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Nanoparticles (NPs) that can activate macrophages infected with the tuberculosis causative pathogen Mycobacterium tuberculosis, could be an effective host directed therapy for the disease. In this study, curdlan was conjugated to poly(lactic-co-glycolic acid) (PLGA) to produce immunotherapeutic NPs. Various physicochemical characterizations were used to evaluate the curdlan-PLGA copolymer and the NPs. Molecular dynamics and simulation studies were used to characterize the interaction between curdlan, on the polymer and on NPs, with the Dectin-1 macrophage receptor. NPs with varying curdlan densities were evaluated for their effects on the production of pro- and anti-inflammatory cytokines in M. tuberculosis infected RAW264.7 macrophages. The killing efficacy of the NPs against intracellular M. tuberculosis was assessed. Physicochemical characterization of the curdlan-PLGA copolymer and NPs indicated successful formation of curdlan-PLGA copolymer and NPs of varying curdlan density (0 - 8% w/w) had sizes between 330 – 453 nm. Modelling studies showed curdlan to have a strong affinity for Dectin-1. Cytotoxicity assays showed the NPs to be non-toxic over 72 h. The proinflammatory cytokine TNF-α was found to be significantly upregulated by the NPs. The NPs reduced intracellular M. tuberculosis burden over 72 h. These NPs are a promising host directed therapy for intracellular eradication of M. tuberculosis.

β-glucan derived from the black yeast Aureobasidium pullulans (A. pullulans) is one of the natural products attracting attention due to its high potential for application as a functional food and pharmaceutical. Our team of researchers obtained a highly soluble, low-molecular-weight β-glucan from the fermentation culture medium of A. pullulans via mechanochemical ball milling method, that is, the low-molecular-weight A. pullulans-fermented β-D-glucan (LMW-AP-FBG). We investigated the anti-inflammatory effect of LMW-AP-FBG using lipopolysaccharide (LPS)-stimulated murine macrophages (RAW264.7 cells) in the current study. LMW-AP-FBG altered LPS-stimulated inflammatory responses by reducing the release of inflammatory mediators such as nitric oxide (NO), interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. As well, the mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) signaling pathways were downregulated by LMW-AP-FBG. Furthermore, LMW-AP-FBG markedly reduced LPS-induced expression of cell surface molecules, CD14, CD86, and MHC class II, which mediate macrophage activation. These findings suggest that LMW-AP-FBG can be used as an effective immune modulator to attenuate the progression of inflammatory disease.

β-glucan is an important functional active component with relatively high content in barley. It is reported to possess various biological activities, including anti-oxidative stress, but its mechanism of action remains obscure. In the current study, C. elegans was used as an in vivo animal model to explore its anti-oxidative stress mechanism. We found that both RBG (raw barley β-glucan) and FBG (fermented barley β-glucan) could significantly reduce the ROS level in C. elegans under oxidative emergency conditions. In addition, both FBG and RBG had positive effects on SOD and CAT enzyme activity, and FBG treatment obviously reduced the MDA content in nematodes under oxidative stress. Moreover, FBG and RBG pretreatment could extend the median lifespan of C. elegans under oxidative stress. The CB1370 and CF1038 mutants further confirmed that daf-2 and daf-16 were necessary for FBG or RBG to participate in anti-oxidative stress, and the RT-PCR results also evidenced that β-glucans resist oxidative stress in C. elegans partially through the daf-2/daf-16 pathway. In summary, barley β-glucan has high potential to defense oxidative stress as a natural polysaccharide.

To relieve the severe economic and social burdens and patient suffering caused by the increasing incidence of chronic wounds, more effective treatments are urgently needed. In this study, we focused on developing a novel sprayable wound dressing with the active ingredient β-1,3/1,6-glucan (βG). Since βG is already available as the active ingredient in a commercial wound healing product provided as a hydrogel in a tube (βG-Gel), the sprayable format should bring clinical benefit by being easily sprayed onto wounds; whilst retaining βG-Gel’s physical stability, biological safety and wound healing efficacy. Potentially sprayable βG hydrogels were therefore formulated, based on an experimental design setup. One spray formulation, named βG-Spray, was selected for further investigation, as it showed favorable rheological and spraying properties. The βG-Spray was furthermore found to be stable at room temperature for more than a year, retaining its rheological properties and sprayability. The cytotoxicity of βG-Spray in keratinocytes in vitro, was shown to be promising even at the highest tested concentration of 100 μg/ml. The βG-Spray also displayed favorable fluid affinity characteristics, with a capacity to both donate and absorb close to 10% fluid relative to its own weight. Finally, the βG-Spray was proven comparably effective to the commercial product, βG-Gel, and superior to both the water and the carrier controls (NoβG-Spray), in terms of its ability to promote wound healing in healing-impaired animals. Contraction was found to be the main wound closure mechanism responsible for the improvement seen in the βG-treatment groups (βG-Spray and βG-Gel). In conclusion, the novel sprayable βG formulation, confirmed its potential to expand the clinical use of βG as wound dressing.

The effect of dietary β-glucan on seminal plasma composition, sperm characteristics, expression of aquaporins, and antioxidative defence genes of golden mahseer was evaluated. For that, four experimental diets containing 0 (control), 0.5, 1, and 1.5% β-glucan were fed to male golden mahseer brooders for 130 days. Feeding of 0.5% β-glucan was found to improve sperm characteristics, viz. sperm count, motility, viability, and morphology with no effect on gonadosomatic index and seminal plasma energy resources. The marked down-regulation in the transcript abundance of testicular aqp3a noticed in 1.5% β-glucan fed brooders corresponds to their poor sperm quality. Further, the mRNA expression of genes encoding antioxidant enzymes, namely gst and sod1, was lowest in 0.5% β-glucan fed brooders. In contrast, control and higher β-glucan (1 and 1.5%) groups displayed relatively higher expression levels of testicular gst and sod1. On the other hand, the higher seminal plasma total antioxidant capacity observed in 0.5 and 1% β-glucan fed brooders indicated increased scavenging ability of reactive oxygen species. Overall, supplementation of 0.5% β-glucan improved sperm quality and antioxidative potential, but the higher inclusion (1.5%) negatively affected sperm characteristics. Collectively, dietary β-glucan (0.5%) can be a practical approach to developing quality broodstock of golden mahseer.

