Search Results (471)

Oral joint supplements (OJSs), specifically those containing glucosamine and chondroitin sulfate, are some of the most popular feed additives fed by horse owners. However, evidence of the efficacy of these nutraceuticals in vivo is lacking. To investigate the impacts of an OJS on equine lameness, 40 geldings (18 ± 7 yr) with chronic lameness and AAEP lameness grades between 2 and 4 (as scored by a veterinary sports medicine and rehabilitation specialist) were enrolled in the study. Horses were stratified by lameness grade, BCS, and weight, and then randomly assigned to receive a placebo powder or an OJS daily for 6 wks. Stride length measurements and lameness evaluations were performed every 2 wk. There was no effect of treatment or treatment-by-day interaction for stride length, though day affected both walk (p = 0.04) and trot (p < 0.01). Only day affected lameness grade, with the lowest average score on d28 (p = 0.04). There was no evidence of supplementation improving gait symmetry over time. As such, there is no evidence to support efficacy of the tested OJS when fed for 6 wk. These results emphasize the importance of well-controlled studies and support continued development of evidence-based management strategies for equine joint health. Full article

A body of evidence suggests that upregulating O-GlcNAcylation, a reversible post-translational modification of serine and threonine residues on target proteins, is beneficial in neurological diseases. However, this phenomenon is currently underexplored in the pharmacotherapy of epilepsy. Therefore, we aimed to explore the potential effects of combining N-acetylglucosamine (GlcNAc), a precursor for O-GlcNAcylation, and a centrally acting benzodiazepine (diazepam) on oxidative stress, a known driver of epilepsy, and some epileptogenesis-associated genes. Mice (n = 10) were randomly assigned to treatment groups and treated with varied oral doses (100, 200, and 400 mg/kg) of GlcNAc in combination with diazepam (1 mg/kg) for 14 days. Following this, seizure was chemically induced with 70 mg/kg pentylenetetrazol intraperitoneally. Brains of treated mice were excised for antioxidant assays and to determine the expression of genes associated with epileptogenesis: potassium chloride co-transporter (KCC4), interleukin (IL-6), tumour necrosis factor-α (TNF-α), and brain-derived neurotrophic factor (BDNF). Our findings suggest that GlcNAc, when concurrently administered with diazepam, prevents oxidative stress and reduces the gene expression of IL-6, a cytokine associated with neuroinflammation and seizures, whilst increasing the gene expression of KCC4, an ion co-transporter that promotes antiepileptogenesis. Full article

Glucosamine (GlcN) is an essential amino monosaccharide widely used in pharmaceuticals, nutraceuticals, and cosmetics. Microbial fermentation presents a sustainable alternative to its traditional chemical production. However, in Saccharomyces cerevisiae, competitive carbon flux towards ethanol significantly limits GlcN yields. In this study, an S. cerevisiae strain for GlcN biosynthesis was engineered by integrating heterologous GlmD (glucosamine-6-phosphate deaminase) and GlmP (glucosamine-6-phosphate phosphatase) genes. To redirect carbon flux, the pyruvate decarboxylase genes pdc1, pdc5, and pdc6 were sequentially knocked out using the Clustered Regularly Interspaced Short Palindromic Repeats Cas9 (CRISPR-Cas9) approach, generating strains S. cerevisiaeGlmDP/pdc1Δ, GlmDP/pdc1Δpdc5Δ, and GlmDP/pdc1Δpdc5Δpdc6Δ. S. cerevisiae GlmDP/pdc1Δpdc5Δpdc6Δ achieved a GlcN titer of 2.20 ± 0.11 g/L, a 1.54-fold increase over the parental S. cerevisia GlmDP strain, while its ethanol yield decreased by 26%. This enhancement was achieved without significantly affecting cell growth or glucose consumption. Comparative transcriptomics between the triple-knockout and parental yeasts revealed 892 differentially expressed genes. Pathways related to glycolysis and ethanol formation were predominantly downregulated, whereas pathways potentially supporting GlcN synthesis were upregulated. The engineered strain demonstrated high genetic stability over 50 generations. Our findings demonstrate that disrupting ethanol formation is an effective strategy to enhance GlcN production in S. cerevisiae, providing valuable insights for carbon flux redistribution. Full article

