Gastroprotective effects of polysaccharides from purple sweet potato (Ipomoea batatas (L.) Lam) on an ethanol-induced gastric ulcer via regulating immunity and activating the PI3K/Akt/Rheb/mTOR pathway.

The study aimed to investigate the alleviation of an ethanol-induced gastric ulcer in mice by apolysaccharide (PSP) from purple sweet potato (Ipomoea batatas (L.) Lam) and explore the mechanism. The anti-ulcer activity was determined by histopathological evaluation, total gastric acidity, pepsin activity, gastric ulcer index and gastric ulcer inhibition rate. The expression levels of inflammatory factors were detected using ELISA. A special protein meter was used to detect the content of immunoglobulin lgM, immunoglobulin lgG, and complements C3 and C4 in the serum of mice. The expression of CD4+/CD8+ lymphocyte subsets of mice was detected using flow cytometry. Western blot analysis was used to examine the effect of PSP on the PI3K/Akt/Rheb/mTOR pathway. The results showed that PSP could effectively reduce the total gastric acidity, pepsin activity, and the index and inhibition rate of gastric ulcers. At the same time, PSP could significantly increase the levels of immunoglobulins (lgG and lgM) and complements (C3 and C4). It could also increase the activity of peritoneal macrophages in mice and the expression of CD4+/CD8+ in the spleen. ELISA analysis showed that the contents of TNF-α, IL-1ß and IL-6 were significantly decreased and the content of IL-10 was significantly increased in the PSP group. The western blot analysis showed that PSP could upregulate the relative protein expressions of MUC5AC, PI3K, p-Akt, Rheb and mTOR. These results indicate that PSP can activate the PI3K/Akt/Rheb/mTOR signaling pathway to improve the immunity of mice and maintain the balance of the immune system, thereby protecting the gastric mucosa and improving stress gastric ulcers.

ECMpy 2.0: A Python package for automated construction and analysis of enzyme-constrained models.

Genome-scale metabolic models (GEMs) have been widely employed to predict microorganism behaviors. However, GEMs only consider stoichiometric constraints, leading to a linear increase in simulated growth and product yields as substrate uptake rates rise. This divergence from experimental measurements prompted the creation of enzyme-constrained models (ecModels) for various species, successfully enhancing chemical production. Building upon studies that allocate macromolecule resources, we developed a Python-based workflow (ECMpy) that constructs an enzyme-constrained model. This involves directly imposing an enzyme amount constraint in GEM and accounting for protein subunit composition in reactions. However, this procedure demands manual collection of enzyme kinetic parameter information and subunit composition details, making it rather user-unfriendly. In this work, we've enhanced the ECMpy toolbox to version 2.0, broadening its scope to automatically generate ecGEMs for a wider array of organisms. ECMpy 2.0 automates the retrieval of enzyme kinetic parameters and employs machine learning for predicting these parameters, which significantly enhances parameter coverage. Additionally, ECMpy 2.0 introduces common analytical and visualization features for ecModels, rendering computational results more user accessible. Furthermore, ECMpy 2.0 seamlessly integrates three published algorithms that exploit ecModels to uncover potential targets for metabolic engineering. ECMpy 2.0 is available at https://github.com/tibbdc/ECMpy or as a pip package (https://pypi.org/project/ECMpy/).

Structure Characterization and Immunomodulatory Activity of Misgurnus anguillicaudatus Carbohydrates.

Misgurnus anguillicaudatus, also known as oriental weather loach, is widely consumed and favored in East Asia due to its superior nutritional values and excellent flavor. In this study, a crude Misgurnus anguillicaudatus carbohydrates (MAC) was isolated from Misgurnus anguillicaudatus. Subsequently, two parts, which were named MAO and MAP, respectively, were separated from MAC, and their primary structures and immunomodulatory activity were investigated. The results showed that MAO had a molecular weight of 2854 Da, and principally consisted of arabinose (77.11%) and rhamnose (21.97%), together with minor levels of fucose (0.92%); MAP, with a molecular weight of 3873 Da, was mainly composed of fucose (87.55%) and a small amount of rhamnose (8.86%) and galactose (3.59%). The in vitro assay showed that MAC could significantly enhance the proliferation of macrophages without cytotoxicity and increase the production of immune substances (TNF-α, IL-6). Together with Western blot results, we speculated that MAC could stimulate RAW264.7 murine macrophage cells to secrete TNF-α and IL-6 through up-regulating TLR4-MAPK-p38 signaling pathways. The results indicated that MAC could be a potential immune agent and might provide meaningful information for further chain conformation and immune mechanism research.

