Attenuation of inflammatory bowel disease by oral administration of mucoadhesive polydopamine-coated yeast β-glucan via ROS scavenging and gut microbiota regulation

Treatment for inflammatory bowel disease (IBD) is challenging since current anti-inflammatory and immunosuppressive therapies do not address the underlying causes of the illness, which include increased levels of reactive oxygen species (ROS) and dysbiosis of the gut commensal microbiota. Additionally, these treatments often have systemic off-target effects and adverse side effects. In this study, we have developed a prebiotic yeast β-glucan nanocomplex coated with bio-adhesive polydopamine (YBNs@PDA) to effectively prolong their retention time in the gastrointestinal (GI) tract. The oral administration of YBNs@PDA restored the epithelium barriers, reduced ROS levels, and minimized systemic drug exposure while improved therapeutic efficacy in an acute colitis mouse model. Furthermore, 16S ribosomal RNA genes sequencing demonstrated a higher richness and diversity in gut microflora composition following the treatments. In particular, YBNs@PDA markedly augmented the abundance of Lachnospiraceae NK4A136 and Bifidobacterium, both of which are probiotics with crucial roles in relieving colitis via retaining gut homeostasis. Cumulatively, these results demonstrate that the potential of YBNs@PDA as a novel drug-free, ROS-scavenging and gut microbiota regulation nanoplatform for the treatment of GI disorders.

Hyaluronic acid-modified yeast β-glucan particles delivering doxorubicin for treatment of breast cancer

Breast cancer is one of the most threatening cancers that poses a great risk to women's health. The anti-tumor drug doxorubicin (DOX) is one of commonly used drugs in the treatment of breast cancer. However, the cytotoxicity of DOX has always been an urgent challenge to be solved. In this study, we report an alternative drug delivery system delivering DOX for reducing its physiological toxicity by using the yeast β-glucan particle (YGP) with a hollow and porous vesicle structure. Briefly, amino groups were grafted onto the surface of YGP with the silane coupling agent, then the oxidized hyaluronic acid (OHA) was attached by Schiff base reaction to get HA-modified YGP (YGP@N=C-HA), finally DOX was encapsulated into YGP@N=C-HA to get DOX-loaded YGP@N=C-HA (YGP@N=C-HA/DOX). In vitro release experiments exhibited the pH-responsive DOX release from YGP@N=C-HA/DOX. Cell experiments displayed that YGP@N=C-HA/DOX had good killing effect on both MCF-7 and 4T1 cells and could be internalized into these cells through CD44 receptors, showing targetability to cancer cells. Furthermore, YGP@N=C-HA/DOX could effectively inhibit tumor growth and reduce the physiological toxicity of DOX. Thus, the YGP-based vesicle provides an alternative strategy for lowering the physiological toxicity of DOX in the medical treatment of breast cancer.

A wet-adhesive carboxymethylated yeast β-glucan sponge with radical scavenging, bacteriostasis and anti-inflammatory functions for rapid hemostasis

Local hemostats still face obstacles to efficiently achieving hemostasis and promoting wound healing. Herein, a series of multifunctional well-degradable hemostatic sponges based-on carboxymethylated yeast β-glucan (CMYG) were fabricated by lyophilization. The porous CMYG sponge not only could absorb blood quickly (44.12 g/g), but also possessed unexpected tissue adhesion (∼30 kPa), and it represented good biocompatibility in vitro on fibroblasts and red blood cells. Notably, compared with the commercial Celox™, the CMYG sponge achieved more rapid hemostasis and significantly reduced blood loss in liver injury rat models by rapid wound block. Interestingly, the developed sponge showed an outstanding effect on antioxidant, anti-infection, anti-inflammatory, and cell proliferation, which are beneficial for further wound repair. Overall, these results suggest that the CMYG sponge is a promising candidate for the clinical management of uncontrollable hemorrhage and the further development of wound dressing materials throughout skin defect repair.

Effects of ultrasound-assisted H2O2 on the solubilization and antioxidant activity of yeast β-glucan

Yeast β-glucan (YG) possess an extensive range of biological activities, such as the inhibition of oxidation, but the poor water solubility of macromolecular YG limits its application. In this study, through the combined degradation of ultrasonic waves and H₂O₂, and the optimization of the main process parameters for solubilizing YG by response surface methodology (RSM), a new product of YG_UH was generated. The molecular weight, structural characteristics and degradation kinetics before and after solubilization were evaluated. The results showed that the optimal solubilization conditions were reaction time: 4 h, ultrasonic power: 3 W/mL, H₂O₂ concentration: 24 %. Under these conditions, ultrasound-assisted H₂O₂ increased the solubility (from 13.60 % to 70.00 %) and reduced molecular weight (from 6.73 × 10⁶ Da to 1.22 × 10⁶ Da). Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), Congo red (CR), scanning electron microscopy (SEM) revealed that ultrasound-assisted H₂O₂ increased the conformation's flexibility greatly, without changing the main structure of YG. More importantly, solubilization of YG improved free radical scavenging activity with YG_UH exhibiting the highest levels of DPPH and ABTS⁺ free radical scavenging activity. These results revealed that ultrasound-assisted H₂O₂ degradation could be a suitable way to increase the solubility of YG for producing value-added YG.

