β-Glucan improves wound healing in silver catfish (Rhamdia quelen)

Addition of β-glucans in diets for tropical gar (Atractosteus tropicus) larvae: effects on growth, digestive enzymes and gene expression of intestinal epithelial integrity and immune system

The effect of β-glucans 1,3/1,6 from Saccharomyces cerevisiae yeast at different inclusion percentages (0.0, 0.2, 0.4, 0.6, and 0.8%) in the diet for tropical gar (Atractosteus tropicus) larvae was evaluated on growth, digestive enzyme activity and, relative expression of the immune system genes. The bioassay started on the third day after hatching (DAH) and lasted 21 days, using a total of 1500 larvae of 0.055 ± 0.008 g and, a total length of 2.46 ± 0.26 cm. Larviculture was carried out in a recirculation system with 15 tanks of 70 L using a density of 100 organisms per experimental unit. No significant differences in larval growth were observed by the inclusion of β-glucans (p > 0.05). Digestive enzymes showed changes in lipase and trypsin activities, presenting higher values in fish fed 0.6% and 0.8% β-glucans diets compared to the other treatments (p < 0.05). Leucine-aminopeptidase, chymotrypsin, acid phosphatase, and alkaline phosphatase activity showed higher activities in larvae fed with a 0.4% β-glucan diet compared to the control group. The relative expression of intestinal membrane integrity (mucin 2) muc-2, (occludins) occ, (nucleotide-binding oligomerization domain) nod-2, and immune system lys (lysosome) genes showed over-expression in larvae fed the 0.4% β-glucan diet to the rest of the treatments (p < 0.05). The inclusion of β-glucans at 0.4-0.6% in diets for A. tropicus larvae could improve larviculture, as effects on the increase in the activity of several digestive enzymes and the expression of genes of the immune system.

Dietary supplementation of β-1, 3-glucan improves the intestinal health of white shrimp (Litopenaeus vannamei) by modulating intestinal microbiota and inhibiting inflammatory response

The phenomenon of intestinal dysfunction is widely observed in white shrimp (Litopenaeus vannamei) culture, and β-1,3-glucan has been confirmed to be beneficial in intestinal health with a lack understanding of its underlying mechanism. Proteobacteria, Firmicutes, and Actinobacteria served as the predominant phyla inhabiting the intestine of white shrimp, whilst a significant variation in their proportion was recorded in shrimp fed with basal and β-1,3-glucan supplementation diets in this study. Dietary supplementation of β-1,3-glucan could dramatically increase the microbial diversity and affect microbial composition, concurrent with a notable reduction in the ratio of opportunistic pathogen Aeromonas, gram-negative microbes, from Gammaproteobacteria compared to the basal diet group. The benefits for microbial diversity and composition by β-1,3-glucan improved the homeostasis of intestinal microbiota through the increase of specialists' number and inhibition of microbial competition caused by Aeromonas in ecological networks; afterward, the inhibition of Aeromonas by β-1,3-glucan diet dramatically suppressed microbial metabolism related to lipopolysaccharide biosynthesis, followed by a conspicuous decrease in the intestinal inflammatory response. The improvement of intestinal health referred to the elevation in intestinal immune and antioxidant capacity, ultimately contributing to the growth of shrimp fed β-1,3-glucan. These results suggested that β-1,3-glucan supplementation improved the intestinal health of white shrimp through the modulation of intestinal microbiota homeostasis, the suppression of intestinal inflammatory response, and the elevation of immune and antioxidant capacity, and subsequently promoted the growth of white shrimp.

Application of Tissue Engineering in Manufacturing Absorbable Membranes to Improve the Osteopromoting Potential of Collagen

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm³) in the BG, followed by the CB (11.850 mm³), and CP (9.560 mm³) group. The collagen membranes associated with HA demonstrated an osteopromotive potential.

An important polysaccharide from fermentum

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Extraction, structure and modification of polysaccharides from fermentum were summarized.