Structural Identification and Antioxidant Activity of Loach Protein Enzymatic Hydrolysates.

Loach, rich in nutrients, such as proteins, amino acids, and mineral elements, is being gradually favored by consumers. Therefore, in this study, the antioxidant activity and structural characteristics of loach peptides were comprehensively analyzed. The loach protein (LAP) with a molecular weight between 150 and 3000 Da was graded by ultrafiltration and nanofiltration processes, which exhibited excellent scavenging activity against DPPH radical (IC50 2.91 ± 0.02 mg/mL), hydroxyl radical (IC50 9.95 ± 0.03 mg/mL), and superoxide anion radical (IC50 13.67 ± 0.33 mg/mL). Additionally, LAP was purified by gel filtration chromatography, and two principal components (named as LAP-I and LAP-II) were isolated. A total of 582 and 672 peptides were identified in LAP-I and LAP-II, respectively, through structural analysis. The XRD results revealed that LAP-I and LAP-II had an irregular amorphous structure. The 2D-NMR spectroscopy results suggested that LAP-I had a compact stretch conformation in the D2O solution, while LAP-II had a folded conformation. Overall, the study results suggested that loach peptide could be a potential antioxidant agent and might provide valuable information for chain conformation and antioxidant mechanism research further.

Impact of garlic oligosaccharide fractions on microcosmic, mesoscopic, or macroscopic characteristics of dough.

Threeoligosaccharides, namely single clove garlic (SGOS), purple garlic (PGOS), and Cangshan hybrid garlic (HGOS), were prepared by water extraction and ethanol precipitation. The chemical composition and molecular weight of garlic oligosaccharides were elucidated by gas chromatograph, high-performance liquid chromatography,Fourier-transform infrared (FTIR), and nuclear magnetic resonance (NMR) analyses. Moreover, fortified dough was prepared by adding garlic oligosaccharides at different proportions to evaluate the interaction of the obtained oligosaccharides with gluten proteins. Additionally, the microcosmic, mesoscopic, and macroscopic characteristics of the fortified dough were investigated in terms of the physical and rheological properties, thermodynamic parameters, moisture distribution, morphology, and protein secondary structure using texture profile analysis, rheology, differential scanning calorimetry, low-field NMR, scanning electron microscopy, confocal laser scanning microscopy and FTIR analyses. The results indicated that SGOS was mainly composed of galactose. SGOS fraction had a slightly higher molecular weight (3.00 × 103 Da) compared to the HGOS and PGOS fractions (2.90 × 103 Da), which showed the most compatibility with the dough matrix, thereby improving the dough quality. The present study results can provide a theoretical basis for the application of garlic oligosaccharides in the development of flour-based products.

Structural characteristics and immunostimulatory activity of sea cucumber tendon polysaccharides in cyclophosphamide-induced Balb/c mice.