An eight-week feeding trial was performed to assess the effect of different dietary levels (0, 0.5, 1.0, and 1.5%) of β-glucan (sourced from Saccharomyces cerevisiae) on growth, survival, immunological parameters (immune gene expression, lysozyme, and antiprotease), total antioxidant status, thermal tolerance, and disease resistance of Tor putitora fry. Feeding of moderate doses (0.5 and 1.0%) of β-glucan significantly improved survival but not weight gain percentage as compared to that received unsupplemented control and highest dose (1.5%) of glucan. Supplementation of β-glucan in diets differentially influenced the mRNA expression of cytokine and other immune genes. For instance, transcripts of cytokines such as tnf-α and il-1β were significantly upregulated, while ifn-γ and il-10 were unaffected by β-glucan intake. Also, the relative mRNA expression of tlr-5 and hepcidin1 along with lysozyme and antiprotease activities were remained largely unchanged by dietary glucan administration. In contrast, β-glucan induced mRNA expression of defensin1 and c3 while decreased the transcript level of mhc-1. On the other hand, dietary inclusion of β-glucan markedly improved total antioxidant levels and extended the thermal tolerance limits at both the ends, as shown by increased CTmax and lower CTmin than the control group. After feeding β-glucan for eight weeks, the fish were bath challenged with a bacterial pathogen, Aeromonas salmonicida. The challenge study results revealed that β-glucan intake improved most of the studied immune parameters, resulting in lower mortality. Overall, dietary inclusion of β-glucan (0.5-1.0%) was efficient in improving the immune responses, thermal tolerance, and disease resistance of T. putitora fry.

Yeast glucan particles are porous polysaccharide cell walls extracted from Saccharomyces cerevisiae. Being mildly immunogenic, they are efficiently phagocytosed and have therefore been proposed as possible vehicles for drug delivery. Using curcumin as a model poorly water-soluble drug, a systematic comparison of three different physical loading methods – incipient wetness impregnation, slurry evaporation, and spray drying – was carried out and their influence on the particle morphology, encapsulation efficiency, amorphous drug content and release kinetics was evaluated. It was found that yeast glucan particles can contain up to 30% wt. of curcumin in the amorphous form when prepared by slurry evaporation. The dissolution of curcumin from glucan particles lead to a supersaturated solution in a similar way as amorphous solid dispersions do, despite the fact that glucan particles themselves do not dissolve. Bi-phasic dissolution tests revealed up to 4-fold acceleration of curcumin dissolution rate from amorphous glucan particles compared to its crystalline form. Crucially, glucan particles were shown to retain the ability to be recognised and phagocytosed even after drug encapsulation.

Introduction: As a supplement, beta-glucan has various therapeutic healing effects generated by the immune cells. It has been scientifically approved and proven to be a biological defense modifier. The aim of this study was to investigate the effects of beta-glucan on treatments administered in an acute otitis media model Objectives: This study investigated the effect of beta-glucan on the treatment of acute otitis media in an acute otitis media -induced animal model. Efficacy was evaluated both immunologically and histologically. Methods: The study sample comprised 35 adult rats, randomly separated into 5 groups of 7: Group 1 (control), Group 2 (acute otitis media, no treatment), Group 3 (acute otitis media + antibiotic), Group 4 (acute otitis media + beta-glucan) and Group 5 (acute otitis media + beta-glucan + antibiotic). Analyses were made of the histopathology and immunology examination results in respect of thickening of the tympanic membrane, epithelium damage, inflammation, and sclerosis. In all groups the serum levels of TNF-α, IL-4, IL-6 and IL-1β were evaluated. Results: All serum cytokine levels were significantly lower in the beta-glucan and antibiotictreated groups compared to the acute otitis media Group. Significant differences in tympanic membrane thickness, inflammation, epithelium damage, and sclerosis values were observed between the acute otitis media + antibiotic and acute otitis media + beta-glucan Groups. According to these parameters, the values in aute otitis media + antibiotic + beta-glucan Group were markedly lower than those of the other groups. There was a significant difference in the acute otitis media + antibiotic + beta-glucan Groups compared to acute otitis media Group (p < 0.001). Conclusions: Both antibiotic and beta-glucan treatment reduced acute otitis media signs of inflammations in an acute otitis media-induced rat model, decreasing histological damage and cytokine levels. Co-administration of antibiotic and beta-glucan led to a significant reduction in tympanic membrane thickness, inflammation, and epithelium damage. Antibiotic + beta-glucan treatment resulted in a greater decrease in tympanic membrane thickness, inflammation, and epithelium damage than in the other groups. From these results, it can be suggested that beta-glucan, in combination with antibiotics may provide an alternative for the treatment of acute otitis media. Resumo Introdução: Como suplemento, o beta-glucano apresenta vários efeitos terapêuticos gerados pelas células imunológicas. Cientificamente aprovado, mostrou ser um modificador de defesa biológica. Objetivo: Investigar os efeitos do beta-glucano nos tratamentos administrados em um modelo de otite média aguda induzida em um modeloanimal. A eficácia foi avaliada imunológica e histologicamente. Método: A amostra do estudo foi composta por 35 ratos adultos, divididos aleatoriamente em 5 grupos de 7: grupo 1 (controle), grupo 2 (otite média aguda, sem tratamento), grupo 3 (otite média aguda + antibiótico), grupo 4 (otite média aguda + beta-glucano) e grupo 5 (otite média aguda + beta-glucano + antibiótico). Foram feitas análises dos resultados dos exames histopatológicos e imunológicos em relação ao espessamento da membrana timpânica, dano ao epitélio, inflamação e esclerose. Os níveis séricos de TNF-α, IL-4, IL-6 e IL-β foram avaliados em todos os grupos. Resultados: Todos os níveis séricos de citocinas foram significativamente mais baixos nos grupos tratados com beta-glucano e antibióticos em comparação com o grupo otite média aguda. Diferenças significativas na espessura da membrana timpânica, inflamação, dano do epitélio e esclerose foram observadas entre os grupos otite média aguda + antibiótico e otite média aguda + beta-glucano. De acordo com esses parâmetros, os valores no grupo otite média aguda + antibiótico + beta-glucano foram acentuadamente inferiores aos dos demais grupos. Houve uma diferença significante no grupo otite média aguda + antibiótico + beta-glucano em comparação ao grupo otite média aguda (p < 0,001). Conclusão: Ambos os tratamentos com antibiótico e com beta-glucano reduziram os sinais de inflamação da otite média aguda em um modelo de rato com otite média aguda induzida, diminuíram os danos histológicos e os níveis de citocinas. A administração concomitante de antibiótico e beta-glucano levou a uma redução significativa na espessura da membrana timpânica, inflamação e danos ao epitélio. O tratamento com antibióticos + beta-glucano resultou em maior diminuição na espessura da membrana timpânica, inflamação e danos no epitélio do que nos outros grupos. A partir desses resultados, pode-se sugerir que o beta-glucano, em combinação com antibióticos, pode fornecer uma opção para o tratamento da otite média aguda.