Improvement of the gel properties and flavor adsorption capacity of fish myosin upon yeast β-glucan incorporation

The potential effects of yeast β-glucan (YG) on heat-induced gel properties, microstructure and flavor adsorption capacity of fish myosin at different NaCl concentrations were investigated in this study. The incorporation of YG significantly improved the texture properties, gel strength, water holding capacity (WHC), storage modulus and loss modulus of myosin gels, especially at a high salt level, whereas the whiteness declined. Furthermore, myosin gels containing YG displayed a more compact and ordered three-dimensional network structure, accompanied by the increasing immobilization of water in gels. The binding abilities of gels to selected flavor compounds at high salt content were inferior to those at the low salt content. Regardless of the salt level, YG addition boosted the flavor binding capacity of gels, which might be attributed to the unfolding of the protein conformation by exposing more flavor-binding sites, as well as the porous sponge structure of YG with unique adsorption capacity.

Ultrasound-assisted enzymatic hydrolysis of yeast β-glucan catalyzed by β-glucanase: Chemical and microstructural analysis

The purpose of this study was to investigate the effect of ultrasound-assisted enzymolysis on modified solubilization of yeast β-glucan and its related mechanism. The depolymerization effects of this system on the physicochemical properties and structural features of the degraded fragments were studied systematically. The structure and physicochemical properties of the samples showed that the solubility of yeast β-glucan achieved 75.35 % after modification; and ultrasonic enzymatic enhanced the degradation efficiency. The yeast β-glucan obtained after solubilization and modification owned better antioxidant activities. The yeast β-glucan particles become obviously smaller, sparsely dispersed in the aqueous solution and the stability was improved. In addition, the hydrogen bonds in yeast β-glucan native triple helix structure were partially broken. Moreover, the disruption of yeast β-glucan's original structure made it decreased thermostability and easier to dissolve in water. The atomic force microscope (AFM) imaging directly verified the branched-chain morphology of yeast β-glucan and the small-strand degradation fragments. Therefore, this research can provide a feasible and effective approach for improving solubility of water-insoluble yeast β-glucan to enlarge its food and biomedical applications.

Effects of yeast β-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis

PURPOSE

Yeast β-glucans are known for their immune-modulating effects; however, their effects on human upper respiratory tract infections (URTIs) remain unclear. The aim of the present study was to use a systematic review and meta-analysis approach to investigate the effects of yeast β-glucans for the prevention and treatment of URTIs in healthy subjects.

METHODS

Databases including Pubmed, Web of Science, EMBASE and the Cochrane Library were searched and 13 RCTs investigating the effects of yeast β-glucans on the incidence, duration, and severity of URTIs in healthy subjects were included.

RESULTS

The results showed that compared to the placebo group, yeast β-glucan could significantly reduce the incidence of URTIs (OR = 0.345, 95% CI = 0.192 to 0.620, p < 0.001), decrease the average number of URTI episodes (SMD =  - 0.315, 95% CI =  - 0.500 to  - 0.130, p < 0.05), and decrease the duration of URTIs (SMD =  - 0.312, 95% CI =  - 0.561 to  - 0.064, p < 0.001). Improved severity of symptoms was found in yeast β-glucan group compared to the placebo group in the majority of included studies. In addition, yeast β-glucan was well tolerated and safe in general.

CONCLUSION

These findings suggest a positive effect of yeast β-glucans on human URTIs. However, due to the high heterogeneity and small number of included studies, more high-quality research and clinical trials are warranted.

Quantification of 1,3-β-D-glucan from yeast added as a functional ingredient to bread

Due to their immunomodulatory effect, 1,3-β-G from yeast are used as functional ingredients, but reliable methods for their detection in foods are lacking. We have adapted a method based on fluorescence detection with aniline blue to quantify the amount of five commercial yeast β-glucan preparations added to crisp or yeast-leavened bread. This assay detected yeast β-glucan preparations added to different breads with an average recovery of 90, 96, 99 and 105%, while one of the preparations was overestimated, with an average recovery of 157%. The presence of cereal 1,3-1,4-β-_D-glucans did not interfere with assay performance. The addition of 1,3-β-G at 0.2 and 0.5 g/100g is low compared to the recommended dose of 1,3-β-G per serving demonstrating assay sensitivity. However, more research is needed to fully understand the effect of 1,3-β-G conformation/structure on aniline blue interaction as well as the effect of baking on structure and dissolution properties of yeast β-glucans.

The linear structure of β-glucan from baker's yeast and its activation of macrophage-like RAW264.7 cells

Yeast β-glucan has many formulations with different chemical structures, water solubility and purity. In particular, the purity of β-glucan in these formulations is variable and relatively low, contributing to different data on its biological activity. In this study, the major polysaccharide component in the crude Baker's yeast polysaccharides coded as BBG with high purity of 99% was obtained, and its chemical structure was determined to be a linear β-(1,3)-glucan. It was found that BBG interacted with complement receptor 3 (CR3) and toll-like receptor 2 (TLR2) on the surface of macrophage-like RAW264.7 cells, and initiated activation of RAW264.7 cells characterized by significant production of tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Additionally, activation of the nuclear factor kappaB p65 (NF-κB p65), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) induced by BBG, were also observed, further confirming the stimulation of RAW264.7 cells by BBG. All these findings provided important scientific evidences for better understanding the molecular mechanism of action for the linear β-(1,3)-glucan in cells.