Β-glucan Levels Research Articles

Hyphal swelling induced in the phagosome of macrophages

Macrophages play critical protective roles as sentinels of the innate immune system against fungal infection. It is therefore important to understand the dynamics of the interaction between these phagocytes and their fungal prey. We show here that many of the hyphal apices formed by Candida albicans within the macrophage ceased elongating, and apical and sub-apical hyphal compartments became swollen. Swollen hyphal cell compartments assimilated less Lysotracker-Red than non-swollen compartments, suggesting they had enhanced viability. Staining with florescent dyes suggested that there were higher levels of β-glucan and chitin in internalized fungal filaments compared to non-internalized hyphae, suggesting active cell wall remodelling within macrophages. These observations suggest that the stresses imposed by macrophages upon the fungus lead to changes in cell wall composition, inhibition of polarised growth and the induction of swelling in hyphal compartments, and that this can prevent or delay loss of viability of hyphal cells within the phagocyte.

Comparative Chemical Analysis and Bioactive Properties of Aqueous and Glucan-Rich Extracts of Three Widely Appreciated Mushrooms: Agaricus bisporus (J.E.Lange) Imbach, Laetiporus sulphureus (Bull.) Murill and Agrocybe aegerita (V. Brig.) Vizzini.

Herein we describe the antioxidant, antimicrobial, antibiofilm, anti-inflammatory and wound-healing potential of aqueous and polysaccharide extracts from three widely appreciated mushrooms: Agrocybe aegerita, Laetiporus sulphureus and Agaricus bisporus. Moreover, we present their detailed phenolic, polysaccharide and protein profiles and ATR-FTIR spectra. The study found that polysaccharide extracts (PEs) from mushrooms had higher total and β-glucan levels than aqueous extracts (AEs), with A. aegerita showing the highest content. L. sulphureus had a higher total protein content, and A. aegerita AE had the highest phenolic content. Our results indicate that all the tested extracts have high potential regarding their bioactive properties, with A. aegerita being the most promising one. Namely, the antibacterial activity assay showed that the development of the skin-infection-causing agent, Staphylococcus aureus, was inhibited with a minimal inhibitory concentration of 4.00 mg/mL and minimal bactericidal concentration of 8.00 mg/mL, while the results regarding wound healing showed that, over the course of 24 h, the A. aegerita extract actively promoted wound closure in the HaCaT keratinocyte cell line model. The anti-inflammatory activity results clearly showed that when we used S. aureus as an inflammation-inducing agent and the A. aegerita aqueous extract in treatment, IL-6 levels reduced to the level of 4.56 pg/mL. The obtained data suggest that the tested mushroom extracts may serve as a source of bioactive compounds, with potential applications in the cosmeceutical, pharmaceutical and food industries. Furthermore, potential skin preparations carefully crafted with mushroom extract may help restore the skin's barrier function, decrease the probability of staph infections and minimize skin irritation.

Effect of Dietary β-Glucan on Growth Performance, Antioxidant Responses, and Immunological Parameters of Coral Trout (Plectropomus leopardus)

Although β-glucan has diverse benefits for fish health, the potential adverse impacts of excessive supplementation are poorly understood. This study investigated the optimal dosage of β-glucan for coral trout and explored the adverse effects of excessive supplementation. The results revealed that moderate β-glucan supplementation (1) significantly enhanced the weight gain rate and specific growth rate (SGR); (2) significantly improved the intestinal villus length (0.10%), muscle thickness (0.05–0.15%), and α-amylase and chymotrypsin activities (0.05–0.15%); (3) significantly increased liver catalase (CAT), glutathione reductase (GR), alkaline phosphatase, complement 3, immunoglobulin M (IgM), lysozyme, serum superoxide dismutase, CAT, glutathione peroxidase, GR, total antioxidant capacity, acid phosphatase, complement 4, and IgM activities and significantly reduced malondialdehyde contents; (4) upregulated genes in the liver associated with copper-zinc superoxide dismutase (SOD-1), manganese superoxide dismutase (SOD-2), CAT, GSH-Px1a, ACP6, AKP, LZ-c, IgM, C3, and C4-b. However, 0.20% β-glucan significantly inhibited the growth performance of coral trout compared with 0.10% β-glucan. Thus, 0.10% β-glucan represents the optimal dosage for promoting growth, antioxidant activity, and immune responses in coral trout, while higher β-glucan levels weakened these beneficial effects. With an SGR established by a cubic regression analysis, the optimal level of β-glucan for maximal growth of coral trout is 0.082%. This study provides new insights into the health impacts of β-glucan on fish.