The β-glucans are a disparate group of structurally diverse polysaccharides, whose members are widespread in human diets as components of the cell walls of plants, algae, and fungi (including yeasts), and as bacterial exopolysaccharides. Individual β-glucans from these sources have long been associated with positive effects on human health through metabolic and immunological effects. Remarkably, the β-configured glucosidic linkages that define these polysaccharides render them inaccessible to the limited repertoire of digestive enzymes encoded by the human genome. As a result, the various β-glucans become fodder for the human gut microbiota (HGM) in the lower gastrointestinal tract, where they influence community composition and metabolic output, including fermentation to short chain fatty acids (SCFAs). Only recently, however, have the specific molecular systems that enable the utilization of β-glucans by select members of the HGM been fully elucidated by combined genetic, biochemical, and structural biological approaches. In the context of β-glucan structures and their effects on human nutrition and health, we summarize here the functional characterization of individual polysaccharide utilization loci (PULs) responsible for the saccharification of mixed-linkage β(1→3)/β(1→4)-glucans, β(1→6)-glucans, β(1→3)-glucans, β(1→2)-glucans, and xyloglucans in symbiotic human gut bacteria. These exemplar PULs serve as well-defined biomarkers for the prediction of β-glucan metabolic capability in individual bacterial taxa and across the global human population.

Cationic polysaccharides have shown excellent ability of nucleic acids delivery. However, cationic curdlan derivatives with high degree of amination cause damage to the cell membrane and induce considerable cytotoxicity, limiting their in vivo application. Herein, we synthesized PEGylated 6-amino-6-deoxy-curdlan derivatives containing cleavable disulfide bonds. The resulting polymers (denote 6AC-2S PEGx) not only showed high affinity to siRNA but also exhibited significantly decreased cytotoxicity and hemolysis effect, while showing remarkable in vitro transfection efficiency. In vivo study demonstrated that 6AC-2S PEG40, which had a lower LD50 value than that of 6AC-100, did not cause liver damage, as the i.v. injection of 6AC-2S PEG40 to mouse did not increase serum level of ALT/AST. Furthermore, tissue distribution results showed that 6AC-2S PEG40 successfully delivered siRNA to liver, lung and spleen. Collectively, our data confirmed that PEGylation can increase the biocompatibility of cationic curdlan derivatives, which is a promising carrier for nucleic acid therapeutics.

application/pdf, Journal of Materials Chemistry B. 2021, 9 (37), P.7713-7724

The present study highlights/demonstrates facile synthesis of β-Glucan nanoparticles (β-GluNPs) that can be used in the prevention of breast cancer and other infectious diseases. Moreover, this method is inexpensive and shows effectivity towards different biological applications. Further, the characterization of synthesized β-GluNPs was exclusively confirmed through UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), high resolution-transmission electron microscopy (HR-TEM), and X-ray powder diffraction (XRD) analysis. The synthesized β-GluNPs were further confirmed by FT-IR spectroscopy. The HR-TEM results demonstrated that the formation of polydispersed nanoparticles with a mean size of 20 ± 5 nm. The hydrostatic zeta potential was − 22.7 mV, which indicated their colloidal stability. The XRD pattern revealed the crystalline nature of the nanoparticles. Besides, β-GluNPs showed better antibacterial activity against the tested pathogens. The apoptosis and DNA fragmentation observed to be IC50 42.5 µg/ml of the β-GluNPs. The DNA fragmentation assay indicated the selective inhibition of the MCF-7 cell line by DNA damage. Hence, the study reports that the β-GluNPs have a potential to be used as a promising alternative drug against human breast cancer.

Background High-molecular-weight (MW) oat β-glucan (OBG), consumed at 3-4 g/d, in solid foods reduces LDL cholesterol by a median of ∼6.5%. Objectives We evaluated the effect of a beverage providing 3 g/d high-MW OBG on reduction of LDL cholesterol (primary endpoint) when compared with placebo. Methods We performed a parallel-design, randomized clinical trial at a contract research organization; participants, caregivers, and outcome assessors were blinded to treatment allocation. Participants with LDL cholesterol between 3.0 and 5.0 mmol/L, inclusive [n = 538 screened, n = 260 ineligible, n = 23 lost, n = 48 withdrawn (product safety); n = 207 randomly assigned, n = 7 dropped out, n = 9 withdrawn (protocol violation); n = 191 analyzed; n = 72 (37.7%) male, mean ± SD age: 43.3 ± 14.3 y, BMI: 29.7 ± 5.2 kg/m2], were randomly assigned to consume, 3 times daily for 4 wk, 1 g OBG (n = 104, n = 96 analyzed) or rice powder (Control, n = 103, n = 95 analyzed) mixed into 250 mL water. Treatment effects were assessed as change from baseline and differences analyzed using a 2-sided t test via ANOVA with baseline characteristics as covariates. Results After 4 wk, change from baseline least-squares-mean LDL cholesterol on OBG (-0.195 mmol/L) was less than on Control (0.012 mmol/L) by mean: 0.207 mmol/L (95% CI: 0.318, 0.096 mmol/L; P = 0.0003); the following secondary endpoints were also reduced as follows: total cholesterol (TC) (0.226 mmol/L; 95% CI: 0.361, 0.091 mmol/L; P = 0.001), TC:HDL cholesterol ratio (0.147; 95% CI: 0.284, 0.010; P = 0.036), non-HDL cholesterol (0.194 mmol/L; 95% CI: 0.314, 0.073 mmol/L; P = 0.002), and Framingham cardiovascular disease (CVD) risk (0.474; 95% CI: 0.900, 0.049, P = 0.029). Changes in HDL cholesterol, triglycerides, glucose, and insulin did not differ between treatment groups (P > 0.05). Lipid treatment effects were not significantly modified by age, sex, BMI, or hypertension treatment. There were no major adverse events, but both treatments transiently increased gastrointestinal symptoms. Conclusions Consuming a beverage containing 1 g high-MW OBG 3 times daily for 4 wk significantly reduced LDL cholesterol by ∼6% and CVD risk by ∼8% in healthy adults with LDL cholesterol between 3 and 5 mmol/L.This trial was registered at clinicaltrials.gov as NCT03911427.

Prebiotics are nondigestible food agents that stimulate the growth of bacteria in the gut, whereas probiotics are live microorganisms that replace or restore beneficial bacteria in the digestive tract. Both agents have been shown to have beneficial qualities within the microbiota-gut-brain axis, but the behavioural effects of prebiotics have been less studied than probiotics. Whereas several studies have shown that prebiotics reduce inflammation and modulate anxiety in animals that are injected with lipopolysacccharides or chronically stressed animals, respectively, it is not yet known how they affect a healthy organism. Here, we tested the behavioural effects of galacto-oligosaccharides and beta glucan as a commercially available prebiotic blend in healthy, naïve Sprague-Dawley rats. We used the open field test and elevated plus maze to assess anxiety-like behaviour in controls and in rats that ingested the prebiotic blend in their drinking water. We also used the Morris Water Maze to assess spatial memory performance in controls and prebiotic treated rats. Rats treated with prebiotics spent more time in the intermediate zone of the open field test and in the open arms of the elevated plus maze, and exhibited a shorter latency to enter each of these zones. No significant differences between groups were found in the Morris Water Maze. Our results suggest that whereas prebiotics significantly reduced anxiety-like behaviours, it had no effect on spatial memory performance. Altogether, our data indicate that commercially available prebiotic beta glucan blends have anxiolytic effects in healthy rats.

