective WPFs for total particle numbers for the ER and FFR, whereas the current article is focused on WPFs for bioaerosols and total particle mass. Farm workers (n = 25) wore the ER and FFR while performing activities at eight locations representing horse farms, pig barns, and grain handling facilities. For the determination of WPFs, particles were collected on filters simultaneously inside and outside the respirator during the first and last 15 min of a 60-min experiment. One field blank per subject was collected without actual sampling. A reporting limit (RL) was established for each contaminant based on geometric means (GMs) of the field blanks as the lowest possible measurable values. Depending on the contaminant type, 38-48% of data points were below the RL. Therefore, a censored regression model was used to estimate WPFs (WPF(censored)). The WPF(censored) provided by the two types of respirators were not significantly different. In contrast, significant differences were found in the WPF(censored) for different types of contaminants. GMs WPFs(censored) for the two types of respirators combined were 154, 29, 18, 19, and 176 for endotoxin, fungal spore count, (1→3)-ß-D-glucan, total particle mass, and total particle number, respectively. The WPF(censored) was more strongly associated with concentrations measured outside the respirator for endotoxin, fungal spores, and total particle mass except for total particle number. However, when only data points with outside concentrations higher than 176×RL were included, the WPFs increased, and the association between the outside concentrations and the WPFs became weaker. Results indicate that difference in WPFs observed between different contaminants may be attributed to differences in the sensitivity of analytical methods to detect low inside concentrations, rather than the nature of particles (biological or non-biological).

Assessment of toxicological potential of sodium carboxymethyl beta-glucan, a novel beta-glucan.

In this experimental work, sodium carboxymethyl beta-glucan (CMBG), a chemically altered beta-glucan, is evaluated for mutagenicity and sub-acute oral toxicity. Specifically, the tested material was CM-Glucan Nu, a food grade powder ≥90% CMBG derived from Saccharomyces cerevisiae. A bacterial reverse mutation test was performed and resulted in no mutagenicity. A 28-day, repeated-dose, oral (gavage) toxicity test on rats was performed at dose levels of 0, 500, 1000, and 2000 mg/kg bw/day. No mortality, target organs or other treatment related effects were observed. The no observed adverse effect level (NOAEL) was 2000 mg/kg bw/day, the highest dose tested, for both male and female Han:WIST rats.

Antifracture, Antibacterial, and Anti-inflammatory Hydrogels Consisting of Silver-Embedded Curdlan Nanofibrils.

The bacterial exopolysaccharide Curdlan has a unique collagen-like triple helical structure and immune-modulation activities. Although there have been several types of Curdlan gels reported for antibacterial or wound healing purposes, none of them exhibit favorable mechanical properties for clinically applicable wound healing materials. Herein, we present a two-step approach for preparing Ag-embedded Curdlan hydrogels that are highly soft but are very stretchable compared with common polysaccharide-based hydrogels. Ag ions were first reduced in a diluted Curdlan solution to form AgNP-decorated triple helices. Then, the aqueous solution consisting of Curdlan/Ag nanoparticles was mixed with a dimethyl sulfoxide solution consisting of a high concentration of Curdlan. This mixing triggered the conformation transformation of Curdlan random coils into triple helices, and then the helices were further packed into semicrystalline nanofibrils of ∼20 nm in diameter. Due to the presence of semicrystalline fibrils, this novel Curdlan hydrogel exhibits a fracture strain of ∼350% and fracture stress of ∼0.2 MPa at a water content of ∼97%. This nanofibril hydrogel supported the attachment, spreading, and growth of fibroblasts and effectively inhibited the growth of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Moreover, the hydrogels downregulated NO production and proinflammatory gene expression levels in lipopolysaccharide (LPS)-stimulated macrophages but did not change the anti-inflammatory gene expression levels in IL-4-stimulated macrophages. In an animal study, these hydrogels accelerated wound healing in a bacteria-infected mice skin wound model. These results validate the further development of Curdlan/AgNPs nanofibril hydrogels in clinical wound management.

Yeast Shells Encapsulating Adjuvant AS04 as an Antigen Delivery System for a Novel Vaccine against Toxoplasma Gondii.

Toxoplasma gondii (T. gondii) infection causes severe zoonotic toxoplasmosis, which threatens the safety of almost one-third of the human population globally. However, there is no effective protective vaccine against human toxoplasmosis. This necessitates anti-T. gondii vaccine development, which is a main priority of public health. In this study, we optimized the adjuvant system 04 (AS04), a vaccine adjuvant constituted by 3-O-desacyl-4'-monophosphoryl lipid A (a TLR4 agonist) and aluminum salts, by packing it within natural extracts of ß-glucan particles (GPs) from Saccharomyces cerevisiae to form a GP-AS04 hybrid adjuvant system. Through a simple mixing procedure, we loaded GP-AS04 particles with the total extract (TE) of T. gondii lysate, forming a novel anti-T. gondii vaccine GP-AS04-TE. Results indicated that the hybrid adjuvant can efficiently and stably load antigens, mediate antigen delivery, facilitate the dendritic uptake of antigens, boost dendritic cell maturation and stimulation, and increase the secretion of pro-inflammatory cytokines. In the mouse inoculation model, GP-AS04-TE significantly stimulated the function of dendritic cells, induced a very strong TE-specific humoral and cellular immune response, and finally showed a strong and effective protection against toxoplasma chronic and acute infections. This work proves the potential of GP-AS04 for exploitation as a vaccine against a range of pathogens.

Dectin-1 and inflammation-associated gene transcription and expression in mouse lungs by a toxic (1,3)-beta-D glucan.

