The GE296_RS03820 and GE296_RS03830 genes are involved in capsular polysaccharide biosynthesis in Riemerella anatipestifer.

Riemerella anatipestifer is a pathogenic bacterium that causes duck serositis and meningitis, leading to significant harm to the duck industry. To escape from the host immune system, the meningitis-causing bacteria must survive and multiply in the bloodstream, relying on specific virulence factors such as capsules. Therefore, it is essential to study the genes involved in capsule biosynthesis in R. anatipestifer. In this study, we successfully constructed gene deletion mutants Δ3820 and Δ3830, targeting the GE296_RS03820 and GE296_RS03830 genes, respectively, using the RA-LZ01 strain as the parental strain. The growth kinetics analysis revealed that these two genes contribute to bacterial growth. Transmission and scanning electron microscopy (TEM and SEM) and silver staining showed that Δ3820 and Δ3830 produced the altered capsules and compounds of capsular polysaccharides (CPSs). Serum resistance test showed the mutants also exhibited reduced C3b deposition and decreased resistance serum killing. In vivo, Δ3820 and Δ3830 exhibited markedly declining capacity to cross the blood-brain barrier, compared to RA-LZ01. These findings indicate that the GE296_RS03820 and GE296_RS03830 genes are involved in CPSs biosynthesis and play a key role in the pathogenicity of R. anatipestifer. Furthermore, Δ3820 and Δ3830 mutants presented a tendency toward higher survival rates from RA-LZ01 challenge in vivo. Additionally, sera from ducklings immunized with the mutants showed cross-immunoreactivity with different serotypes of R. anatipestifer, including 1, 2, 7 and 10. Western blot and SDS-PAGE assays revealed that the altered CPSs of Δ3820 and Δ3830 resulted in the exposure of some conserved proteins playing the key role in the cross-immunoreactivity. Our study clearly demonstrated that the GE296_RS03820 and GE296_RS03830 genes are involved in CPS biosynthesis in R. anatipestifer and the capsule is a target for attenuation in vaccine development.

Metabolomics study of dietary Pleurotus eryngii ß-type glycosidic polysaccharide on colitis induced by dextran sodium sulfate in mice - Exploration for the potential metabolic indicators in urine and serum.

Pleurotus eryngii, an edible mushroom recognized for its potent polysaccharides, demonstrates significant regulatory effects on metabolic processes. ß-glucan (WPEP) derived from P. eryngii has been noted for its therapeutic potential, exhibiting notable benefits in alleviating colonic inflammation and restructuring gut microbiota in mice treated with dextran sodium sulfate (DSS). This study focuses on utilizing DSS-induced colitis mice to explore the efficacy and underlying mechanisms of WPEP in ameliorating colitis, employing a metabolomics approach analyzing urine and serum. The findings reveal that WPEP administration effectively regulates metabolic imbalances in DSS mice, impacting purine metabolism, pentose and glucuronic acid interconversion, amino acid metabolism, primary bile acid biosynthesis, citric acid cycle, and lipid metabolism. Furthermore, WPEP demonstrates a capacity to modulate colitis by regulating diverse metabolic pathways, consequently influencing intestinal barrier integrity, motility, inflammation, oxidative stress, and immunity. These insights suggest that WPEP is a promising food component for managing inflammatory bowel diseases.

Enhanced stability of encapsulated lemongrass essential oil in chitosan-gelatin and pectin-gelatin biopolymer matrices containing ZnO nanoparticles.

The use of essential oils is widespread in various fields such as pharmacy, pest control, and active packaging. However, their instability and short-term effects require methods to enhance their durability and effectiveness. Encapsulation in biopolymer matrices appears to be a promising approach due to the environmental safety and cost-effectiveness of such formulations. In this study, different oil-in-water emulsions were prepared by mixing chitosan-gelatin (C-G) or pectin-gelatin (P-G) solutions with lemongrass essential oil (LG). ZnO NPs were used as an additional active component. Encapsulation in biopolymer matrices resulted in stable emulsions with a significantly slower release of LG, and ZnO NPs further suppressed LG release, particularly in the P-G emulsion. They also contributed to the stability of the emulsions and a decrease in the average droplet size of LG. Furthermore, the presence of LG and ZnO NPs improved the smoothness of the films prepared from the emulsions and dispersions using the casting technique. SEM/EDS analysis confirmed the homogeneous distribution of ZnO NPs in both C-G and P-G films. By adjusting the type and content of the biopolymers and NPs, such emulsions could be effectively utilized in various applications where controlled release of active components is required.