The current toolbox of cell wall-directed molecular probes has been pivotal for advancing basic and application-oriented plant carbohydrate research; however, it still exhibits limitations regarding target diversity and specificity. Scarcity of probes targeting intramolecular associations between cell wall polymers particularly hinders our understanding of the cell wall microstructure and affects the development of effective means for its efficient deconstruction for bioconversion. Here we report a detailed characterization of a cellulose-binding DNA aptamer CELAPT MINI using a combination of various in vitro biochemical, biophysical, and molecular biology techniques. Our results show evidence for its high specificity towards long non-substituted β-(1-4)-glucan chains in both crystalline and amorphous forms. Fluorescent conjugates of CELAPT MINI are applicable as in situ cellulose probes and are well suited for various microscopy techniques, including super-resolution imaging. Compatibility of fluorescent CELAPT MINI variants with immunodetection of cell wall matrix polymers enabled them simultaneously to resolve the fibrillar organization of complex cellulose-enriched pulp material and to quantify the level of cellulose masking by xyloglucan and xylan. Using enzymatically, chemically, or genetically modulated Brachypodium internode sections we showed the diversity in cell wall packing among various cell types and even cell wall microdomains. We showed that xylan is the most prominent, but not the only, cellulose-masking agent in Brachypodium internode tissues. These results collectively highlight the hitherto unexplored potential to expand the cell wall probing toolbox with highly specific and versatile in vitro generated polynucleotide probes.

The integrity of the epidermal barrier and the maintenance of barrier homeostasis depend on the dynamic balance between the proliferation and differentiation of keratinocytes. Calcium (Ca2+) plays a crucial role in maintaining a balance of these two processes as well as in the formation of an epidermal permeability barrier. In this study, we showed that topical application of oat β-glucan (OG) could ameliorate epidermal hyperplasia and accelerate the recovery of the epidermal barrier by promoting epidermal differentiation. Mechanistic studies revealed a positive interaction between OG and the dectin-1 receptor, and this interaction could lead to an upregulated expression of the calcium-sensing receptor (CaSR) via activation of the downstream ERK and p38 pathways. This consequently increased the sensitivity of keratinocytes to extracellular Ca2+ under the condition of calcium loss following the disruption of the epidermal barrier, resulting in the maintenance of normal keratinocyte differentiation in the epidermis, and ultimately promoting the recovery of the epidermal barrier. These findings clearly demonstrated the healing effect of OG on a physically damaged epidermal barrier. Thus, OG could be considered a valuable component in the development of skin repair agents.

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.

β-1,3-glucans, natural polysaccharide groups, exert immunomodulatory effects to improve the innate response and disease resistance in aquatic species and mammals. However, this β-glucan stimulant is yet to be assayed in swimming crab (Portunus trituberculatus) hemocytes. In this study, we explored the immunomodulatory effect of β-1,3-glucans (derived from Euglena gracilis) via in vitro 24 h stimulation assays in swimming crab hemocytes. We found that this algal β-1,3-glucans in crab hemocytes significantly elevated cellular enzymes related parameters, including phenoloxidase (PO), lysozyme, acid phosphatase (ACP) activities, and superoxide anion generation (O2−) rate both at intracellular (P 0.05). β-glucan significantly influenced (P

In this study, four extraction methods, including ultrasonic extraction (UE), hot water extraction (HWE), microwave extraction (ME), and microwave-assisted ultrasonic extraction (MUE) were utilized to extract β-glucan from hull-less barley bran. Extraction yields and physicochemical properties of β-glucans extracted by different methods were investigated. The MUE displayed a highest extraction yield (2.16%) within shorter extraction time. Besides, β-glucans extracted by MUE (MUE-G) had higher number-average molecular weight (Mn) (3.415 × 105), whereas β-glucans extracted by UE (UE-G) showed lower Mn (2.257 × 105) as compared to other methods. Accordingly, apparent viscosity of MUE-G was highest, while water solubility index of UE-G was highest (34.18-88.81%) at tested temperature ranges (25-95 °C). The MUE-G shower stronger foam stability and emulsifying properties and weaker foaming capability, while UE-G exhibited stronger foaming capability. The foaming capability and emulsifying properties of β-glucan products were better in neutral solutions (pH = 7) than in the acidic (pH = 4) and alkaline (pH = 9).

The production of curdlan oligosaccharides, a multifunctional and valuable carbohydrate, by hydrolyzing polysaccharides is of great interest. The endo-β-1,3-glucanase derived from Trichoderma harzianum was expressed in Pichia pastoris with three commonly used promoters (AOX1, GAP and FLD1). The purified recombinant endo-β-1,3-glucanase expressed by Pichia pastoris with GAP promoter displayed high specific activity at pH 5.5 and 50 °C. Thereafter, a co-culture system of Pichia pastoris GS115 (GAP promoter) and Agrobacterium sp. was constructed in which Agrobacterium sp.-metabolized curdlan can be directly hydrolyzed by Pichia pastoris-secreted endo-β-1,3-glucanase to produce functional curdlan oligosaccharides. The co-culture conditions were optimized and the process was carried out in a 7-L bioreactor. The maximum yield of curdlan oligosaccharides reached 18.77 g/L with 3–10 degrees of polymerization. This study presents a novel and easy curdlan oligosaccharide production strategy that can replace traditional sophisticated production procedures and could potentially be implemented for production of other oligosaccharides.

Background: To date, several researchers have investigated the association between dietary fibre consumption and satiety. However, there is no study that includes both inulin and β-glucan to compare energy intake (EI) and satiety ratings. Aim: The current study investigated the effects of two dietary fibres, β-glucan and inulin, on satiety and food intake. Methods: The study was carried out among 24 woman over 18 years of age. The dietary fibres β-glucan (6 g/day) or inulin (6 g/day) were consumed by participants for five weeks. On the first and fifth week visits, the participants consumed a standard breakfast followed by an ad libitum test meal. Appetite was assessed using visual analogue scales (VAS) before and after breakfast. EI was measured at the test meal using plate waste. Results: Both dietary fibres significantly reduced the VAS scores of hunger, prospective food consumption and desire to eat, and increased satiety compared with the control group. However, the area under curve data for the VAS scores did not exhibit a significant difference. Significant reductions in EI and anthropometric values between the first and fifth week measures were observed in both dietary fibre groups. Statistically significant changes occurred in the body weight [-1.25 (1.27) kg], body mass index [-0.41 (0.42) kg/m2], waist circumference [-1.25 (1.04) cm] and waist/hip ratio [-0.01(0.01)] in the β-glucan group, whereas a statistically significant change occurred in body fat percentage in the inulin group [-2.16% (7.49)]. Conclusions: Overall, these findings demonstrate that the participants consuming β-glucan over the course of the five weeks had less EI, felt less hunger and had more satiety.