Chitooligosaccharides (COS) are short-chain chitosan derivatives with a wide range of biomedical, agricultural, and environmental applications, including antimicrobial therapy, wound healing, and pollutant removal. Reliable quantification of COS is essential but currently relies on high-performance liquid chromatography, mass spectrometry, or capillary electrophoresis, which require costly equipment, complex sample preparation, and are unsuitable for routine or on-site applications. This study reports a rapid, solvent-free, colorimetric assay for COS based on the reaction of 5% aqueous ninhydrin with free amino groups in McIlvaine buffer. The assay was optimized using glucosamine as a model analyte, yielding maximal sensitivity at pH 7.0. The chromophore generated (Ruhemann’s purple) remained stable for over 120 min after reaction, allowing measurements to be taken without strict time constraints. Calibration was linear from 0.4 to 2.2 mM (R² = 0.9926), with low limits of detection (0.006 mM) and quantification (0.018 mM). Increasing absorbance with COS polymerization degree (DP1–DP6) demonstrates specificity for free amino groups, while N-acetyl glucosamine showed a negligible response. Furthermore, the assay was successfully adapted for solid-phase detection on ninhydrin-pretreated filter paper and nitrocellulose, with enhanced sensitivity. This simple, efficient, and low-cost method provides an accessible alternative to instrumental techniques, supporting COS monitoring in laboratory workflows and enabling portable applications in biomedicine, agriculture, and environmental diagnostics. Full article

The aim of this study is to investigate the effects and mechanisms of GS in relation to the production performance, eggshell quality, and liver health of aged laying hens. A total of 144 elderly laying hens were randomly divided into a control group, a 0.15% GS group, and a 0.35% GS group and fed for 4 weeks. The experimental results revealed that GS can significantly improve the laying rate, eggshell strength, and eggshell thickness of aged laying hens and reduce the feed-to-egg ratio (p < 0.05). Specifically, 0.35% GS can alleviate symptoms of hepatic steatosis; significantly reduce the levels of AST, TG, and MDA in serum; and increase the levels of ALB and GSH-Px (p < 0.05). The sequencing results demonstrated that GS significantly upregulated the expression of fatty acid breakdown and antioxidant genes, such as PPARA, ACOX1, GSTT1, and CAT, in the liver, while downregulating the expression of fatty acid synthesis and inflammatory genes such as PPARG, FASN, TGFBR2, and TNF-α (p < 0.05). Meanwhile, GS also increased the expression of uterine eggshell matrix protein genes (p < 0.05). In summary, GS improves liver health by regulating fatty acid metabolism, inflammation, and antioxidant pathways and enhances eggshell quality by promoting eggshell matrix protein synthesis. Full article

The interaction of a set of four N-acetyl-glucosamine (GlcNAc) glycomimetics with human N-acetyl-glucosaminidase (NAGLU), the genetically defective enzyme in patients suffering from mucopolysaccharidosis (MPS) IIIB, also known as Sanfilippo B syndrome, was investigated to identify potential pharmacological chaperones. Glycomimetic–NAGLU binding was initially studied by molecular docking simulations and a thermal shift assay. The effects of the glycomimetics on NAGLU activity enhancement were studied in fibroblast cells from seven MPS IIIB patients. A significant increase in NAGLU activity in four cell lines in the presence of glycomimetic MK 8719, a molecule tested in a Phase 1 study in healthy volunteers to treat Alzheimer’s disease, was demonstrated. Furthermore, MK 8719 prevented the increase in glycosaminoglycan (GAG) levels in four MPS IIIB fibroblast cells, suggesting that this molecule may be worth investigating further as a pharmacological chaperone for MPS IIIB. These results represent an important contribution towards the development of a specific therapy for MPS IIIB. Full article