Sea cucumber tendon, one of the main parts of sea cucumber viscera, is widely accepted as a waste residue. In this study, a sea cucumber tendon polysaccharide (SCTPII) was purified from sea cucumber tendons and its primary structures and immunomodulatory activity were investigated. SCTPII is a triple-helix conformation homogeneous polysaccharide with a molecular weight of 3.97 × 106 Da that consists of glucose and fucose with molar ratios of 92.09% and 7.91% with high thermostability. In vivo tests on immunosuppressed Balb/c mice revealed that compared with the model group, the proliferation of T cells and B cells in splenic lymphocytes of mice in the high-dose group was significantly improved by 0.92 times and 5.14 times, respectively. Additionally, SCTPII could improve the proliferation ability and phagocytosis of macrophages, as well as promoting the expression of IL-6, TNF-α and IFN-γ and enhancing the intestinal physical barrier function by increasing the protein expression of claudin-1, occludin, ZO-1 and MUC2. Furthermore, the 16S rRNA sequencing of fecal samples was performed, and gene count and α-diversity analysis revealed that SCTPs could improve the microbial community richness. In particular, SCTPs could increase the relative abundance of Lactobacillus, Bacteroides and Akkermansia and reduce the relative abundance of Lachnospiraceae_NK4A136_group and Rikenellaceae_RC9_gut_group. These results demonstrate that SCPII possesses potential immunoregulatory activities in cyclophosphamide-induced mice by regulating intestinal microbiota diversity and improving immune organs, enhancing the proliferation ability of macrophages and splenocyte proliferation, and enhancing intestinal physical barrier function, which might provide important evidence for the development and utilization of the viscera of sea cucumber.

Effect of sea cucumber peptides on the immune response and gut microbiota composition in ovalbumin-induced allergic mice.

The prevalence of food allergies has increased in Asian countries. The aim of this study was to determine the potential value of sea cucumber peptide (SCP) for anti-allergic therapeutics in terms of their effect on immune response and gut microbiota composition. Results exhibited that SCP could significantly improve the allergy symptoms caused by ovalbumin and could reduce the risk of IgE mediated allergic disorders, as well as repair the morphological damage in the colon. Flow cytometry analysis indicated that SCP could improve the ratio of CD4+/CD8+ T lymphocytes. 16S rRNA results indicated that SCP could differently impact the composition of microbiota. The relative abundances of Bacteroidetes and Firmicutes and the Bacteroidetes/Firmicutes ratio were altered in normal mice. When compared with the OVA treated group, the SCP treated groups showed an increase in the relative abundance of Lachnospiraceae, Muribaculaceae and Ruminococcaceae, and a decrease in Bacteroidaceae, Prevotellaceae, and Lactobacillaceae. These results demonstrate that SCP exhibits potential antiallergic activities in a mouse model of ovalbumin allergy by regulating intestinal microbiota diversity and upregulating the immune response of T lymphocyte subpopulations, which might provide important evidence that SCP can be developed into a novel functional food for inhibiting ovalbumin allergy.

Effect of water sorption on glass transition and microstructural variation of dextran & sugar mixtures.

Dextran is widely used as a model polysaccharide to study the interactions between polysaccharides and small molecule sugars. This study examined water sorption isotherms and glass transition temperatures (Tg) of mixtures of dextran with trehalose, lactose and sucrose for understanding how different disaccharides affect dextran's processing adaptation and storage performance relevant to water sorption. At the same chemical composition, monolayer water (m0) was dextran & sucrose (dex&suc) > dextran & trehalose (dex&tre) > dextran & lactose (dex&lac). The higher ratios of dextran, the higher was the Guggenheim constant (C) value of the mixtures. The compatibility of dextran and disaccharides was dex&tre > dex&lac > dex&suc. Gordon-Taylor model showed dex&tre (2:1) best inhibited water plasticization. Furthermore, trehalose and lactose were more effective in preventing morphological changes of hydrous matrices in the mixtures. The crystallinities of samples at 43% relative humidity (RH) were slightly lower than that at 11% RH.

Carboxymethylation of (1 → 6)-α-dextran from Leuconostoc spp.: Effects on microstructural, thermal and antioxidant properties.

The carboxymethylated (1 â†’ 6)-α-dextran (CM-dex) was synthesized by introducing carboxymethyl groups at different degrees of substitution (DS). The resulting dex1-1, dex2-1, dex3-1, and dex4-1 products had degrees of substitution of 0.57, 0.78, 1.13, and 1.25, respectively. The dex3-1 showed the highest glass transition temperature (Tg) of 215.96 °C, whereas Tg of pure dextran was 149.83 °C. TGA results indicated that the residual loss was reduced along with the increase of DS in the high-temperature region (450-600 °C). Besides, the CM-dex had stronger scavenging capacity against OH radicals but lower scavenging capacity for DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals compared to that of pure dextran. The carboxymethylation of (1 â†’ 6)-α-dextran will extend the applications for modified dextran.