Curdlan (CN)-doped montmorillonite/poly(N-isopropylacrylamide-co-N,N'-methylene-bis-acrylamide) [CN/MT/P(NIPA-co-MBA)] smart nanocomposites (NCs) were developed for efficient erlotinib HCl (ERL) delivery to lung cancer cells. The placebo NCs demonstrated excellent biodegradability, pH/thermo-responsive swelling profiles and declined molar mass (M¯c) between the crosslinks with increasing temperature. The XRD, FTIR, DSC, TGA, and SEM analyses revealed the architectural chemistry of these NC scaffolds. The NCs loaded with ERL (F-1-F-3) displayed acceptable diameter (734-1120 nm) and zeta potential (+1.16 to -11.17 mV), outstanding drug entrapping capability (DEE, 78-99%) and sustained biphasic ERL elution patterns (Q8h, 53-91%). The ERL release kinetics of the optimal matrices (F-3) obeyed Higuchi model and their transport occurred through anomalous diffusion. The mucin adsorption behaviour of these matrices followed Freudlich isotherms. As compared to pure ERL, the formulation (F-3) displayed an improved anti-proliferative potential and induced apoptosis more effectively on A549 cells. Thus, the CN-doped smart NCs could be utilized as promising drug-cargoes for lung cancer therapy.

Background: Regulating the polarization of macrophages to antitumor M1 macrophages is a promising strategy for overcoming the immunosuppression of the tumor microenvironment for cancer therapy. Ferumoxytol (FMT) can not only serve as a drug deliver agent but also exerts anti-tumor activity. β-glucan has immuno-modulating properties to prevent tumor growth. Thus, a nanocomposite of FMT surface-coated with β-glucan (FMT-β-glucan) was prepared to explore its effect on tumor suppression. Methods: Male B16F10 melanoma mouse model was established to explore the antitumor effect of FMT-β-glucan. The viability and apoptotic rates of B16F10 cells were detected by cell counting kit-8 and Annexin-V/PI experiments. The levels of M1 markers were quantified by quantitative reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay. Phagocytic activity and intracellular reactive oxygen species (ROS) in macrophages were evaluated by the neutral red uptake assay and flow cytometry, respectively. Small interfering RNA (siRNA) transfection was applied to knock down the Dectin-1 gene in RAW 264.7 cells. Results: FMT-β-glucan suppressed tumor growth to a greater extent and induced higher infiltration of M1 macrophages than the combination of FMT and β-glucan (FMT+β-glucan) in vivo. In vitro, supernatant from FMT-β-glucan-treated RAW 264.7 cells led to lower cell viability and induced more apoptosis of B16F10 cells than that from the FMT+β-glucan group. Moreover, FMT-β-glucan boosted the expression of M1 type markers, and increased phagocytic activity and ROS in RAW 264.7 cells. Further research indicated that FMT-β-glucan treatment promoted the level of Dectin-1 on the surface of RAW 264.7 cells and that knockdown of Dectin-1 abrogated the phosphorylation levels of several components in MAPK and NF-κB signaling. Conclusion: The nanocomposite FMT-β-glucan suppressed melanoma growth by inducing the M1 macrophage-activated tumor microenvironment.

To test the hypothesis that β -glucan enhances protective qi (PQi), an important Chinese medicine (CM) concept which stipulates that a protective force circulates throughout the body surface and works as the first line of defense against “external pernicious influences”. A total of 138 participants with PQi deficiency (PQD) were randomized to receive β -glucan (200 mg daily) or placebo for 12 weeks. Participants’ PQi status was assessed every 2 weeks via conventional diagnosis and a standardized protocol from which a PQD severity and risk score was derived. Indices of participants’ immune and general health status were also monitored, including upper respiratory tract infection (URTI), saliva secretory IgA (sIgA), and self-reported measures of physical and mental health (PROMIS). PQi status was not significantly different between the β -glucan and placebo treatment groups at baseline but improved significantly in the β -glucan (vs. placebo) group in a time-dependent manner. The intergroup differences [95% confidence interval (CI)] in severity score (scale: 1–5), risk score (scale: 0–1), and proportion of PQD participants (%) at finish line was 0.49 (0.35–0.62), 0.48 (0.35–0.61), and 0.36 (0.25–0.47), respectively. Additionally, β -glucan improved URTI symptom (scale: 1–9) and PROMIS physical (scale: 16.2–67.7) and mental (scale: 21.2–67.6) scores by a magnitude (95% CI) of 1.0 (0.21–1.86), 5.7 (2.33–9.07), and 3.0 (20.37–6.37), respectively, over placebo. β -glucan ameliorates PQi in PQD individuals. By using stringent evidence-based methodologies, our study demonstrated that Western medicine-derived remedies, such as β -glucan, can be employed to advance CM therapeutics. (ClinicalTrial.Gov registry: NCT03782974)

Abstract β-Glucan phosphorylases are carbohydrate-active enzymes that catalyze the reversible degradation of β-linked glucose polymers, with outstanding potential for the biocatalytic bottom-up synthesis of β-glucans as major bioactive compounds. Their preference for sugar phosphates (rather than nucleotide sugars) as donor substrates further underlines their significance for the carbohydrate industry. Presently, they are classified in the glycoside hydrolase families 94, 149, and 161 (www.cazy.org). Since the discovery of β-1,3-oligoglucan phosphorylase in 1963, several other specificities have been reported that differ in linkage type and/or degree of polymerization. Here, we present an overview of the progress that has been made in our understanding of β-glucan and associated β-glucobiose phosphorylases, with a special focus on their application in the synthesis of carbohydrates and related molecules. Key points • Discovery, characteristics, and applications of β-glucan phosphorylases. • β-Glucan phosphorylases in the production of functional carbohydrates.

Glycan microarrays have played important roles in detection and specificity assignment of glycan recognition by proteins. However, the size and diversity of glycan libraries in current microarray systems are small compared to estimated glycomes, and these may lead to missed detection or incomplete assignment. For microarray construction, covalent and noncovalent immobilization are the two types of methods used, but a direct comparison of results from the two platforms is required. Here we develop a chemical strategy to prepare lipid-linked probes from both naturally derived aldehyde-terminating and synthetic amino-terminating glycans that addresses the two aspects: expansion of sequence-defined glycan libraries and comparison of the two platforms. We demonstrate the specific recognition by plant and mammalian lectins, carbohydrate-binding modules and antibodies and the overall similarities from the two platforms. Our results provide new knowledge on unique glycan-binding specificities for the immune receptor Dectin-1 toward β-glucans and the interaction of rotavirus P[19] adhesive protein with mucin O-glycan cores.