Structural analysis and blood-enriching effects comparison based on biological potency of Angelica sinensis polysaccharides.

Angelica sinensis is a long-standing medicine used by Chinese medical practitioners and well-known for its blood-tonic and blood-activating effects. Ferulic acid, ligustilide, and eugenol in Angelica sinensis activate the blood circulation; however, the material basis of their blood-tonic effects needs to be further investigated. In this study, five homogeneous Angelica sinensis polysaccharides were isolated, and their sugar content, molecular weight, monosaccharide composition, and infrared characteristics determined. Acetylphenylhydrazine (APH) and cyclophosphamide (CTX) were used as inducers to establish a blood deficiency model in mice, and organ indices, haematological and biochemical parameters were measured in mice. Results of in vivo hematopoietic activity showed that Angelica sinensis polysaccharide (APS) could elevate erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF), and interleukin-3 (IL-3) serum levels, reduce tumor necrosis factor-α (TNF-α) level in mice, and promote hematopoiesis in the body by regulating cytokine levels. Biological potency test results of the in vitro blood supplementation indicated strongest tonic activity for APS-H2O, and APS-0.4 has the weakest haemopoietic activity. The structures of APS-H2O and APS-0.4 were characterized, and the results showed that APS-H2O is an arabinogalactan glycan with a main chain consisting of α-1,3,5-Ara(f), α-1,5- Ara(f), ß-1,4-Gal(p), and ß-1,4-Gal(p)A, and two branched chains of ß-t-Gal(p) and α-t-Glc(p) connected to each other in a (1→3) linkage to α-1,3,5-Ara(f) on the main chain. APS-0.4 is an acidic polysaccharide with galacturonic acid as the main chain, consisting of α-1,4-GalA, α-1,2-GalA, α-1,4-Gal, and ß-1,4-Rha. In conclusion, APS-H2O can be used as a potential drug for blood replenishment in patients with blood deficiency, providing a basis for APS application in clinical treatment and health foods, as well as research and development of new polysaccharide-based drugs.

Effects of steam explosion pretreatment on the digestive properties and gut microbiota of Laminaria japonica polysaccharide.

BACKGROUND: Laminaria japonica polysaccharide, which is an important bioactive substance of Laminaria japonica with anti-inflammatory and antioxidant effects. In this study, the molecular weight, functional groups and surface morphology were investigated to evaluate the digestive properties of Laminaria japonica polysaccharide before and after steam explosion. RESULTS: The results indicated that the Laminaria japonica polysaccharide entered the large intestine to be utilized by the gut microbiota after passing through the oral, gastric and small intestinal. Meanwhile, Laminaria japonica polysaccharide of steam explosion promoted the growth of beneficial bacteria Phascolarctobacterium and Intestinimonas, and increased the content of acetic, propionic and butyric acids, which was 2.29-folds, 2.60-folds and 1.63-folds higher than the control group after 48 h of fermentation. CONCLUSION: This study reveals that the effect of steam explosion pretreatment on the digestion in vitro and gut microbiota of Laminaria japonica polysaccharide will provide a basic theoretical basis for the potential application of Laminaria japonica polysaccharide as a prebiotic in the food industry. © 2024 Society of Chemical Industry.

An approach to manufacturing well-being milk chocolate in partial replacement of lecithin by the functional plant-based combination.

Lecithin is constituted of a glycerophospholipid mixture and is abundantly used as an emulsifying agent in various food applications including chocolate production. However, overconsumption of lecithin may create an adverse effect on human health. Thus, this study aims to replace the lecithin with plant-based gums. Different ratios of guar and arabic gum (25%-75%) and their blend (25%-75%) were employed as partial replacement of lecithin. Milk chocolate prepared using 40% guar gum (60GGL [guar gum, lecithin]), 25% arabic gum (75AGL [arabic gum, lecithin]), and a blend of 15 arabic gum and 10 guar gum (65AGGL [arabic gum, guar gum, lecithin]) showed similar rheological behavior as compared to control chocolate (100% lecithin). The fat content of 65AGGL (37.85%) was significantly lower than that of the control sample (43.37%). Rheological behavior exhibited shear-thinning behavior and samples (60GGL-75GGL-80GGL, 65AGL-75AGL, and 65AGGL-75AGGL) showed similar rheological properties as compared to control. The chocolate samples (60GGL and 65AGGL) showed significantly (p < .05) higher hardness values (86.01 and 83.55 N) than the control (79.95 N). As well, gum-added chocolates exhibited higher thermal stability up to 660°C as compared to the control sample. The Fourier transform infrared spectroscopy (FTIR) analysis revealed predominant ß-(1 → 4) and ß-(1 → 6) glycosidic linkages of the gums and lecithin. Sensory evaluation revealed a comparable score of gum-added milk chocolate in comparison to control samples in terms of taste, texture, color, and overall acceptance. Thus, plant exudate gums could be an excellent alternative to lecithin in milk chocolate, which can enhance the textural properties and shelf life.