Lactulose, a valuable functional disaccharide with pharmaceutical and food applications, is efficiently synthesized via enzymatic isomerization of lactose. This study developed an integrated strategy combining protein engineering of cellobiose 2-epimerase (CsCE) from Caldicellulosiruptor saccharolyticus and process optimization to enhance lactulose production. A dual-track engineering approach—incorporating flexible loop modulation (residues 161–193) and structure-guided sequence alignment with N-acetyl-D-glucosamine-2-epimerase—enabled the creation of two superior mutants, R17Q/L184S and R17Q/S142T. The R17Q/L184S variant exhibited a 37% increase in crude enzyme activity, improved thermostability (half-life of 200 min at 80 °C), and enhanced substrate affinity (K_m reduced by 23.2%). R17Q/S142T achieved a 21% higher specific activity (24.08 U/mg), the highest among all variants. Structural and molecular dynamics analyses revealed that L184S enriched hydrogen bonding and hydrophobic interactions, improving structural rigidity, while S142T introduced allosteric regulation that facilitated catalytic efficiency. Under optimized conditions (70 °C, pH 7.5, 40% lactose, 20 U/mL enzyme, 3 h), lactulose yield reached 75.6% with >95% purity. This work demonstrates the successful application of synergistic enzyme engineering and process intensification for high-efficiency lactulose biosynthesis, providing viable candidates and system solutions for industrial-scale production. Full article

The whitefly Bemisia tabaci is a globally invasive pest that threatens crop production through feeding and virus transmission. In this study, we identified genes encoding enzymes in the chitin metabolism pathway of B. tabaci—β-N-acetylglucosaminidase (BtNAG), N-acetylglucosamine kinase (BtNAGK), phosphoacetylglucosamine mutase (BtPAGM), UDP-N-acetylglucosamine pyrophosphorylase (BtUAP), and glucosamine-6-phosphate N-acetyltransferase (BtGNA)—using bioinformatic analysis. Quantitative reverse-transcription PCR (RT-qPCR) analyses revealed distinct stage-specific expression patterns for these genes. We used the nanomaterial star polycation (SPc) to deliver gene-specific double-stranded RNA (dsRNA) targeting these genes to fourth instar B. tabaci nymphs, which resulted in significant mortality and developmental defects upon gene silencing. Notably, the fusion dsRNA targeting three genes—BtNAG1, BtNAGK, and BtUAP—achieved approximately 80% nymph mortality, 70% inhibition of adult emergence, and an earlier onset of gene silencing. These findings provide evidence that nanomaterial-assisted delivery of dsRNA can significantly enhance RNAi effects in hemipteran pests and that dsRNA targeting chitin metabolic genes may be an effective strategy for RNAi-based control of B. tabaci. Full article

Background: To evaluate the short-term effects of a dietary supplement containing curcumin, bromelain, glucosamine, chondroitin sulphate, sodium hyaluronate, type II collagen, and vitamin C on symptomatic vitreous floaters (SVFs) following Nd:YAG laser capsulotomy. Methods: Forty eyes with SVFs on the first postoperative day were randomized into a control group (standard topical therapy, n = 20) and a treatment group (oral supplement plus standard therapy, n = 20). Outcomes included best-corrected visual acuity (BCVA), contrast sensitivity (CS), and subjective scores from a non-standardized questionnaire on floater perception (QS1), interference with daily activities (QS2), and foreign body sensation (QS3). Objective evaluation was performed using two novel ultrasound-based methods: mean number of vitreous peaks (MVP) from A-scans and mean grey intensity (MGI) from B-scan images processed with ImageJ. Results: At 2 months, the treatment group showed greater improvement in CS (Δ = 0.26 LogCS, CI, 0.14–0.38; p < 0.01), QS1 (Δ = 1.10; 95% CI, 0.60–1.60; p < 0.01), QS2 (Δ = 0.90; 95% CI, 0.40–1.40; p < 0.01), QS3 (Δ = 0.90; 95% CI, 0.44–1.36; p < 0.01), MVP (Δ = 1.10; 95% CI, 0.60–1.60; p < 0.01), and MGI (Δ = 12.89 units; 95% CI, 7.84–17.93; p < 0.01). BCVA was comparable between groups (p = 0.478). Conclusions: Short-term dietary supplementation with vitreous-specific nutrients is well tolerated and associated with improvements in reducing SVFs and foreign body sensations after Nd:YAG capsulotomy and may represent a promising non-invasive therapeutic option. Full article