β-glucans are linear polysaccharides of d-glucose monomers linked through β-glycosidic bonds and are widely present in nature. Different sources lead to their structural differences. β-glucan has long been acknowledged to be a safe and functional component. Its biological activities include lipid-lowering, hypoglycemic, antitumor and immune regulation etc. A large number of studies have shown that soluble β-glucan can bind to their receptors on the surface of immune cells, activates the pro-inflammatory response of innate immune cells, and enhances the host's antitumor defense. A variety of soluble β-glucans have been widely used in clinical antitumor studies as an immunostimulant to treat the cancer patient. In this paper, we reviewed the molecular structure, antitumor immune activities, structure-activity relationship and clinical trials of soluble β-glucans in order to provide the overall scene of β-glucans as immunostimulant to fight the cancer.

β-Glucan from Saccharomyces cerevisiae has been described to be effective antioxidants, but the specific antioxidation mechanism of β-glucan is unclear. The objectives of this research were to determine whether the β-glucan from Saccharomyces cerevisiae could regulate oxidative stress through the Dectin-1/Nrf2/HO-1 signaling pathway in lipopolysaccharides (LPS)-stimulated RAW264.7 cells. In this study, we examined the effects of β-glucan on the enzyme activity or production of oxidative stress indicators in LPS-stimulated RAW264.7 cells by biochemical analysis and the protein expression of key factors of Dectin-1/Nrf2/HO-1 signaling pathway by immunofluorescence and western blot. The biochemical analysis results showed that β-glucan increased the LPS-induced downregulation of enzyme activity of intracellular heme oxygenase (HO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) while decreasing the production of reactive oxygen species (ROS) and malondialdehyde (MDA). Furthermore, immunofluorescence results showed that β-glucan can activate the nuclear factor erythroid 2-related factor 2 (Nrf2). The antioxidant mechanism study indicated that β-glucan activated dendritic-cell-associated C-type lectin 1 (Dectin-1) receptors mediated Nrf2/HO-1 signaling pathway, thereby downregulating the production of ROS and thus produced the antioxidant effects in LPS-stimulated RAW 264.7 cells. In conclusion, these results indicate that β-glucan potently alleviated oxidative stress via Dectin-1/Nrf2/HO-1 in LPS-stimulated RAW 264.7 cells.

The use of particulate adjuvants offers an interesting method for enhancing and modulating the immune responses elicited by vaccines. Aluminum salt (Alum) is one of the most important immune adjuvants approved by the Food and Drug Administration for use in humans because of its safety and efficacy, but it lacks the capacity to induce strong cellular and mucosal immune responses. In this study, we designed an antigen delivery system that combines aluminum salts with β-glucan particles. The β-glucan-aluminum particles (GP-Al) exhibited a highly uniform size of 2-4 μm and could highly specifically target antigen-presenting cells (APCs) and strongly induce dendritic cell (DC) maturation and cytokine secretion.

Heterologous endo-xanthanase (EX) from the thermophilic planktomycete Thermogutta terrifontis strain was obtained using Penicillium verruculosum 537 (ΔniaD) expression system with the cellobiohydrolase 1 gene promoter. Homogeneous EX with a molecular weight of 23.7 kDa (pI 6.5) was isolated using liquid chromatography methods. This xanthan degrading enzyme also possesses the enzymatic activity towards CM-cellulose, β-glucan, curdlan, lichenan, laminarin, galactomannan, xyloglucan but not towards p-nitrophenyl derivatives of β-D-glucose, mannose and cellobiose. The temperature and pH optima of EX were 55°C and 4.0, respectively; the enzyme exhibited 90% of its maximum activity in the temperature range 50-60°C and pH 3-5.

This study was conducted to investigate the effects of germination on the bioactive phytochemicals in the barley variety ‘Betaone’, which has high β-glucan content. Betaone barley seeds were germinated for 24, 48, 72, and 96 h at 25 °C in a growth chamber. As the germination period progressed, crude protein, crude fat, and crude ash levels increased, while starch content decreased. β-Glucan content significantly decreased during the germination period. However, after 96 h of germination, it was still 4.31%, which is similar to the amount found in ordinary barley varieties. The α- and β-amylase activities in Betaone barley increased, thereby significantly decreasing pasting viscosities (p ≤ 0.05), as germination progressed. The water absorption index increased in the early germination stage, subsequently decreasing as germination progressed. While the water solubility index fell in the first stage of germination, it subsequently increased as germination progressed. Oil absorption decreased as germination progressed. Bioactive compounds, in particular the total phenolic (122.84–322.67 μg/g), total flavonoid (32.20–124.09 μg/g), and GABA content (176.94–212.64 μg/g), increased as germination progressed. The antioxidative properties mainly DPPH and ABTS radical scavenging activity also increased during the germination period. Therefore, these findings could be a useful method for improving new products with enhanced bioactive phytochemicals.

In this study, we increased β-glucan production from brewer’s yeast, Saccharomyces carlsbergensis RU01, by using tannic acid. High-pressure freezing and transmission electron microscopy (HPF-TEM) revealed that the yeast cell wall obtained from yeast malt (YM) medium supplemented with 0.1% w/v tannic acid was thicker than that of yeast cultured in YM medium alone. The production of β-glucan from S. carlsbergensis RU01 was optimized in 3% w/v molasses and 0.1% w/v diammonium sulfate (MDS) medium supplemented with 0.1% w/v tannic acid. The results showed that MDS medium supplemented with 0.1% w/v tannic acid significantly increased the dry cell weight (DCW), and the β-glucan production was 0.28±0.01% w/v and 11.99±0.04% w/w. Tannic acid enhanced the β-glucan content by up to 42.23%. β-Glucan production in the stirred tank reactor (STR) was 1.4-fold higher than that in the shake flask (SF) culture. Analysis of the β-glucan composition by Fourier transform infrared (FTIR) spectroscopy showed that the β-glucan of S. carlsbergensis RU01 cultured in MDS medium supplemented with 0.1% w/v tannic acid had a higher proportion of polysaccharide than that of the control. In addition, β-glucans from brewer’s yeast can be used as prebiotic and functional foods for human health and in animal feed.

In order to solve the antibiotic resistance, the research on antibiotic substitutes has received an extensive attention. Many studies have shown that β-glucan and mannan from yeast cell wall have the potential to replace antibiotics for the prevention and treatment of animal diseases, thereby reducing the development and spread of antibiotic-resistant bacterial pathogens. β-Glucan and mannan had a variety of biological functions, including improving the intestinal environment, stimulating innate and acquired immunity, adsorbing mycotoxins, enhancing antioxidant capacity, and so on. The biological activities of β-glucan and mannan can be improved by chemically modifying its primary structure or reducing molecular weight. In this paper, the structure, preparation, modification, and biological activities of β-glucan and mannan were reviewed, which provided future perspectives of β-glucan and mannan.