The form of (1-3)-beta-D glucan found in the cell walls of the anamorphic Trichocomaceae that grow on damp building materials is considered to have potent toxic and inflammatory effects on cells of the respiratory system. It is also considered to have a potential role in the development of non-allergenic respiratory health effects. While human studies involving experimental exposures all point to the inflammatory potential of pure curdlan, a linear (1-3)-beta-D glucan in a triple helix configuration, animal experiments result in conflicting conclusions concerning the inflammatory potency of this glucan. However, because mice appear to be a better model than guinea pigs for exploring the respiratory effects of curdlan and because molecular mechanisms associated with this glucan remain largely unknown, we conducted further work to clarify the role of curdlan on the inflammatory response using our mouse model of lung disease. This study used in situ hybridization (ISH) to probe dectin-1 mRNA transcription with a digoxigenin-labeled cDNA probe, with reverse transcription (RT)-PCR based arrays used to measure inflammation gene and receptor transcriptional responses. Also, immunohistochemistry (IHC) was used to probe dectin-1 as well as anti-mouse Ccl3, Il1-alpha, and TNF-alpha expression to evaluate dose and time-course (4 and 12 h) postexposure (PE) response patterns in the lungs of intratracheally instilled mice exposed to a single 50 mul dose of curdlan at 10(-7), 10(-8), 10(-9), and 10(-10) M/animal (=4 mug to 4 ng curdlan/kg lung wt). Dectin-1 mRNA transcription and expression was observed in bronchiolar epithelium, alveolar macrophages (AMs), and alveolar type II cells (ATIIs) of lungs exposed to 4 mug to 40 ng curdlan/kg lung wt, at both time points. Compared to controls, array analysis revealed that 54 of 83 genes assayed were significantly modulated by curdlan. mRNA transcription patterns showed both dose and time dependency, with highest transcription levels in 10(-7) and 10(-8) M treatment animals, especially at 4-h PE. Nine gene mRNA transcripts (Ccl3, Ccl11, Ccl17, Ifng, Il1alpha, Il-20, TNF-alpha, Tnfrsf1b, and CD40lg) were significantly expressed at all doses suggesting they may have a central role in immunomodulating curdlan exposures. IHC revealed Ccl3, Il1-alpha, and TNF-alpha expression in bronchiolar epithelium, AMs and ATIIs illustrate the important immunomodulatory role that these cells have in the recognition of, and response to glucan. Collectively, these results confirm the inflammatory nature of curdlan and demonstrate the complex of inflammation-associated gene responses induced by (1-3)-beta-D glucan in triple helical forms. These observations also provide a biological basis for the irritant and inflammatory response to curdlan observed in humans and animals in experimental studies.

Study on chemopreventive effects of raw and roasted ß-glucan-rich waxy winter barley using an in vitro human colon digestion model.

Due to their unique dietary fibre composition, in particular ß-glucan, the consumption of barley may contribute to a healthy diet and the prevention of colon cancer. The aim of the present study was to analyse chemopreventive effects of barley flakes obtained from a ß-glucan-rich barley cultivar. In order to address the impact of heat treatment on potential chemopreventive effects, barley flakes were roasted (160 °C-180 °C, approx. 20 min). The flakes were subjected to in vitro digestion and fermentation. Fermentation supernatants (FS) were analysed for the concentrations of short-chain fatty acids (SCFA) and ammonia. Chemopreventive endpoints (growth inhibition, apoptosis, DNA integrity, gene expression of detoxifying enzymes) were analysed in LT97 colon adenoma cells. Concentrations of SCFA were increased in barley FS (2.5-fold, on average) with a shift of molar ratios towards butyrate production, while ammonia levels were significantly decreased (0.7-fold, on average) compared to the fermentation control. The growth of LT97 cells was significantly reduced by barley FS in a time- and dose-dependent manner, and caspase-3 activity of treated cells was significantly enhanced (up to 6.3-fold, on average). On average, treatment of cells resulted in increased mRNA levels of CAT (2.1-fold), SOD2 (2.2-fold) and GSTP1 (3.9-fold), while expression of GPx1 (0.3-fold) was significantly decreased in some cases. The roasting process did not cause genotoxic effects of barley FS and had no impact on chemopreventive properties. Our results indicate chemopreventive potential of in vitro fermented waxy winter barley, mediated primarily by growth inhibitory and apoptotic effects, which is largely unaffected by roasting.

Pulmonary exposure to soluble cell wall beta-(1, 3)-glucan of aspergillus induces proinflammatory response in mice.

Compared to the significant immunomodulation of cell wall component(s) of bacterium such as lipopolysaccharide (E. Coli), that of pathogenic fungi has not been well elucidated, especially in vivo. Furthermore, although it has been implied that beta-(1, 3)-glucan of fungi possesses various biological activities, the impacts of the component have not been properly clarified, possibly due to its insolubility in water and alkali solutions. Previously, we isolated a soluble type of beta-(1, 3) -glucan from Aspergillus (referred to as ASBG). The present study investigated the effects of a single pulmonary exposure to ASBG on the immune (proinflammatory) responses in naïve mice. ASBG (12.5-100micorg/animal) exposure Induced neutrophilic lung inflammation with an enhanced local expression of proinflammatory cytokines such as interleukin (IL)-1beta and chemokines such as macrophage inflammatory protein -1a, and keratinocyte-derived chemoattractant in a dose-dependent fashion with overall trends. On the other hand, ASBG at relatively lower doses significantly amplified the lung expression of IL-2, IL-6, and IL-12 as compared with vehicle. ASBG significantly induced pulmonary edema. Furthermore, ASBG augmented the nuclear translocation of nuclear factor (NF)-kB and its binding capacity to the promoter site of DNA in the lung homogenate. These results suggest that pulmonary exposure to ASBG confers lung inflammation, at least partly, via the enhanced local expression of proinflammatory cytokines, likely through NF-kB-dependent pathway.