Agricultural expansion and intensification generally lead to a depletion in soil organic carbon (SOC). While converting cropland to grassland is a recognized strategy for SOC accumulation, the patterns of SOC accumulation under different grassland types and soil conditions remain unclear. This study evaluated the long-term effects of two perennial grasses—alfalfa (a legume) and switchgrass (a non-legume)—on SOC composition, specifically lignin phenols and amino sugars, in non-saline and saline–alkali soils, using a conventional wheat–maize rotation as a control. Our results showed that both alfalfa and switchgrass significantly enhanced SOC content compared to a wheat–maize rotation, but their accumulation pathways differed between non-saline and saline–alkali soils. In non-saline soils, increases in both lignin phenols and amino sugars (muramic acid and glucosamine) were observed under both perennial grasses. In saline–alkali soils, however, the accumulation was primarily driven by glucosamine. While no significant difference was observed in amino sugars content between the two grasses, switchgrass showed significantly higher lignin phenols content than alfalfa under saline–alkali conditions. This indicated that litter quality regulated the accumulation of plant-derived C in saline–alkali environments, but has no significant impact on the accumulation of microbial-derived C. These findings elucidate the divergent mechanisms that drive SOC sequestration following cropland-to-grassland conversion in contrasting non-saline and saline–alkali soils, highlight the dominant role of microbial processes in SOC accumulation following such conversion. Full article

The identification and quantification of chitinolytic activity in microorganisms is critical for advancing biological control strategies against arthropod pests and fungal pathogens. However, current laboratory methods designed for fast detection of chitinolytic microorganisms are often time-consuming, produce low-quality results and lack sensitivity. Here, we report the development of a novel fluorogenic culture medium incorporating a chemically modified chitinase substrate, N-fluoresceyl poly-D-glucosamine, which allows for a highly sensitive chitinase assay, enabling both qualitative and quantitative fluorescent detection of chitinase activity in situ. This substrate is synthesized through covalent conjugation of poly-D-glucosamine with fluorescein isothiocyanate under alkaline conditions, resulting in an insoluble polymer that becomes fluorescent upon enzymatic hydrolysis by chitinases. When supplemented with culture media, the modified fluorogenic substrate serves as the sole carbon source, selectively supporting the growth of chitinolytic microorganisms. Enzymatic activity is visualized under longwave UV light and can be quantitatively measured via spectrophotometric (493 nm) or fluorometric (530 nm) methods. Validation using characterized entomopathogenic chitinolytic strains of the fungi Aspergillus flavus, Beauveria bassiana, and Metarhizium anisopliae demonstrated a detection sensitivity that was at least three orders of magnitude greater than that of conventional methods. In contrast, the non-chitinolytic fungi Penicillium notatum and Fusarium venenatum presented no detectable fluorescent signals. This fluorogenic medium provides a rapid, cost-effective, and highly sensitive tool for screening chitinolytic microorganisms with potential applications in agriculture, veterinary parasitology, and environmental microbiology. Full article

A novel bacterial strain was isolated from the roots of Suaeda japonica, a halophytic plant inhabiting tidal zones. Phylogenetic, genomic, and phenotypic analyses identified the isolate as a novel species within the genus Paraburkholderia, for which the name Paraburkholderia suaedae sp. nov. is proposed. The strain exhibits multiple plant growth-promoting traits, including the production of 1-aminocyclopropane-1-carboxylic acid, indole-3-acetic acid, and siderophore, along with the ability to fix nitrogen and solubilize phosphate. Genomic analysis revealed genes associated with enhanced root surface adhesion and rhizosphere survival, such as those involved in thiamine biosynthesis and transport, and biofilm formation via poly-β-1,6-N-acetyl-D-glucosamine (PGA) synthesis. These features suggest the strain’s potential for persistent colonization and beneficial interaction with host plants. Although its direct impact on plant growth has not yet been experimentally validated, the genetic and biochemical evidence supports its potential application in agriculture. The objective of this study was to conduct a polyphasic taxonomic characterization of a novel strain DGU8^T isolated from the roots of the halophyte Suaeda japonica, and to assess its potential as a plant growth-promoting agent, particularly its tolerance to drought-related osmotic stress. Full article