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Structure-activity relationship and application of polysaccharides from fermentum were reviewed.

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It provided a strong basis for the development and application of polysaccharides from fermentum.

Fermentum is a common unicellular fungus with many biological activities attributed to β-polysaccharides. Different in vivo and in vivo experimental studies have long proven that fermentum β-polysaccharides have antioxidant, anti-tumor, and fungal toxin adsorption properties. However, there are many uncertainties regarding the relationship between the structure and biological activity of fermentum β-polysaccharides, and a systematic summary of fermentum β-polysaccharides is still lacking. Herein, we reviewed the research progress about the extraction, structure and modification, structure–activity relationship, activity and application of fermentum β-polysaccharides, compared the extraction methods of fermentum β-polysaccharide, and paid special attention to the structure–activity relationship and application of fermentum β-polysaccharide, which provided a strong basis for the development and application of fermentum β-polysaccharide.

Yeast β-Glucans as Fish Immunomodulators: A Review

Simple Summary

The β-glucan obtained from yeast—a very important molecule for fish production—activates the immune system of fish by different mechanisms and induces protection against pathogens. However, most previous related studies have focused on the use of commercial β-glucan from the yeast Saccharomyces cerevisiae to understand the activation pathways. Experimental β-glucans extracted from other yeasts show other interesting biological activities even at lower doses. This review article analyzes the current information and suggests perspectives on yeast β-glucans.

Abstract

Administration of immunostimulants in fish is a preventive method to combat infections. A wide variety of these biological molecules exist, among which one of the yeast wall compounds stands out for its different biological activities. The β-glucan that forms the structural part of yeast is capable of generating immune activity in fish by cell receptor recognition. The most frequently used β-glucans for the study of mechanisms of action are those of commercial origin, with doses recommended by the manufacturer. Nevertheless, their immune activity is inefficient in some fish species, and increasing the dose may show adverse effects, including immunosuppression. Conversely, experimental β-glucans from other yeast species show different activities, such as antibacterial, antioxidant, healing, and stress tolerance properties. Therefore, this review analyses the most recent scientific reports on the use of yeast β-glucans in freshwater and marine fish.

High-cell-density cultivation of the flagellate alga Poterioochromonas malhamensis for biomanufacturing the water-soluble β-1,3-glucan with multiple biological activities

The microalga Poterioochromonas malhamensis was found to be capable of accumulating the storage β-1,3-glucan in soluble form under heterotrophic conditions. In this study, the highest biomass yield of 32.8 g L^-1 was achieved by combining the utilization of ammonium chloride as the nitrogen source, simultaneous addition of vitamins B1 and B12 and maintenance of pH at 6.0. Sugar profiling and nuclear magnetic resonance analysis indicated that the P. malhamensis β-1,3-glucan was composed of glucose with the β-(1 → 3) main chain and the β-(1 → 6) side chain. Under the optimal cultivation conditions, the cellular β-1,3-glucan content was up to 55% of the cell dry weight. Moreover, the P. malhamensis β-1,3-glucan could significantly promote the fin regeneration and improve the in vivo antioxidative activity of zebrafish. This study underpins the feasibility of culturing P. malhamensis under heterotrophic conditions for producing the highly water-soluble bioactive β-1,3-glucans for food and pharmaceutical applications.