Improvement in Storage Stability and Physicochemical Properties of Whole-Grain Highland Barley Pulp Prepared by a Novel Industry-Scale Microfluidizer System in Comparison with Colloid Milling.

The aim of this study was to assess the advantages of an industry-scale microfluidizer system (ISMS) to prepare whole-grain highland barley pulp (WHBP) compared with colloid milling. Storage stability was evaluated by particle size, gravity separation stability, and rheological properties, as well as the microstructure observation by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLMS). The results showed that colloid milling failed to effectively homogenize the material, while ISMS sample surfaces were compact and smooth at higher pressures according to visual observation and SEM. The Turbiscan stability index of WHBP by ISMS was much lower as a result of colloid milling, demonstrating ISMS can improve WHBP stability. WHBP by colloid milling displayed a three-peak particle size distribution pattern, while a single-peak pattern was evident after ISMS treatment. A higher shear rate decreased the apparent viscosity, suggesting that WHBP was a shear-thinning fluid. According to CLMS, ISMS can successfully improve homogenization by disrupting the structures of oil bodies, proteins, and starches. The WHBP prepared by ISMS exhibited a higher β-glucan level than that prepared by colloid milling, and showed a significant increase in β-glucan level with ISMS pressure. These findings indicate that using ISMS to produce WHBP is viable for enhancing its storage stability and nutritional value.

Alteration of β-glucan in the emerging fungal pathogen Candida auris leads to immune evasion and increased virulence

Candida auris is an emerging pathogenic yeast that has been categorized as a global public health threat and a critical priority among fungal pathogens. Despite this, the immune response against C. auris infection is still not well understood. Hosts fight Candida infections through the immune system that recognizes pathogen-associated molecular patterns such as β-glucan, mannan, and chitin on the fungal cell wall. In this study, levels of β-glucan and mannan exposures in C. auris grown under different physiologically relevant stimuli were quantified by flow cytometry-based analysis. Lactate, hypoxia, and sublethal concentration of fluconazole trigger a decrease in surface β-glucan while low pH triggers an increase in β-glucan. There is no inverse pattern between exposure levels of β-glucan and mannan in the cell wall architecture among the three clades. To determine the effect of cell wall remodeling on the immune response, a phagocytosis assay was performed, followed by quantification of released cytokines by ELISA. Lactate-induced decrease in β-glucan leads to reduced uptake of C. auris by PMA-differentiated THP-1 and RAW 264.7 macrophages. Furthermore, reduced production of CCL3/MIP-1⍺ but not TNF-⍺ and IL-10 were observed. An in vivo infection analysis using silkworms reveals that a reduction in β-glucan triggers an increase in the virulence of C. auris. This study demonstrates that β-glucan alteration occurs in C. auris and serves as an escape mechanism from immune cells leading to increased virulence.

A chemically induced attenuated strain of Candida albicans generates robust protective immune responses and prevents systemic candidiasis development.

Despite current antifungal therapy, invasive candidiasis causes >40% mortality in immunocompromised individuals. Therefore, developing an antifungal vaccine is a priority. Here, we could for the first time successfully attenuate the virulence of Candida albicans by treating it with a fungistatic dosage of EDTA and demonstrate it to be a potential live whole cell vaccine by using murine models of systemic candidiasis. EDTA inhibited the growth and biofilm formation of C. albicans. RNA-seq analyses of EDTA-treated cells (CAET) revealed that genes mostly involved in metal homeostasis and ribosome biogenesis were up- and down-regulated, respectively. Consequently, a bulky cell wall with elevated levels of mannan and β-glucan, and reduced levels of total monosomes and polysomes were observed. CAET was eliminated faster than the untreated strain (Ca) as found by differential fungal burden in the vital organs of the mice. Higher monocytes, granulocytes, and platelet counts were detected in Ca- vs CAET-challenged mice. While hyper-inflammation and immunosuppression caused the killing of Ca-challenged mice, a critical balance of pro- and anti-inflammatory cytokines-mediated immune responses are the likely reasons for the protective immunity in CAET-infected mice.