Proteomic analysis of the effects of Dictyophora polysaccharide on arsenic-induced hepatotoxicity in rats.

Arsenic (As) is a highly toxic environmental toxicant and a known human carcinogen. Long-term exposure to As can cause liver injury. Dictyophora polysaccharide (DIP) is a biologically active natural compound found in the Dictyophora with excellent antioxidation, anti-inflammation, and immune protection properties. In this study, the Sprague-Dawley (SD) rat model of As toxicity was established using a feeding method, followed by DIP treatment in rats with As-induced liver injury. The molecular mechanisms of As toxicity to the rat liver and the protective effect of DIP were investigated by proteomic studies. The results showed that 172, 328 and 191 differentially expressed proteins (DEPs) were identified between the As-exposed rats versus control rats (As/Ctrl), DIP treated rats versus As-exposed rats (DIP+As/As), and DIP treated rats versus control rats (DIP+As /Ctrl), respectively. Among them, the expression of 90 DEPs in the As/Ctrl groups was reversed by DIP treatment. As exposure caused dysregulation of metabolic pathways, mitochondria, oxidative stress, and apoptosis-related proteins in the rat liver. However, DIP treatment changed or restored the levels of these proteins, which attenuated the damage to the livers of rats caused by As exposure. The results provide new insights into the mechanisms of liver injury induced by As exposure and the treatment of DIP in As poisoning.

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions.

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Targeting TGFß receptor-mediated snail and twist: WSG, a polysaccharide from Ganoderma lucidum, and it-based dissolvable microneedle patch suppress melanoma cells.

Cutaneous melanoma is a lethal skin cancer variant with pronounced aggressiveness and metastatic potential. However, few targeted medications inhibit the progression of melanoma. Ganoderma lucidum, which is a type of mushroom, is widely used as a non-toxic alternative adjunct therapy for cancer patients. This study determines the effect of WSG, which is a water-soluble glucan that is derived from G. lucidum, on melanoma cells. The results show that WSG inhibits cell viability and the mobility of melanoma cells. WSG induces changes in the expression of epithelial-to-mesenchymal transition (EMT)-related markers. WSG also downregulates EMT-related transcription factors, Snail and Twist. Signal transduction assays show that WSG reduces the protein levels in transforming growth factor ß receptors (TGFßRs) and consequently inhibits the phosphorylation of intracellular signaling molecules, such as FAK, ERK1/2 and Smad2. An In vivo study shows that WSG suppresses melanoma growth in B16F10-bearing mice. To enhance transdermal drug delivery and prevent oxidation, two highly biocompatible compounds, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), are used to synthesize a dissolvable microneedle patch that is loaded with WSG (MN-WSG). A functional assay shows that MN-WSG has an effect that is comparable to that of WSG alone. These results show that WSG has significant potential as a therapeutic agent for melanoma treatment. MN-WSG may allow groundbreaking therapeutic approaches and offers a novel method for delivering this potent compound effectively.

Structure and in vitro antiproliferative activity against breast cancer cells of the cell-wall polysaccharide from the marine bacterium Kangiella japonica KMM 3899T.

Kangiella japonica KMM 3899T is a Gram-negative bacterium isolated from a sandy sediment sample collected from the Sea of Japan. Here the results of the structure and the biological activity against breast cancer cells of the cell-wall polysaccharide from K. japonica KMM 3899T have been described. The structure of the repeating unit of the polysaccharide was elucidated using chemical analysis and NMR spectroscopy: →4)-α-L-GalpNAc3AcA-(1 â†’ 3)-α-D-GlcpNAc-(1 â†’ 4)-ß-D-GlcpNAc3NAcAN-(1→. The cell-wall polysaccharide had an antiproliferative effect against T-47D cells. Flow cytometric and Western blot analysis revealed that the polysaccharide induced S phase arrest and mitochondrial-dependent apoptosis.