USE OF TOPICAL TREATMENTS AND EFFECTS OF WATER TEMPERATURE ON WOUND HEALING IN COMMON CARP (CYPRINUS CARPIO)

Skin lesions are frequently diagnosed in fish medicine. Although systemic fish treatments exist, little is known about the efficacy of topical drugs on fish skin lesions. This study aimed to investigate the efficacy of medical-grade honey and silver sulfadiazine on skin lesions using common carp (Cyprinus carpio) as a model. Additionally, the effect of temperature on the wound healing process was evaluated. Punch biopsies were generated on six fish per treatment group under anesthesia. Treatment groups received one of the following topical medications after wounding: Dr. Nordyke's Wound Honey, MicroLyte Ag Vet, or SilvaSorb Gel. Nontreated positive control groups were similarly wounded but did not receive topical treatment. Fish were housed at 10°C to 13°C or 18°C to 21°C for 29 days. Macroscopic evaluation and image collection of wounds were performed on days 0, 4, 8, 12, 21, and 29 after wounding to compare changes in wound areas and inflammation over time. On day 29, tissue samples were collected for histologic analysis. From day 12 after wounding onward, wounds in positive controls maintained at 18°C to 21°C were significantly smaller (days 12, 21, and 29: P < 0.0001) compared with positive controls kept at 10°C to 13°C. There was an overall improvement in macroscopic appearance in honey-treated groups compared with positive controls on day 12 after wounding at 18°C to 21°C (P = 0.001), whereas with the use of Microlyte and Silvasorb, wounds had increased inflammation grades (P < 0.0001 and P < 0.0001, respectively) with enlarged wound areas (P < 0.0001 and P < 0.001, respectively) in comparison with positive controls on day 12 after wounding at 18°C to 21°C. This study suggests that topical use of medical-grade honey produces positive effects on wound healing in the carp model and higher water temperatures enhance the effects, whereas the use of silver sulfadiazine and lower water temperatures delays or worsens the wound healing process.

Modulation of growth performance, gut microflora, non-specific immunity and gene expression of proinflammatory cytokines in shabout (Tor grypus) upon dietary prebiotic supplementation

In this study, the effect of dietary supplementation of mannan oligosaccharide (MOS) + β-glucan (Immunogen®) was investigated on growth performance, body composition, gut microflora, innate immune responses and gene expression of some proinflammatory cytokines in shabout (Tor grypus). Shabout fingerlings (35 ± 1.2 g) were fed with basal diet (control) or basal diet supplemented with Immunogen® at 0.5, 1 and 1.5% of feed for 90 days. According to the results, growth parameters were significantly improved in fish fed with prebiotic (1 and 1.5%) for 90 days (p < 0.05). The carcass protein content was significantly higher in fish nourished by prebiotic at 1.5% of feed for 90 days compared to fish received the basal diet (p < 0.05). Feeding with various levels of Immunogen® resulted in the significant promotion of the population of intestinal Lactobacillus spp. in the prebiotic-treated groups relative to the control group (p < 0.05). Serum total globulin was significantly higher in all prebiotic groups relative to the control group at day 60. Serum bactericidal and lysozyme activities were significantly (p < 0.05) elevated after feeding with dietary prebiotic at all intervals (days 30, 60 and 90). However, the highest serum bactericidal activities were recorded in fish fed with Immunogen® at 1.5% of diet (p < 0.05). The transcription levels of interleukin 1 beta (IL-1β), interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) were significantly increased in the head kidney of fish treated with dietary prebiotic at all intervals. The results show that dietary supplementation with Immunogen®, particularly at the level of 1.5%, can positively alter growth parameters, carcass protein, intestinal microflora and immune responses of shabout.

Spirulina maxima derived marine pectin promotes the in vitro and in vivo regeneration and wound healing in zebrafish