A chemically induced attenuated strain of Candida albicans generates robust protective immune responses and prevents systemic candidiasis development

Despite current antifungal therapy, invasive candidiasis causes >40% mortality in immunocompromised individuals. Therefore, developing an antifungal vaccine is a priority. Here, we could for the first time successfully attenuate the virulence of Candida albicans by treating it with a fungistatic dosage of EDTA and demonstrate it to be a potential live whole cell vaccine by using murine models of systemic candidiasis. EDTA inhibited the growth and biofilm formation of C. albicans. RNA-seq analyses of EDTA-treated cells (CAET) revealed that genes mostly involved in metal homeostasis and ribosome biogenesis were up- and down-regulated, respectively. Consequently, a bulky cell wall with elevated levels of mannan and β-glucan, and reduced levels of total monosomes and polysomes were observed. CAET was eliminated faster than the untreated strain (Ca) as found by differential fungal burden in the vital organs of the mice. Higher monocytes, granulocytes, and platelet counts were detected in Ca- vs CAET-challenged mice. While hyper-inflammation and immunosuppression caused the killing of Ca-challenged mice, a critical balance of pro- and anti-inflammatory cytokines-mediated immune responses are the likely reasons for the protective immunity in CAET-infected mice.

Structure-function relationship of oat flour fractions when blended with wheat flour: Instrumental and nutritional quality characterization of resulting breads.

The present work investigated the structure-function relationship of dry fractionated oat flour (DFOF) as a techno-functional ingredient using bread as a model system. Mechanically, DFOF fractions (F), that is, F1: <224µm, F2: 250-280µm, F3: 280-500µm, F4: 500-600µm, and whole oat flour (F5) were blended with white wheat flour at 10%, 30%, and 50% substitution levels for bread making. The blended flours, doughs, and bread samples were assessed for their techno-functional, nutritional, and structural characteristics. The results of Mixolab and the Rapid Visco Analyzer show that the 50% substituted F3 fraction exhibits the highest water absorption properties (69.53%), whereas the 50% F1 fraction exhibits the highest peak viscosity of the past slurry. Analysis of bread samples revealed a lower particle size of DFOF fractions and higher supplementation levels, increased β-glucan levels (0.13-1.29g/100 bread (db), reduced fermentable monosaccharides, that is, glucose (1.44-0.33g/100g), and fructose (1.06-0.28g/100g). The effect of particle size surpassed the substitution level effect on bread volume reduction. The lowest hardness value for F1 is 10%, and the highest value for F2 is 50%. The total number of cells in the bread slice decreased from the control to the F4 fraction (50%). Multi-criteria analysis indicated that DFOF fractions produced breads with similar structure and higher nutritional value developed from white wheat flour. PRACTICAL APPLICATION: The use of mechanically fractionated oat flours fractions in white wheat flour breads can improve the nutritional profile without affecting the physical properties of the bread product. Based on the oat flour fractions, bakers and food processing companies can tailor the bread formulations for high β-glucan, high fiber, and low reduced sugar claims.

Enhancing farmed striped catfish (Pangasianodon hypophthalmus) robustness through dietary β-glucan.