Polyelectrolyte complexes of chitosan and hyaluronic acid or carboxymethylpullulan and their aminoguaiacol derivatives with biological activities as potential drug delivery systems.

Polyelectrolyte complexes (PECs) were elaborated from chitosan as cationic polymer and carboxy-methylpullulan (CMP), hyaluronic acid (HA) and their derivatives grafted with aminoguaiacol (G) with different degrees of substitution (DSGA) with the aim of obtaining nanogels for drug delivery. For each couple of polysaccharides, the charge ratios giving the smaller size with the lower PDI were selected to produce PECs. CMP_CHIT and CMP-G_CHIT PECs had smaller sizes (220-280 nm) than HA_CHIT and HA-G_CHIT PECs (280-390 nm). PECs were stable at 4 °C during 28 days at pH 5. In phosphate buffer saline (PBS) at pH 7.4, at 4 °C, a better stability of PECs based on CMP-G derivatives was observed. The hydrophobic associations between aminoguaiacol groups (highlighted by measurements of pyrene fluorescence) led to a better PECs' stabilization in PBS. The PECs' antioxidant and antibacterial activities were demonstrated and related to the DSGA. Diclofenac and curcumin were used as drug models: their loading reached 260 and 53 µg/mg PEC, respectively. The release of diclofenac in PBS at 37 °C followed a quasi-Fickian diffusion mechanism with release constant between 0.88 and 1.04 h-1. The curcumin release followed a slow linear increase in PBS/EtOH (60/40 V/V) with an effect of DSGA.

Effects of a diet supplemented with polysaccharides from Pogostemon cablin on growth performance, meat quality, and antioxidant capacity in Chongren Partridge chickens.

In this study, the Pogostemon cablin polysaccharides (PCPs) were heteropolysaccharides with molecular weights of 63.17 kDa and 8.99 kDa, and their total carbohydrate content was 76.17 ± 0.23%, uronic acid content was 19.92 ± 0.42%, and protein content was 1.24 ± 0.07%. PCP is composed of arabinose, galactose, glucose, and glucuronic acid, with a molar ratio of 0.196:0.249:0.451:0.104. In addition, we further investigated the effects of the diet supplemented with different doses of PCP on growth performance, meat quality, and anti-oxidant capacity in Chongren Partridge chickens. A total of 200 chickens were randomly allocated into 4 treatments, and fed with a basal diet of 0 (CON), 200 (LPCP), 400 (MPCP), and 800 (HPCP) mg/kg PCP for a 14-day prefeeding period and a formal experimental period of 56 days. Results showed that dietary PCP significantly increased final body weight (BW), average daily gain (ADG), and decreased feed-to-gain ratio (F/G) from days 1 to 56. Meanwhile, dietary PCP reduced yellowness (b∗) values and increased redness (a∗) values at 24 h in breast muscles (p < 0.05). Furthermore, LPCP and MPCP significantly increased the level of guanylic acid (GMP) (p < 0.05). MPCP increased the content of free amino acids (isoleucine, leucine, lysine, methionine, threonine, valine, alanine, glutamic acid, serine, cysteine), total essential amino acid (EAA), total flavor amino acid (FAA), total AA, the content of fatty acids (c14:1, c16:1, and c22:2), and monounsaturated fatty acids (MUFAs) in the breast muscle when compared to CON (p < 0.05). In addition, MPCP significantly reduced the content of malondialdehyde (MDA) and increased the transcript abundances of fatty acid desaturase 2 (FADS2), fatty acid synthase (FAS), lipoprotein lipase (LPL), and sterol regulatory element binding protein-1 (SREBP-1) in the breast muscles of the chickens (p < 0.05). In light of the aforementioned results, PCP at 400 mg/kg could be used as an effective additive because it not only promotes the growth performance of Chongren Partridge chickens but also shows a conducive role in meat quality, especially in meat flavor.

Modulation of cyclophosphamide-induced immunosuppression and intestinal flora in broiler by deep eutectic solvent extracted polysaccharides of Acanthopanax senticosus.