To determine the effect of oat β‑glucan (OBG) on acute glucose and insulin responses and identify significant effect modifiers we searched the MEDLINE, EMBASE, and Cochrane databases through October 27, 2020 for acute, crossover, controlled feeding trials investigating the effect of adding OBG (concentrate or oat-bran) to carbohydrate-containing test-meals compared to comparable or different carbohydrate-matched control-meals in humans regardless of health status. The primary outcome was glucose incremental area-under-the-curve (iAUC). Secondary outcomes were insulin iAUC, and glucose and insulin incremental peak-rise (iPeak). Two reviewers extracted the data and assessed risk-of-bias and certainty-of-evidence (GRADE). Data were pooled using generic inverse-variance with random-effects model and expressed as ratio-of-means with [95% CIs]. We included 103 trial comparisons (N = 538). OBG reduced glucose iAUC and iPeak by 23% (0.77 [0.74, 0.81]) and 28% (0.72 [0.64, 0.76]) and insulin by 22% (0.78 [0.72, 0.85]) and 24% (0.76 [0.65, 0.88]), respectively. Dose, molecular-weight, and comparator were significant effect modifiers of glucose iAUC and iPeak. Significant linear dose-response relationships were observed for all outcomes. OBG molecular-weight >300 kg/mol significantly reduced glucose iAUC and iPeak, whereas molecular-weight p = 0.03) and iPeak (39 vs 25%, p

Anti-cancer T-cell responses are often halted due to the immune-suppressive micro-environment, in part related to tumor-associated macrophages. In the current study, we assessed indigestible β-glucans (oatβG, curdlan, grifolan, schizophyllan, lentinan, yeast whole glucan particles (yWGP), zymosan and two additional yeast-derived β-glucans a and b) for their physicochemical properties as well as their effects on the plasticity of human monocyte-derived macrophages that were polarized with IL-4 to immune-suppressive macrophages. Beta-glucans were LPS/LTA free, and tested for solubility, molecular masses, protein and monosaccharide contents. Curdlan, yeast-b and zymosan re-polarized M(IL-4) macrophages towards an M1-like phenotype, in particular showing enhanced gene expression of CCR7, ICAM1 and CD80, and secretion of TNF-α and IL-6. Notably, differential gene expression, pathway analysis as well as protein expressions demonstrated that M(IL-4) macrophages treated with curdlan, yeast-b or zymosan demonstrated enhanced production of chemo-attractants, such as CCL3, CCL4, and CXCL8, which contribute to recruitment of monocytes and neutrophils. The secretion of chemo-attractants was confirmed when using patient-derived melanoma-infiltrating immune cells. Taken together, the bacterial-derived curdlan as well as the yeast-derived β-glucans yeast-b and zymosan have the unique ability to preferentially skew macrophages towards a chemo-attractant-producing phenotype that may aid in anti-cancer immune responses. Electronic supplementary material The online version of this article (10.1007/s00262-020-02707-4) contains supplementary material, which is available to authorized users.

Background: Chronic stress elevates the cortisol beyond normal levels, which affects cognition including learning & memory. This injurious effect is primarily mediated via over excitation of metabotropic glucocorticoid receptors (mGR). Methods: The present study was aimed to appraise the neuroprotective effects of naturally occurring molecule β-1,3-glucan by interfering with stress-cortisol-mGR axis. Our data of virtual screening (in silico) exhibited the promising interactions of β-glucan with the mGR. Therefore, the study was extended to evaluate its efficacy (2.5, 5 and 10 mg/kg/ i.p) in an animal model of chronic unpredictable mild stress (CUMS, 28 days) induced memory impairment. Results: Results of the current study revealed the β-glucan provided dose dependent protection against deleterious effects of stress on learning and memory associated parameters observed in Morris water maze (MWM) task. At higher tested doses, it has also significantly antagonized the stress induced weight loss and corticosterone elevation.

β-1,3-D-glucan (BG) activates innate immunity and enhances immune responses. Fungi, such as mushrooms, produce a relatively large amount of BG, the structure and molecular weight of which varies depending on the species of fungi. This study was conducted to develop a detection probe for quantifying or detecting BG from fungi using BG-binding proteins. The binding properties of a new β-glucan recognition protein (BGRP) against various BGs were compared. With reference to the amino acid sequences of BGRP in insects, an artificial BGRP (supBGRP) was designed with higher production efficiency using gene recombination technology. SupBGRP was produced in Escherichia coli with high efficiency, and its reactivity with BG from fungi was the highest among the BG-binding proteins examined. SupBGRP exhibited high reactivity with 1,6-branched BG and will be useful for the quantification and detection of fungal BG.

The impact of preparation conditions including heating temperature (from 60 °C to 90 °C) and drying temperatures (from 25 °C to 90 °C) on the properties of pure curdlan film and konjac glucomannan (KGM) and curdlan blend films were analyzed. Microstructure analysis indicated the KGM addition could significantly improve the relatively poor film-forming property of curdlan. FTIR and X-ray analysis showed that at high heating temperature 90 °C, molecular interaction might be enhanced in the films due to the stretched structure of curdlan and dissociation of curdlan bundles or triple-helix structure. This was supported by the changes in the mechanical property, surface hydrophobicity, moisture barrier, and moisture tolerance property. The impacts of drying temperature were some different for the curdlan film and KGM/curdlan blend film, and were explained from the molecular hydrophilicity-hydrophobicity, compactness of the films, curdlan conformation, and molecular interaction. This work guided biodegradable film production especially with curdlan added.

The hull-less barley (Qingke) is widely planted as a staple food crop in the Tibetan area, China, and the grains contains high content of β-glucan (BG). The mechanisms of BG synthesis and accumulation in qingke has not been studied at the protein level. This study characterized the proteins associated with BG synthesis and accumulation during qingke seed development. The proteome profiles of qingke seeds taken at 20, 30, and 40 days after flowering were compared using the TMT-based quantitative proteomics. A total of 4283 proteins were identified, with 759 being differentially expressed (DEPs) throughout seed development. Comparisons of protein expression pattern, functions, and pathway enrichment tests highlight cell wall modification, carbon and energy metabolism, polysaccharide metabolism, post-transcriptional modifications, and vesicular transport as critical biological processes related to qingke BG accumulation. Furthermore, induction of starch synthase, starch branching enzyme, pectin acetyl esterases, beta-glucosidases, beta-amylases, 1,4-beta-xylan, xyloglucan, α-amylase inhibitors, and glycosyltransferases underpinned BG synthesis. The results also indicated that the proteins involved in glycolytic, gluconeogenesis, and glyoxylate bypass pathways provided energy and reducing power for BG storage. Parallel reaction monitoring (PRM) and quantitative real-time PCR (qPCR) analyses confirmed the expression profile of the proteins obtained by TMT-based proteomics. The current results provided an insight into the mechanisms of BG synthesis and accumulation during qingke seed development.