β-glucan is a well-documented feed additive for its potent immunostimulatory properties in many farmed fish species. This study examined how it can also be a promising growth promoter, modulate antioxidant enzyme activities, and act as an anti-stress agent in striped catfish (Pangasianodon hypophthalmus). A 12-week feeding experiment was untaken to determine the effects of dietary β-glucan supplementation at graded levels (0, 0.5, 1.0, and 1.5 g kg-1). Measured indicators suggest that a dietary inclusion level of 1.5 g kg-1 β-glucan gave the highest positive responses: weight gain (120.10 g fish-1), survival (98.30%), and lower FCR (1.70) (P<0.05). Whole body proximate analysis had only revealed that crude protein was significantly affected by the dietary inclusion of β-glucan (P<0.05), with the highest protein content (19.70%) being in fish that were fed with 1.5 g kg-1 β-glucan. Although other inclusion levels (i.e., 0.5 and 1 g kg-1) of β-glucan did not enhance body protein content (P>0.05). The assessment of fatty acid composition in muscle, liver, and adipose tissues showed modifications with the inclusion of β-glucan. Antioxidative-related enzyme activities (inc. catalase, glutathione peroxidase, and superoxide dismutase) that were measured in the liver had higher levels when fed with β-glucan inclusion diets (P<0.05). Following the feed trial, fish were subjected to crowding stress treatment. It was subsequently found that catfish fed with β-glucan-based diet groups had lower levels of blood stress-related indicators compared to the control group with no dietary β-glucan. The use of 1.5 g kg-1 of dietary β-glucan resulted in the lowest measured levels of cortisol (43.13 ng mL-1) and glucose (50.16 mg dL-1). This study has demonstrated that the dietary inclusion of β-glucan can have functional benefits beyond the immunological enhancements in striped catfish. Furthermore, its use can increase production levels and mitigate the stress associated with intensive farming practices.

Effects of the diet enrichment with β-glucan, sodium salt of butyric acid and vitamins on growth parameters and the profile of the gut microbiome of juvenile African catfish (Clarias gariepinus)

This study assessed the effect of the addition of active substances, i.e., β-glucan, sodium butyrate and vitamins (C, A, D3, E, K) to the diet of juvenile African catfish (Clarias gariepinus) on growth parameters and the intestinal microbiome. For this purpose, a four-week rearing of juveniles African catfish in a recirculating aquaculture system (RAS) under controlled conditions at 25°C was conducted. The fish were fed commercial feed (control group - C), which was enriched with various levels of sodium butyrate and β-glucan (FQV1 – FQV4). After the experiment, growth parameters such as weight gain (WG; g), length gain (LG; cm), specific growth rate (SGR; % d−1), condition factor (K) survival rate (SR; %) and cannibalism factor (CF; %) were determined. The profile of the intestinal microbiome was also determined using Next-Generation Sequencing (NGS) based on the analysis of the 16 S rRNA subunit. The obtained results indicated that feed supplementation with active substances in appropriate doses had a positive effect on the growth parameters of tested fish. Compared to the control group, statistically significant differences were obtained in WG (C - 7.62 g; FQV3 - FQV1 respectively 12.2–16.65 g), in WL (C - 6.23 cm; FQV3 - FQV1 respectively 7.59–8.74 cm), in SGR (C - 4.7%/d; FQV3 – V1 respectively 12.20 – 16.65 g), in K (C – 0.76; V3 – FQV4 respectively 0.80 – 0.84) (P <0.05). In addition, the control group had the highest value of CF (8.0%) compared to the research groups (P <0.05). The values of α-diversity metrics did not show statistically significant differences. However, the number of unique amplicon sequence variants (ASVs) in research groups confirmed that enriching the diet with the active substances increases the biodiversity of intestinal microbiome (C - 203; FQV4 - 373). In research groups and the control group, Firmicutes and Proteobacteria dominated, additionally, an increased number of beneficial lactic acid bacteria (LAB) of the Lactococcus and Bacillus genus was observed, while the number of potentially pathogenic bacteria of the Candidatus genus was reduced (P <0.05). Principal coordinate analysis (PCoA) determining β-diversity showed that the FQV3 was characterized by varied species composition compared to the other groups. The obtained results showed that a carefully selected composition of active ingredients used in the diet of juvenile African catfish has a beneficial effect on the profile and biodiversity of the intestinal microbiome, which indirectly improves resistance to infections and increases breeding indicators.