Introduction: The aim of this experiment was to investigate the modulation effect of Acanthopanax senticosus polysaccharide (ASPS-PD) extracted with deep eutectic solvent on cyclophosphamide-induced immunosuppression in broilers and its modulation of the gut microbiota of broilers. Methods: The 108 one-day-old broilers were divided into six groups, including the control group, the Cyclophosphamide (CY) model group, the ASPS-PD control group, the ASPA-PD high and low dose groups and the Astragalus polysaccharide group. Body weight, feed intake, feed conversion ratio, and immune organ index of broilers at 7, 14, and 21 days were determined; IL-2, IFN-γ, and lgG1 levels were determined by enzyme-linked immunosorbent assay (ELISA); Broiler caeca feces were analyzed by amplification and 16S rRNA sequencing. Results: The results showed that ASPS-PD can restore growth performance, increase immune organ index and improve serum cytokine levels of IL-2 and IFN-γ and immunoglobulin lgG1 levels in CY-treated broilers. The analysis of cecum flora showed that ASPS-PD can promote the proliferation of beneficial bacteria and reduce the number of harmful bacteria, regulating intestinal flora. Discussion: Therefore, ASPA-PD may be a potential novel immunomodulator to ameliorate CY-induced immunosuppression and intestinal flora dysregulation in broiler.

Recent Progress in Polysaccharide-Based Materials for Energy Applications: A Review.

In recent years, polysaccharides have emerged as a promising alternative for the development of environmentally friendly materials. Polysaccharide-based materials have been mainly studied for applications in the food, packaging, and biomedical industries. However, many investigations report processing routes and treatments that enable the modification of the inherent properties of polysaccharides, making them useful as materials for energy applications. The control of the ionic and electronic conductivities of polysaccharide-based materials allows for the development of solid electrolytes and electrodes. The incorporation of conductive and semiconductive phases can modify the permittivities of polysaccharides, increasing their capacity for charge storage, making them useful as active surfaces of energy harvesting devices such as triboelectric nanogenerators. Polysaccharides are inexpensive and abundant and could be considered as a suitable option for the development and improvement of energy devices. This review provides an overview of the main research work related to the use of both common commercially available polysaccharides and local native polysaccharides, including starch, chitosan, carrageenan, ulvan, agar, and bacterial cellulose. Solid and gel electrolytes derived from polysaccharides show a wide range of ionic conductivities from 0.0173 × 10-3 to 80.9 × 10-3 S cm-1. Electrodes made from polysaccharides show good specific capacitances ranging from 8 to 753 F g-1 and current densities from 0.05 to 5 A g-1. Active surfaces based on polysaccharides show promising results with power densities ranging from 0.15 to 16 100 mW m-2. These investigations suggest that in the future polysaccharides could become suitable materials to replace some synthetic polymers used in the fabrication of energy storage devices, including batteries, supercapacitors, and energy harvesting devices.

Modification of the Antibiotic, Colistin, with Dextrin Causes Enhanced Cytotoxicity and Triggers Apoptosis in Myeloid Leukemia.

Introduction: Acute myeloid leukemia (AML) remains difficult to treat due to its heterogeneity in molecular landscape, epigenetics and cell signaling alterations. Precision medicine is a major goal in AML therapy towards developing agents that can be used to treat patients with different 'subtypes' in combination with current chemotherapies. We have previously developed dextrin-colistin conjugates to combat the rise in multi-drug resistant bacterial infections and overcome dose-limiting nephrotoxicity. Recent evidence of colistin's anticancer activity, mediated through inhibition of intracellular lysine-specific histone demethylase 1 (LSD1/KDM1A), suggests that dextrin-colistin conjugates could be used to treat cancer cells, including AML. This study aimed to evaluate whether dextrin conjugation (which reduces in vivo toxicity and prolongs plasma half-life) could enhance colistin's cytotoxic effects in myeloid leukemia cell lines and compare the intracellular uptake and localization of the free and conjugated antibiotic. Results: Our results identified a conjugate (containing 8000 g/mol dextrin with 1 mol% succinoylation) that caused significantly increased toxicity in myeloid leukemia cells, compared to free colistin. Dextrin conjugation altered the mechanism of cell death by colistin, from necrosis to caspase 3/7-dependent apoptosis. In contrast, conjugation via a reversible ester linker, instead of an amide, had no effect on the mechanism of the colistin-induced cell death. Live cell confocal microscopy of fluorescently labelled compounds showed both free and dextrin-conjugated colistins were endocytosed and co-localized in lysosomes, and increasing the degree of modification by succinoylation of dextrin significantly reduced colistin internalization. Discussion: Whilst clinical translation of dextrin-colistin conjugates for the treatment of AML is unlikely due to the potential to promote antimicrobial resistance (AMR) and the relatively high colistin concentrations required for anticancer activity, the ability to potentiate the effectiveness of an anticancer drug by polymer conjugation, while reducing side effects and improving biodistribution of the drug, is very attractive, and this approach warrants further investigation.