Wheat germ glycoprotein regionally modulates immunosuppressed mouse intestinal immunity function from early life to adulthood.

Wheat germ glycoprotein (WGP) is widely used due to its nutritional benefits and biological activity. This study evaluated the effects of WGP on intestinal-immunosuppressed mice from early life to adulthood and detected the underlying mechanism. The results revealed that WGP demonstrated no clinical side effects on the body index, serum total IgA level, protein expression and the morphology of intestine in newborn mice. In the phase of life, compared with the cyclophosphamide-treated group (CG), WGP clearly promoted the secretion of sIgA and effectively regulated the cytokine gene (IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-5, IL-17, and TGF-ß1) expression in the intestine. Furthermore, WGP promoted the expression of CD40L and CD40, phosphorylation of IKKα/ß and transcription of NF-κB-p65. The data as reported in this present analysis suggest that WGP can improve the intestinal immunity of newborn mice to adulthood via the CD40L-CD40-IKKα/ß-NF-κB p65 signaling pathway.

Regulation of wheat germ polysaccharides in the immune response of mice from newborn to adulthood associated with intestinal microbiota.

The aim of this study was to determine the effects of wheat germ polysaccharides (WGPs), which are indigestible carbohydrate fibers, on mice in early life, and the changes leading to long-lasting consequences. We determined the influences of early life ceftriaxone and WGP treatment on intestinal microbiota and immunity both in newborn and adulthood mice. The results showed that ceftriaxone significantly altered the intestinal microbiota, short-chain fatty acids' (SCFAs) metabolism, organ index, and serum OVA-specific IgE levels in newborn mice. Comparing adulthood mice to ceftriaxone-treated mice, the diversity and composition of intestinal microbiota were significantly improved after WGP treatment. In addition, the levels of OVA-specific IgE in the WGP-treated mice were significantly decreased, and the expression of cytokines (IL-2, IL-4, IL-6, IFN-γ, and TNF-α) were obviously increased. Therefore, we speculate that the mechanism of action of the indigestible carbohydrate fibers of WGPs is through maintaining immune homeostasis in newborns, which may partly last into adulthood. More importantly, this may be closely related to alterations in the intestinal microbiota.

A novel wheat germ polysaccharide: Structural characterization, potential antioxidant activities and mechanism.

A wheat germ polysaccharide (WGP-1) was isolated from wheat germ through hot-water (pH = 7.3) extraction and further fractionated by anion-exchange column using DEAE-52 cellulose column and purified by gel-permeation chromatography using Sephacryl S-500 column. WGP-1 was mainly consisted with rhamnose, arabinose, xylose, mannose, galactose and glucose, and linked with 1→, 1 â†’ 2, 1 â†’ 4, 1 â†’ 3 and 1 â†’ 6 glucosidic bands. The present study was designed to evaluate the antioxidant activities of WGP-1 in oleic acid (OA)-induced HepG2 cell model with its related mechanisms. Results showed that WGP-1 remarkably elevated the expression of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC), and decreased the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) in OA-treated cell. WGP-1 was found to promote the expression of PI3K, the phosphorylation of AKT and the translocation of Nrf2, further increased the expression of HO-1 in OA-induced cells. These results demonstrate again that WGP-1 can effectively improve OA-induced oxidative damage, probably by up-regulating of PI3K expression, Nrf2 translocation, and AKT phosphorylation.

Hot water extraction and artificial simulated gastrointestinal digestion of wheat germ polysaccharide.