Partial replacement of saturated fats in liver pâté by an olive oil-in-water emulsion containing β-glucan shows no compromise in sensory and storage oxidation of lipids and protein.

The consumption of olive oil has been shown to have a positive effect on preventing obesity and hypertension. At the same time, it is recommended to avoid processed meat products as they contain saturated fats. The inclusion of highly unsaturated lipids in food products can lead to rapid oxidation and deterioration of sensory characteristics. The objective of the current work was to encapsulate olive oil and incorporate it into traditional Polish liver pâté. The oil-in-water emulsions were formulated with varying levels of oat β-glucan and were evaluated for droplet size, pH, encapsulation efficiency and rheology. The liver pâtés made using the emulsions with and without β-glucan were then evaluated for pH, texture, colour, lipid and protein oxidation, thermal stability and sensory properties. The results showed that the oil-in-water emulsions had a 100% encapsulation rate of olive oil after 30 days of storage at 4 °C, regardless of the presence of β-glucan. Although the texture of the emulsion-enriched liver pâté was different from that of the control, this difference was reduced when β-glucan was added to the emulsion and then to the pâté matrix. Replacing 50% of animal fat with an olive oil emulsion enriched with β-glucan did not result in any compromise of sensory properties, increase lipid or protein oxidation. These results suggest that it is possible to replace saturated lipids with omega-3-rich olive oil. © 2024 Society of Chemical Industry.

The Aspergillus fumigatus maiA gene contributes to cell wall homeostasis and fungal virulence.

In this study, two distinct in vitro infection models of Aspergillus fumigatus, using murine macrophages (RAW264.7) and human lung epithelial cells (A549), were employed to identify the genes important for fungal adaptation during infection. Transcriptomic analyses of co-incubated A. fumigatus uncovered 140 fungal genes up-regulated in common between both models that, when compared with a previously published in vivo transcriptomic study, allowed the identification of 13 genes consistently up-regulated in all three infection conditions. Among them, the maiA gene, responsible for a critical step in the L-phenylalanine degradation pathway, was identified. Disruption of maiA resulted in a mutant strain unable to complete the Phe degradation pathway, leading to an excessive production of pyomelanin when this amino acid served as the sole carbon source. Moreover, the disruption mutant exhibited noticeable cell wall abnormalities, with reduced levels of β-glucans within the cell wall but did not show lack of chitin or mannans. The maiA-1 mutant strain induced reduced inflammation in primary macrophages and displayed significantly lower virulence in a neutropenic mouse model of infection. This is the first study linking the A. fumigatus maiA gene to fungal cell wall homeostasis and virulence.

Quality Characteristics of Twelve Advanced Lines of Avena magna ssp. domestica Grown in Three Contrasting Locations in Morocco.

The popularity of oats (Avena sativa) continues to increase in the cereal market due to their health benefits. The recent domestication of Avena magna, a Moroccan oat, presents an opportunity to enhance these benefits due to their higher nutritional composition. As the impact of microclimates on A. magna grain composition has not been explored, this study evaluates twelve A. magna ssp. domestica lines across three Moroccan locations, providing new data into microclimate effects on key grain characteristics. Significant variability is observed among lines and sites for nutrients, with mean protein, fat, and dietary fiber contents at 23.1%, 8.38%, and 7.23%, respectively. High protein levels, reaching 27.1% in Alnif and 26.5% in El Kbab, surpass the 'Avery' control (21.7% and 24.2%) in these environments. Groats from Bouchane exhibited elevated fat and fiber contents (10.2% and 9.94%) compared to the control (8.83% and 7.36%). While β-glucan levels remain consistent at 2.53%, a negative correlation between protein content, fat, and starch was observed. A. magna lines exhibited higher levels of iron (7.50 × 10-3 g/100 g DM) and zinc (3.40 × 10-3 g/100 g DM) compared to other cereals. Environmental conditions significantly influence grain quality, with El Kbab yielding higher protein and ash contents, as well as Bouchane having increased fat, fiber, and starch. Stability analysis indicates that fat content was more influenced by the environment, while 25% of protein variability is influenced by genetics. Lines AT3, AT5, AT6, AT13, and AT15 consistently exceeds both the mean for protein and fiber across all sites, emphasizing their potential nutritional value. This study highlights the potential of A. magna ssp. domestica to address nutritional insecurity, particularly for protein, iron, and zinc in domestic settings.