Effect of pH on the soybean whey protein-gum arabic emulsion delivery systems for curcumin: Emulsifying, stability, and digestive properties.

A novel curcumin (CUR) delivery system was developed using soybean whey protein (SWP)-based emulsions, enhanced by pH-adjustment and gum arabic (GA) modification. Modulating electrostatic interactions between SWP and GA at oil/water interface, pH provides favorable charging conditions for stable distribution between droplets. GA facilitated the SWP form a stable interfacial layer that significantly enhanced the emulsifying properties and CUR encapsulation efficiency of the system at pH 6.0, which were 90.15 ± 0.67%, 870.53 ± 3.22 m2/g and 2157.62 ± 115.31%, respectively. Duncan's test revealed significant improvements in thermal, UV, oxidative, and storage stabilities of CUR (P < 0.05). At pH 6.0, GA effectively protected CUR by inhibiting SWP degradation during gastric digestion and promoting the release of CUR by decreasing steric hindrance with oil droplets during intestinal digestion, achieving the highest CUR bioaccessibility (69.12% ± 0.28%) based on Duncan's test. The SWP-GA-CUR emulsion delivery system would be a novel carrier for nutrients.

Hericium erinaceus polysaccharides ameliorate nonalcoholic fatty liver disease via gut microbiota and tryptophan metabolism regulation in an aged laying hen model.

Polysaccharides extracted from Hericium erinaceus (HEP) exhibit hepatoprotective activity in the alleviation of non-alcoholic fatty liver disease (NAFLD); however, the mechanisms underlying whether and how HEP regulation of the gut microbiota to alleviate liver-associated metabolic disorders are not well understood. This study used an aged laying hen model to explore the mechanisms through which HEP alleviates NAFLD, with a focus on regulatory function of HEP in the gut microbiome. The results showed that HEP ameliorated hepatic damage and metabolic disorders by improving intestinal barrier function and shaping the gut microbiota and tryptophan metabolic profiles. HEP increased the abundance of Lactobacillus and certain tryptophan metabolites, including indole-3-carboxylic acid, kynurenic acid, and tryptamine in the cecum. These metabolites upregulated the expression of ZO-1 and Occludin by activating the AhR and restoring the intestinal barrier integrity. The increased intestinal barrier functions decreased LPS transferring from the intestine to the liver, inhibited hepatic LPS/TLR4/MyD88/NF-κB pathway activation, and reduced hepatic inflammatory response and apoptosis. Fecal microbiota transplantation experiments further confirmed that the hepatoprotective effect is likely mediated by HEP-altered gut microbiota and their metabolites. Overall, dietary HEP could ameliorate the hepatic damage and metabolic disorders of NAFLD through regulating the "gut-liver" axis.

ι-Carrageenan catabolism is initiated by key sulfatases in the marine bacterium Pseudoalteromonas haloplanktis LL1.