Curdlan is a neutral linear exopolysaccharide produced by Agrobacterium spp. under nitrogen-limiting conditions. In this study, we explored the role of glnA in curdlan biosynthesis in Agrobacterium sp. CGMCC 11546. The curdlan production of the ΔglnA strain was impaired, decreasing by 93% compared with that of the wild-type strain after 96 h fermentation. Analysis of fermentation profiles revealed that cell growth and utilization of carbon and nitrogen sources were impaired in the ΔglnA strain. Transcriptome analysis indicated that various of genes involved in curdlan biosynthesis were downregulated after 24 h fermentation in the ΔglnA strain, particularly genes involved in heme synthesis and the electron transport chain, which are essential for energy generation. Metabolomics analysis revealed flavin adenine dinucleotide (FAD) and adenosine diphosphate (ADP) accumulation in the ΔglnA strain, suggesting insufficient energy supply. Furthermore, glnA overexpression led to an 18% increase in the curdlan yield of the ΔglnA mutant compared with that of the wild-type strain after 96 h fermentation. Taken together, the findings demonstrate that glnA plays a vital role in curdlan biosynthesis by supplying ATP via regulating the expression of genes involved in heme synthesis and the electron transport chain.

Deoxynivalenol (DON) is the most common trichothecene distributed in food and feed. So far, much work has focused on investigating the cytotoxicity of DON, while there is few researches aimed at intervening in the toxic impacts on humans and livestock posed by DON. The objective of this study is to investigate the underlying mechanism of biomacromolecules mannan/β-glucans from yeast cell wall (BYCW) for their potency to impede the cytotoxicity and apoptosis caused by DON with porcine jejunum epithelial cell lines (IPEC-J2) used as a cell injury model. We analyzed the cell morphology, cell activity, oxidative stress, fluorescence intensity and expressions of proteins relevant to autophagy, apoptosis and PI3K-AKT-mTOR signaling pathway by using inverted microscopy, MTS, reactive oxygen species (ROS), glutathione (GSH) and malondialdehyde (MDA) assay, Annexin V-FITC / propidium iodide (PI) double staining and Western blot assay. The consequent data demonstrated that in the presence of BYCW, the cell morphology and activity were relatively ameliorated and that the oxidation damage was attenuated with DON-induced autophagy concomitantly decreased, which, furthermore, was found involved in the positive regulation on PI3K-AKT-mTOR signaling pathway by BYCW. In a word, BYCW possess an ability to repress the cytotoxicity and apoptosis induced by DON through the inhibition of autophagy via activating PI3K-AKT-mTOR signaling pathway.

Green and functional bio based adsorbents based on naturally derived polysaccharides have attracted considerable interest owing to their non-toxicity, biodegradability, flexible design, and wide origins. Here, smart polyelectrolyte complex (PEC SC1-SC4) hydrogels were developed by self-assembling of different ratios of salecan and chitosan lactate (CL) for clean-up of nickel ion (Ni2+) from wastewater. Preparation process was rapid and eco-friendly, without any toxic cross-linkers. The electrostatic attractions between polysaccharides were studied by FT-IR, XRD, XPS, and TGA. Particularly, the content of salecan and CL could be precisely modulated to tailor the swelling ability, micromorphology, and stiffness of the hydrogels. Ni2+ adsorption onto the hydrogels was dependent on salecan/CL ratio, pH, initial ion concentration, and contact time. SC4 showed the highest Ni2+ uptake, but it was too brittle. SC3 was selected for absorption studies. The equilibrium adsorption data commendably matched the pseudo-second-order and Langmuir models, demonstrating monolayer chemical adsorption mechanisms. The maximum Ni2+ adsorption derived from Langmuir model was 414.9 mg/g, superior to many reported Ni2+ adsorbents. Most strikingly, SC3 performed good recyclability, and the adsorption capacity still kept 95.3% even after five adsorption/desorption cycles. Hopefully, the prepared SC3 hydrogel is a potential agent for treatment of wastewater contaminated with Ni2+ ion.

Oligo-deoxyadenylic acid (dAX) forms a novel 1:2 triple-helix with β-1,3-d-glucan schizophyllan (SPG). We found that dAX meticulously selects the most suitable length of SPG to bind; for example, dA30 only complexes with a short SPG chain having 30, 60, or 90 main-chain glucoses, and they can be easily isolated with each other. This study demonstrated such a novel stoichiometric complex formation by using gel permeation chromatography coupled with multi-angle light scattering and synchrotron small-angle X-ray scattering. These oligo-DNA/polysaccharide complexes can be used as a tool for delivering therapeutic oligonucleotides to immunocytes that express the β-1,3-d-glucan receptors. The present study provides a robust platform technique to characterize them in terms of modern regulatory science of nanomedicines, which is requisite to transfer drug candidates into clinical trial. Our findings are important for characterizing these complexes as well as for providing a new insight into nucleotide and saccharide chemistry.

Barley (Hordeum vulgare L.) is an important cereal crop and ranks fourth among the total cereals production but very little of this grain is used as human food. However, these days it is gaining popularity as "functional grain" because it contains higher amounts of bioactive compounds including β-glucan (4-11%) and phytochemicals. The health benefits of barley β-glucan and other bioactive compounds have been well documented. β-Glucan is the most unique polysaccharide of barley which is associated with numerous health benefits including reduction of cholesterol, manage post postprandial blood glucose levels and acts as an anti-cancerous agent. Since food grains including barley are consumed after processing and it may alter the solubility, molecular weight and extractability of β-glucan affecting the health benefits. Therefore, it is important to know the processing effects on β-glucan to confirm such health claims for barley. Most of the review papers published are focused on the health benefits of β-glucan. To the best of our knowledge, no comprehensive report is available on the effects of barley processing on β-glucan content, molecular weight and β-glucan extractability. The present article reviews the literature on processing effects on barley β-glucan.

Vaccination is one of the strategies for preventing Vibrio harveyi infection in marine-cultured animals. In this study, we prepared a formalin-killed cells of V. harveyi ZJ0603 vaccine (FKC) combined with β-glucan to immune pearl gentian grouper. The results indicated that the expression levels of IgM, TNF-α, MHC-Iα, IL-1β and IL-16 significantly increased in the spleen of the vaccinated fish. Antibody titers, activities of lysozyme and superoxide dismutase were significantly prompted in blood of the vaccinated fish. After 35 d post-vaccination, all fish were challenged intraperitoneally by virulent V. harveyi, and the relative percentage of survival (RPS) of FKC+β-glucan, FKC, β-glucan and PBS were 68 ± 5.7%, 55 ± 8.5%, 42 ± 7.5% and 32 ± 6.9%, respectively. These results demonstrated that β-glucan could be as a potential adjuvant of FKC and provide good protective effect against V. harveyi infection in the pearl gentian grouper culture.