Comprehensive Characterization of Global Barley (Hordeum vulgare L.) Collection Using Agronomic Traits, β-Glucan Level, Phenolic Content, and Antioxidant Activities.

This study characterized the diversity of 367 barley collections from 27 different countries, including 5 control cultivars, using several phenotypic traits. Morphological traits, including spike type, grain morphology, cold damage, and lodging rate, exhibited wide variations. Eighteen accessions matured early, while four accessions had longer culm and spike lengths than the controls. The ranges of total phenolic content (TPC), β-glucan content, ABTS•+ scavenging activity, DPPH• scavenging activity, and reducing power (RP) were 1.79-6.79 mg GAE/g, 0.14-8.41 g/100 g, 3.07-13.54 mg AAE/100 g, 1.56-6.24 mg AAE/g, and 1.31-7.86 mg AAE/g, respectively. Betaone, one of the controls, had the highest β-glucan content. Two accessions had β-glucan levels close to Betaone. Furthermore, 20 accessions exhibited increased TPC compared to the controls, while 5 accessions displayed elevated ABTS•+ scavenging activity. Among these, one accession also exhibited higher DPPH• scavenging activity and RP simultaneously. Based on the statistical analysis of variance, all the quantitative traits were significantly affected by the difference in origin (p < 0.05). On the other hand, grain morphology significantly affected biochemical traits. Multivariate analysis classified barley accessions into eight groups, demonstrating variations in quantitative traits. There were noteworthy correlations between biochemical and agronomical traits. Overall, this study characterized several barley varieties of different origins, anticipating future genomic research. The barley accessions with superior performances could be valuable alternatives in breeding.

Macromolecular characterization of high β-glucan oat lines

Oat (Avena sativa) is a cereal grain rich in fibers, proteins, vitamins and minerals. Oats have been linked to several health benefits, such as lowering blood cholesterol levels, counteracting cardiovascular disease and regulating blood sugar levels. This study aimed to characterize two new oat lines with high β-glucan content emanating from ethyl methyl sulphonate mutagenesis on the Lantmännen elite variety Belinda. Two of the mutated lines, and the mother variety Belinda, were profiled for β-glucan, arabinoxylan, total dietary fiber and starch composition. In addition, total lipid and protein content, amino acid composition and β-glucan molecular weights were analyzed. The high levels of β-glucan resulted in a significant increase in total dietary fiber, but no correlation could be established between higher or lower levels of the assayed macromolecules, i.e., between arabinoxylan-, starch-, lipid- or protein levels in the mutated lines compared to the reference. The results indicate separate biosynthetic pathways for β-glucans and other macromolecules and an independent regulation of the different polysaccharides studied. Therefore, ethyl methyl sulphonate mutagenesis can be used to increase levels of multiple macromolecules in the same line.

Characterization and nutritional valorization of agricultural waste corncobs from Italian maize landraces through the growth of medicinal mushrooms

The research investigates the potential use of maize cobs (or corncobs) from five genotypes, including the B73 inbred line and four locally cultivated landraces from Northern Italy, as substrate for implementing Solid State fermentation processes with four Medicinal Mushrooms (MMs). The corncobs were characterized based on their proximate composition, lignin, phenolics content (both free and bound), and total antioxidant capacity. Among the MMs tested, Pleurotus ostreatus and Ganoderma annularis demonstrated the most robust performance. Their growth was parametrized using Image Analysis technique, and chemical composition of culture samples was characterized compared to that of corncobs alone. In all culture samples, the growth of MMs led to a significant reduction (averaging 40%) in the total phenolics contents compared to that measured in corncobs alone. However, the high content of free phenolics in the cobs negatively impacted the growth of P. ostreatus. The final MM-corncob matrix exhibited reduced levels of free sugars and starch (≤ 2.2% DW, as a sum) and increased levels of proteins (up to 5.9% DW) and soluble dietary fiber (up to 5.0% DW), with a notable trend toward higher levels of β-glucan compared to corncobs alone. This research paves the way for the use of this matrix as an active ingredient to enhance the nutritional value of food preparations.