The conditions of wheat germ polysaccharide extraction were determined using the water extraction method. The gastric and intestinal digestion of wheat germ polysaccharide was analyzed in vitro. According to a single factor experiment and response surface experiment, the optimal extraction conditions of wheat germ polysaccharide were the following: liquid-solid ratio, 5:1 mL/g; extraction temperature, 69 °C; repetition of the extracting procedure, 3 times; extraction time, 44 min. Under such conditions, wheat germ polysaccharide yield was 8.89% ±â€¯0.002%. In the in vitro gastrointestinal experiment, wheat germ polysaccharide was digested and the content of reducing sugar increased during the digestion period, indicating that this increase might be due to the breakdown of glycosidic bonds in the wheat germ polysaccharide. Furthermore, no monosaccharide was detected, demonstrating that the gastrointestinal digestion did not cause free monosaccharide released. These results show some preliminary characteristics of the wheat germ polysaccharide in vitro digestion, providing a theoretical basis for further understanding wheat germ polysaccharide properties.

Dietary supplementation with purified wheat germ glycoprotein improve immunostimulatory activity in cyclophosphamide induced Balb/c mice.

Wheat germ has been reported to possess critical biological activities. However, the molecular mechanisms are not fully illuminated. In this work, the immunostimulating activity of a newly purified wheat germ glycoprotein (WGPII) was investigated in immunosuppressed Balb/c mice. Subsequently, WGPII increased the indices of spleen and thymus. Histopathological analysis indicated the protective function of WGPII against cyclophosphamide (CTX) induced immunosuppression. It also showed that WGPII could strengthen macrophage phagocytosis capacity, and NK cell activity. Following, flow cytometry was used to investigate spleen T lymphocyte subpopulations, real-time polymerase chain reaction (RT-PCR) was used to investigate spleen secreted cytokines, and western blot was used to analysis the receptor protein and protein kinase. These results indicated that WGPII could enhance CD4+ and CD8+ splenic T lymphocytes, inflammatory cytokines (IL-ß, IL-6, IL-12, TNF-α mRNA), receptor protein (TLR2, TLR4) and protein kinase (IRAK4, TRAF6, TAK1, p38-MAPK, pho-p38-MAPK, NF-κB p65, and nucleu-NF-κB p65) production. This study suggests that WGPII, used as a dietary supplement, could be considered a good candidate to improve immune functions.

Structural characterization of a novel glycoprotein in wheat germ and its physicochemical properties.

Wheat germ is well known for as a rich source of nutrients. In this study, a novel water soluble wheat germ glycoprotein (WGPII), with an average molecular weight of 14.5 kDa, was extracted from commercial wheat germ. The protein segments occupy 70.38% (w/w) of WGPII, and are rich in glutamic acid. The sugar residues of WGPII are primarily composed of (1 → 5)-linked α-l-Araf, (1 → 3, 6)-linked-α-d-Manp, (1→)-α-d-Glcp, (1 → 6)-linked-α-d-Glcp, (1 → 6)-linked-α-d-Galp, (1 → 4)-linked-α-d-Xylp and (1 → 4,6)-linked-α-d-Glcp. The protein and polysaccharide parts are linked by O-linkage bonds. WGPII is highly stable in aqueous solution at low concentrations (0.1-1 mg/mL), and show high thermo stability.

Structural Variation and Microrheological Properties of a Homogeneous Polysaccharide from Wheat Germ.

A novel polysaccharide (WGP) was purified from crude wheat germ polysaccharide by Sephacryl S-500HRgel filtration. The molecular weight of WGP was determined as 4.89 × 106 Da and consisted of arabinose, xylose, glucose, and galactose. Methylation analysis and 1D/2D nuclear magnetic resonance was used to analyze the structural characterization of WGP. WGP was mainly a backbone composed of (1 → 4)-linked-ß-d-Xylp (19.01%) and (1 → 3, 4)-linked-ß-d-Xylp (26.27%) residues, which was branched of (1 → 5)-linked α-l-Araf (28.09%) and (1 → 3,6)-linked ß-d-Galp (12.11%) with ß-d-Glcp (14.52%) as terminal unit. The calculated values of Turbiscan stability indexes suggested that WGP (0.1-0.5 mg/mL) is a stable system. Microrheology results showed that WGP can form gel behavior when the concentration of WGP ranges from 0.1 to 3 mg/mL. Results of in vitro assays showed that WGP could cause the proliferation of RAW264.7 macrophages, upregulating the release of TNF-α and IL-8 in the lymphocytes.