Marine bacteria contribute substantially to cycle macroalgae polysaccharides in marine environments. Carrageenans are the primary cell wall polysaccharides of red macroalgae. The carrageenan catabolism mechanism and pathways are still largely unclear. Pseudoalteromonas is a representative bacterial genus that can utilize carrageenan. We previously isolated the strain Pseudoalteromonas haloplanktis LL1 that could grow on ι-carrageenan but produce no ι-carrageenase. Here, through a combination of bioinformatic, biochemical, and genetic analyses, we determined that P. haloplanktis LL1 processed a desulfurization-depolymerization sequential pathway for ι-carrageenan utilization, which was initiated by key sulfatases PhSulf1 and PhSulf2. PhSulf2 acted as an endo/exo-G4S (4-O-sulfation-ß-D-galactopyranose) sulfatase, while PhSulf1 was identified as a novel endo-DA2S sulfatase that could function extracellularly. Because of the unique activity of PhSulf1 toward ι-carrageenan rather than oligosaccharides, P. haloplanktis LL1 was considered to have a distinct ι-carrageenan catabolic pathway compared to other known ι-carrageenan-degrading bacteria, which mainly employ multifunctional G4S sulfatases and exo-DA2S (2-O-sulfation-3,6-anhydro-α-D-galactopyranose) sulfatase for sulfate removal. Furthermore, we detected widespread occurrence of PhSulf1-encoding gene homologs in the global ocean, indicating the prevalence of such endo-acting DA2S sulfatases as well as the related ι-carrageenan catabolism pathway. This research provides valuable insights into the enzymatic processes involved in carrageenan catabolism within marine ecological systems.IMPORTANCECarrageenan is a type of linear sulfated polysaccharide that plays a significant role in forming cell walls of marine algae and is found extensively distributed throughout the world's oceans. To the best of our current knowledge, the ι-carrageenan catabolism in marine bacteria either follows the depolymerization-desulfurization sequential process initiated by ι-carrageenase or starts from the desulfurization step catalyzed by exo-acting sulfatases. In this study, we found that the marine bacterium Pseudoalteromonas haloplanktis LL1 processes a distinct pathway for ι-carrageenan catabolism employing a specific endo-acting DA2S-sulfatase PhSulf1 and a multifunctional G4S sulfatase PhSulf2. The unique PhSulf1 homologs appear to be widely present on a global scale, indicating the indispensable contribution of the marine bacteria containing the distinct ι-carrageenan catabolism pathway. Therefore, this study would significantly enrich our understanding of the molecular mechanisms underlying carrageenan utilization, providing valuable insights into the intricate roles of marine bacteria in polysaccharide cycling in marine environments.

Effects of ultrasound and thermal treatment on the interaction between hyaluronic acid and lactoferrin: Preparation, structures and functionalities.

Complexes of polysaccharides and proteins have superior physicochemical and functional properties compared to single proteins or polysaccharides. In this study, lactoferrin-hyaluronic acid (LF-HA) complexes were prepared by both ultrasonic and thermal treatment. Appropriate preparation conditions, including ultrasonic and thermal treatment conditions, have been established. The complexes formed by different methods were structurally characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis, fourier transform infrared spectroscopy, and circular dichroism spectroscopy. Ultrasound formed non-covalent binding, while thermal treatment generated covalent bonding, altering the structure of LF. The LF-HA complexes showed improved heat stability, foaming stability, emulsifying activity and antioxidant capacity, but deceased foaming ability. Iron binding ability could only be improved by HA through thermal treatment. Moreover, the in vitro digestibility of LF-HA complexes decreased to below 80 % compared to LF.

All-in-one polysaccharide hydrogel with resistant vascular burst pressure and cooperative wound microenvironment regulation for fatal arterial hemorrhage and diabetic wound healing.

Fatal massive hemorrhage and diabetic wound healing are world widely challenging in surgical managements, and uncontrolled bleeding, chronic inflammation and damaged remodeling heavily hinder the whole healing processes. Considering hemostasis, inflammation and wound microenvironment cooperatively affect the healing progression, we design all-in-one beta-glucan (BG) hybrid hydrogels reinforced with laponite nanoclay that demonstrate tunable tissue adhesion, resistant vascular burst pressure and cooperative wound microenvironment regulation for arterial hemostasis and diabetic wound prohealing. Those hydrogels had honeycomb-like porous microstructure with average pore size of 7-19 µm, tissue adhesion strength of 18-46 kPa, and vascular burst pressure of 58-174 mmHg to achieve superior hemostasis in rat liver and femoral artery models. They could effectively scavenge reactive oxygen species, transform macrophages from proinflammatory M1 into prohealing M2, and shorten the inflammation duration via synergistic actions of BG and nitric oxide (NO). Single treatment of NO-releasing BG hybrid hydrogels attained complete closure of diabetic wounds within 14 days, orchestrated to accelerate the epithelization and dermis growth, and restored normal vascularization, achieving high performance healing with optimal collagen deposition and hair follicle regeneration. Consequently, this work opens up a new avenue to design all-in-one polysaccharide hydrogels for applications in massive bleeding hemostats and diabetic wound dressings.