Impact of β-glucan dietary supplementation on productive, reproductive performance and physiological response of laying hens under heat stress conditions

The exploration for effective in-feed additives is growing owing to the global climatic change trend to alleviate the negative effects of heat stress in laying hens. This research assessed the potential of using B-glucan (G) as an antiheat stress agent in Matrouh laying hens subjected to early heat shock programs during the growing period. Factorial design (3 × 3) was used, including 3 levels of heat stress (control, heat shock at 3 d and at 3 d and 8 wk of age) and 3 levels of β-glucan (0, 100, and 200 mg β-glucan /kg diet). During the first 12 wk of egg production (EP), treatments were exposed to heat challenge. The results revealed that heat shock program applications at 3 d and 8 wk of age significantly decreased body weight at 36 wk of age (P < 0.05) and reduced (P < 0.05) feed intake (FI). While significantly (P < 0.05) improved feed conversion ratio (FCR), hemoglobin, RBCs, WBCs, immunoglobulin M (IgM), immunoglobulin G (IgG), and Heat shock protein (HSP70) of the Liver (P < 0.01) as compared with the control group. At the same time, there was a decrease in lymphocyte%, H/L ratio, cortisol, and T3 compared to the thermo-neutral control. When compared to the control group, hens fed a diet containing 200 mg of βG significantly (P < 0.05) improved body weight at 16 wk and final weight at 36 wk, feed conversion (FCR) (g. feed/g. egg mass), hen-day egg production, and egg mass, as well as the digestibility coefficients of crude protein (CP), dry matter (DM), metabolizable energy (ME), and cortisol. The interactions between heat chock programs and βG levels were nonsignificant for the most studied traits except daily feed intake. Therefore, the early heat shock exposure 2 times and supplementation of Β-glucan (βG) at 200 mg/kg diet during the growth period for laying hens that are exposed to heat stress during the reproductive period could improve productive, reproductive performance, HSP70 level and enhance immunity responses.

Dietary β-glucan ameliorates metabolic stress caused by a high dietary carbohydrate level in Nile tilapia

Carbohydrates are an excellent cost-friendly energy source for fish, and they have been used to improve growth performance and reduce dietary protein levels. However, the aquaculture industry has frequently overused high dietary carbohydrate levels, which has caused metabolic disturbances in fish. This deleterious effect is often diagnosed at the end of the production cycle, affects fish health and causes significant losses to farmers. In this context, β-glucan, which is broadly known as an immunomodulator, may ameliorate the deleterious effects caused by high levels of dietary carbohydrates. Therefore, we investigated the effect of dietary β-glucan on the reduction of metabolic disturbances in Nile tilapia fed a high carbohydrate diet. A total of 352 juvenile Nile tilapias (25.39 ± 0.83 g) were fed isoproteic (280 g kg−1 PD) and isoenergetic diets (3130 kcal kg−1) containing low amounts of carbohydrates (CHO-L 270 g kg−1) or high amounts of carbohydrates (CHO-H 620 g kg−1) with four levels of β-glucan (βG; 0, 1, 3 and 6 g kg−1) for 10 weeks. We evaluated the productive performance, plasma glucose, serum triglycerides, hepatosomatic index, total liver and muscle lipid, hepatic glycogen, hepatic activity of hexokinase, glucokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, malic enzyme, liver histopathology and innate immune responses. Fish fed a high carbohydrate diet had significantly increased productive performance and lipogenesis, presenting higher hepatosomatic indexes, triglycerides, hepatic glycogen, muscular lipid, hepatic activity of glucose-6-dehydrogenase phosphate, and malic enzyme. Additionally, histological analyses indicated expressive cytoplasm vacuolization. The innate immune responses such as leukocyte respiratory activity, complement and lysozyme were also significantly decreased for the high carbohydrate diet, indicating the occurrence of immunosuppression in fish. These results also indicate impaired metabolic functioning. However, β-glucan ameliorated metabolic stress. Specifically, we found a significant decrease in the serum levels of triglycerides, hepatosomatic index, muscular lipid, and hepatic activities of malic and glucose-6-dehydrogenase phosphate enzymes in fish fed high amounts of carbohydrates containing glucan. There was also a significant decrease in hepatic activity of the glycolytic pathway, hexokinase and pyruvate kinase. Moreover, β-glucan modulated the respiratory activity of leukocytes and complement, confirming its immunomodulating effect on fish. In conclusion, β-glucan mitigated the metabolic disturbances caused by the high levels of carbohydrates in the diet of Nile tilapia. This finding indicates that besides having an immunomodulating effect, β-glucan also has metabolic functions/benefits such as reducing glycolysis and lipogenesis.