Purified bioactive components of marine algae have shown great pharmaceutical and biomedical potential, including wound healing activity. However, the activity of Spirulina maxima is the least documented with regard to wound healing potential. In the present study, we investigated the regenerative and wound healing activities of a Spirulina (Arthrospira) maxima based pectin (SmP) using in vitro human dermal fibroblasts (HDFs) and in vivo zebrafish model. SmP treated (12.5-50 μg/mL) HDFs showed increased cell proliferation by 20-40% compared to the untreated HDFs. Moreover, in vitro wound healing results in HDFs demonstrated that SmP decreased the open wound area % in concentration-dependent manner at 12.5 (32%) and 25 μg/mL (12%) compared to the control (44%). Further, zebrafish larvae displayed a greater fin regenerated area in the SmP exposed group at 25 (0.48 mm²) and 50 μg/mL (0.51 mm²), whereas the untreated group had the lowest regenerated area (0.40 mm²) at 3 days post amputation. However, fin regeneration was significantly (P < 0.001) higher only in the SmP treated group at 50 μg/mL. Furthermore, the open skin wound healing % in adult zebrafish was significantly higher (P < 0.05) after topical application (600 μg/fish) of SmP (46%) compared to the control (38%). Upregulation of genes such as tgfβ1, timp2b, mmp9, tnf-α, and il-1β, and chemokines such as cxcl18b, ccl34a.4, and ccl34b.4, in the muscle and kidney tissues of SmP treated fish compared to the respective control group was demonstrated using qRT-PCR. Histological analysis results further supported the rapid epidermal growth and tissue remodeling in SmP treated fish, suggesting that SmP exerts positive effects associated with wound healing. Therefore, SmP can be considered a potential regenerative and wound healing agent.

Development of Fish Immunity and the Role of β-Glucan in Immune Responses

Administration of β-glucans through various routes, including immersion, dietary inclusion, or injection, have been found to stimulate various facets of immune responses, such as resistance to infections and resistance to environmental stress. β-Glucans used as an immunomodulatory food supplement have been found beneficial in eliciting immunity in commercial aquaculture. Despite extensive research involving more than 3000 published studies, knowledge of the receptors involved in recognition of β-glucans, their downstream signaling, and overall mechanisms of action is still lacking. The aim of this review is to summarize and discuss what is currently known about of the use of β-glucans in fish.

The protective role of spirulina and β-glucan in African catfish (Clarias gariepinus) against chronic toxicity of chlorpyrifos: hemato-biochemistry, histopathology, and oxidative stress traits

Chlorpyrifos (CPF) is an insecticide that is commonly applied in the agriculture sector. However, little is known about the protective role of Spirulina platensis (SP) and/or β-glucan (BG) on African catfish exposed to chronic CPF toxicity. The fish (95 ± 5 g, initial weight) were assigned to 5 fiberglass tanks (500 L, 50 fish/tank) where the 1st and 2nd fed the basal diet, while the 3rd, 4th, and 5th fed diets with SP, BG, and SP+BG at 0.5%, respectively. Fish in 2nd, 3rd, 4th, and 5th groups were exposed to CPF at a dose of 1.5 mg/L and fed the respective diets for 60 days. In comparison with the control group, CPF-exposed fish exhibited significantly lower (P ≤ 0.05) body weights, feed intake, red blood cells count, hemoglobin concentration, packed cell volume (PCV) (%), lymphocytes, monocytes, phagocytic activity, and phagocytic index, while feed conversion ratio, white blood cell count, and neutrophils count were significantly increased. Fish exposed to CPF also revealed a significant elevation in aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, triglycerides, low-density lipoproteins (LDL), very-low-density lipoproteins (vLDL), glucose concentration, urea, and creatinine as well as low total proteins, albumin, globulins, and high-density lipoprotein (HDL) concentration. Fish exposed to CPF also exhibited a high concentration of malondialdehyde while glutathione content, glutathione peroxidase, and catalase activities were significantly decreased in the liver, gills, brain, and intestine tissues. Moreover, exposure to CPF resulted in higher transcription of cytochrome P450 (CYP1A-P450) gene expression than the 1st group. Histopathological investigations revealed various degrees of pathological lesions in different organs like the liver, kidney, brain, spleen, and intestine tissues. Interestingly, dietary SP supplementation either alone or combined with BG significantly ameliorated the alterations mitigated by CPF-induced organ injuries and genotoxicity. Therefore, it could be concluded that SP or/and BG are able to induce the protective consequences on health status, immunity, and antioxidative response of African catfish exposed to CPF.