Background: Skin aging is influenced by intrinsic factors such as genetics and cellular decline, and extrinsic factors including UV exposure, pollution, and lifestyle. Cosmetic or over-the-counter retinoids, particularly retinal (retinaldehyde), have shown strong efficacy in reducing photoaging signs—such as fine lines, wrinkles, and pigmentation—while offering improved tolerability compared to prescription-based retinoids like all-trans retinoic acid. However, their instability in formulations and limited bioavailability when applied topically remain major challenges. Objective: This exploratory study aimed to assess the efficacy and safety of a novel mix-activated anhydrous 0.1% retinal concentrate formulated also with hydrophilic active ingredients—N-acetyl glucosamine, niacinamide, ascorbic acid, and alpha-glucan oligosaccharide—in improving signs of skin aging over six weeks. Methods: A prospective, single-center study was conducted with 27 healthy adults (24 female and 3 male, aged 40–69 years, 21 with skin phototype III and 6 with phototype II) exhibiting visible signs of photoaging. Participants applied the retinal concentrate once daily, mixed in a 1:2 ratio with a moisturizer before application. Objective skin parameters, including pigmentation, fine lines, wrinkles, texture, volume, and pore visibility, were assessed using the Antera 3D imaging system at baseline and after six weeks. A self-evaluation questionnaire was completed at week six. Statistical significance was determined using the Wilcoxon signed-rank test (p < 0.05) and was corrected for multiple analyses. Results: Significant improvements were observed across all parameters: pigmentation (−12%, p < 0.0001), fine lines (−14%, p < 0.0001), wrinkle depth (−5%, p = 0.0045), skin texture (+12%, p < 0.0001), volume irregularities (−15%, p < 0.0001), and pore visibility (−24%, p < 0.0001). No significant change in redness was detected (p = 0.6664), indicating a good tolerability to the test product. Self-assessments reflected high user satisfaction: 81% reported improved skin appearance, 43% noted reduced need for makeup use, and 40% observed visible improvements already within two weeks. Conclusions: The anhydrous 0.1% retinal concentrate with hydrophilic actives significantly improved clinical signs of photoaging without causing irritation. The innovative mix-activated formulation stabilizes sensitive ingredients and enhances their efficacy, offering a novel, active, and well-tolerated approach to anti-aging skincare. Full article

Hydrogels based on poly (methacrylic acid), carboxymethyl cellulose, and nanocellulose fibers were successfully synthesized, characterized, and tested as topical carriers for the controlled release of hydrophobic resveratrol and hydrophilic acetyl glucosamine, active substances used in skin protection. Carrier composition was confirmed by Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) revealed the pore size variations with alterations in the neutralization degree of methacrylic acid and changes in the pore-wall roughness caused by different mass fractions of nanocellulose. The neutralization degree of methacrylic acid had a substantial impact on the swelling behaviour, while only a slight change in swelling was caused by various contents of nanocellulose in hydrogels. Mechanical properties of the hydrogels accessed by compressive strength measurement at various percentages of strain were improved by the addition of nanocellulose. Hydrogels containing 0.5% nanocellulose achieved the highest compressive strength. The neutralization of methacrylic acid reduced the mechanical properties. Hydrogels with optimal properties showed outstanding potential in encapsulation, and controlled the simultaneous release of resveratrol and N-acetyl glucosamine. The different nature of the active compounds, however, affected the release kinetics and mechanism, as confirmed by the Korsmeyer–Peppas model. Full article

Hypocrellin A (HA), a photodynamic perylenequinone pigment from Shiraia fruiting bodies, functions as an efficient photosensitizer for clinical photodynamic therapy. Glucose-6-phosphate dehydrogenase (G6PDH), the rate-limiting enzyme of the pentose phosphate pathway (PPP), governs carbon flux into NADPH production. This study elucidates G6PDH’s regulatory role in HA biosynthesis in Shiraia sp. S9. Bamboo polysaccharide (BPS) elicitation (100 mg/L) significantly enhanced HA production to 428.1 mg/L, 1.6-fold higher than controls after 5 days. We cloned the G6PDH gene and demonstrated that BPS upregulated its expression and activity, concomitant with increased reactive oxygen species (ROS; H₂O₂ and O₂^•−) and nitric oxide (NO) generation. ROS production was mediated by NADPH oxidase induction, while NO generation was attributed to elevated nitric oxide synthase and nitrate reductase activities. Critically, the G6PDH inhibitor glucosamine (1.0 mM) suppressed both H₂O₂ and NO production. These ROS/NO signals upregulated key HA biosynthetic (PKS, Omef) and transport (MFS) genes. Our findings establish G6PDH as a central regulator of BPS-induced HA biosynthesis via ROS/NO signaling, revealing novel metabolic crosstalk between the PPP and fungal perylenequinone biosynthesis. This work presents BPS elicitation as a biotechnological strategy for scalable HA production in Shiraia mycelium cultures. Full article