Expression of genes encoding non-specific immunity, anti-oxidative status and aquaporins in β-glucan-fed golden mahseer (Tor putitora) juveniles under ammonia stress

The study investigated the effects of dietary administration of β-glucan on aquaporins and antioxidative & immune gene expression in endangered golden mahseer, Tor putitora juveniles, exposed to ammonia stress. For that, fish were fed experimental diets having 0 (control/basal), 0.25, 0.5, and 0.75% β-d-glucan for five weeks and then exposed to ammonia (10 mgL−1 total ammonia nitrogen) for 96 h. Administration of β-glucan differentially influenced the mRNA expression of aquaporins, anti-oxidative, and immune genes in ammonia-exposed fish. For instance, the transcript abundance of catalase and glutathione-s-transferase in gill varied significantly among the treatment groups, with the lowest levels in 0.75% β-glucan fed groups. At the same time, their hepatic mRNA expression was similar. Congruently, transcript abundance of inducible nitric oxide synthase considerably decreased in the β-glucan fed ammonia-challenged fish. Conversely, the relative mRNA expression of various immune genes viz., major histocompatibility complex, immunoglobulin light chain, interleukin 1-beta, toll-like receptors (tlr4 and tlr5) and complement component 3 remained largely unchanged in ammonia-exposed mahseer juveniles that were fed with graded levels of β-glucan. On the other hand, a significantly lower transcript level of aquaporins 1a and 3a was noticed in the gill of glucan-fed fish compared to ammonia-exposed fish that received the basal diet. However, branchial aquaporin 3b remained unaltered. Altogether, this study showed that dietary intake of 0.75% β-glucan improved resistance to ammonia stress to a certain degree, probably through activating anti-oxidative system and reducing brachial ammonia uptake.

Effects of milling behavior on the distribution of nutrients and storage properties of highland barley graded powder

Effects of gradual milling on the distribution of nutrients, bioactive components, and storage properties of highland barley graded powder (HBP) were investigated in this study. The results suggested that the contents of protein, crude fiber, total phenolics, total flavonoids, and γ-aminobutyric acid were the highest in the outermost layer (F-1), which were 16.01 ± 0.54 g/100 g, 9.18 ± 0.12 g/100 g, 717.34 ± 10.86 mg GAE/100 g, 209.68 ± 2.49 mg QE/100 g, 1.10 ± 0.03 mg/g DW, respectively. Conversely, the innermost layer (F-5) displayed the greatest β-glucan level with a value of 8.40 ± 0.18 g/100 g DW, which was 4.3 times of the amount of F-1. Additionally, the samples were subject to the heat-moisture steam treatment for 30 min (HM-30) and enjoyed optimal storage suitability. Consequently, the enzyme activity and free fatty acid value of the external fraction (mixture) and the removed-bran fraction (remainder) under HM-30 fell far below those of the control group. The remainder fraction presented a more stable storage ability as compared to the mixture fraction. Overall, these findings would gain a better insight into the comprehensive effect of milling on HBP and provide possible opportunities for building tailored-health highland barley in versatile foods.