Yongmei Lyu

This study investigated the protective effects of alfalfa polysaccharide fraction II (APS‐II) on immunosuppression induced by cyclophosphamide (CTX) in mice. APS‐II was extracted using ultrasound‐assisted enzymatic extraction method and purified by DEAE‐52 cellulose chromatography. Its structural characteristics, including molecular weight (Mw), monosaccharide composition, and thermal stability, were analyzed. A CTX‐induced immunosuppressed mouse model was established to evaluate the effects of APS‐II on immune organ indices, serum cytokines, antioxidant indicators in liver and spleen tissues, and intestinal microbiota. Results showed that APS‐II, with main Mw of 28.05 kDa, consisted of glucose, galactose, mannose, arabinose, glucuronic acid, and rhamnose in the molar ratio of 8.04:1.22:1.18:0.92:1:0.06. Treatment with medium and high doses of APS‐II significantly restored thymus and spleen indices ( p  < 0.05), increased serum cytokine levels of interleukin‐2 (IL‐2), interleukin‐1 beta (IL‐1β), and interferon‐gamma (IFN‐γ) ( p  < 0.05), and ameliorated spleen and thymus histopathology. Antioxidant parameters of total antioxidant capacity (T‐AOC), catalase (CAT), and glutathione (GSH) were elevated, and malondialdehyde (MDA) was reduced, reaching significance at the high dose ( p  < 0.05). Additionally, APS‐II reshaped the gut microbiota by increasing Bacteroidota abundance and reducing the Firmicutes/Bacteroidota ratio ( p  < 0.05), enriching Muribaculaceae and Lactobacillus ( p  < 0.01), while decreasing potentially pathogenic Rikenellaceae. In conclusion, APS‐II provides significant protection against CTX‐induced immunosuppression and holds promise as a functional food ingredient for immune health. Practical Applications: Alfalfa polysaccharide fraction II (APS‐II) exerts a protective effect on mice with CTX‐induced immunosuppression, laying the scientific foundation for its development as an immunomodulatory ingredient in functional foods and dietary supplements.

This study focused on the inhibitory effects of wheat bran feruloyl oligosaccharides (FOs) on the formation of AGEs in three bovine serum albumin (BSA)-based non-enzymatic glycation models, namely BSA-fructose, BSA-methylglyoxal (MGO), and BSA-glyoxal (GO). In the BSA-fructose model, FOs at 0.25 mg/mL achieved a 62% inhibition rate of fructosamine, equivalent to approximately 78% of the activity of the positive control aminoguanidine (AG), and reduced fluorescent AGEs by over 50% on day 12. Additionally, FOs suppressed the accumulation of α-dicarbonyl compounds, key intermediates in the glycation pathway. In the BSA-MGO and BSA-GO system, the decreased fluorescence intensity of tryptophan residues indicated that FOs bound to BSA, inducing conformational changes in the protein microenvironment; this binding also inhibited protein carbonyl formation and the loss of thiol groups, thereby modulating the protein glycation process. Compared with their precursors (ferulic acid, FA; xylooligosaccharides, XOS), FOs exhibited comparable or even superior inhibitory activity against specific AGE subtypes, suggesting a synergistic effect between the feruloyl and oligosaccharide moieties. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that FOs reduced the band intensity of 90 kDa AGEs in the glycation system, indicating the inhibition of protein-fructose cross-linking. Fluorescence spectroscopy confirmed that FOs dynamically quenched BSA with a single binding site, and thermodynamic calculations demonstrated that the binding was spontaneous (ΔG < 0), primarily driven by hydrogen bonds and van der Waals forces (ΔH < 0, ΔS < 0). This study systematically investigated the anti-glycation activities of FOs and their precursors. The findings demonstrate that FOs are promising natural glycation inhibitors and provide important theoretical and experimental support for related research. Furthermore, this study establish a basis for the green and high-value utilization of agricultural by-products like wheat bran.

The objective of this research was to investigate the effects of how feruloyl oligosaccharides (FOs) on the physical properties, antioxidant activity, and antimicrobial efficacy of chitosan‐based (CS) films. Among the tested formulations, the film containing 10% FOs (CS/FOs‐10) demonstrated optimal physical properties, including significant water degradability and excellent extensibility. In vitro antioxidant assays revealed that wheat bran FOs significantly enhanced the overall antioxidant capacity of CS films, with the CS/FOs‐15 film achieving an ABTS radical scavenging rate of 96%. Antimicrobial activity tests on both the film‐forming solution and film surface indicated that the CS/FOs films exhibited substantial antimicrobial efficacy against Escherichia coli and Staphylococcus aureus compared to the blank control. In practical pork preservation applications, the CS/FOs films effectively inhibited microbial growth, delayed spoilage, and extended shelf life. On the basis of the experimental results and economic considerations, the CS/FOs‐10 film demonstrated significant potential for use in meat packaging, providing a scientific foundation for the development of novel, environmentally friendly food packaging materials.

Fermented walnut (FW) meal exhibits antifungal activity against Penicillium victoriae (the fungus responsible for prickly pear spoilage), which is mainly attributed to the synergistic effect of antimicrobial peptides and salicylic acid (SA). This study aimed to investigate the synergistic mechanism between YVVPW (YW-5, the peptide with the highest antifungal activity) and SA against the cell membrane of P. victoriae. Treatment enhanced prickly pear’s rot rate, polyphenol concentration, and superoxide dismutase (SOD) activity by 38.11%, 8.11%, and 48.53%, respectively, while reducing the microbial count by 19.17%. Structural analyses revealed β-sheets as YW-5′s predominant structure (41.18%), which increased to 49.0% during SA interaction. Molecular docking demonstrated YW-5′s stronger binding to β-(1,3)-glucan synthase and membrane protein amino acids via hydrogen bonds, hydrophobic forces, and π-π conjugate interactions. Spectroscopic analyses demonstrated SA’s major role in YW-5 synergy at the interface and polar head region of phospholipids, enhancing lipid chain disorder and the leakage of cell components. Malondialdehyde and SOD levels increased nearly two-fold and six-fold when treated with YW-5/SA, and YW-5 showed a more pronounced effect. Scanning electron and transmission electron microscopy confirmed that SA caused greater damage to spore morphology and cell ultrastructure. These findings support this formulation’s functions as an efficient antifungal substance in fruit storage.

The objective of this study was to determine the optimal extraction conditions for total flavonoids from S. bigelovii using microwave-assisted extraction and to analyze the protective effect of total flavonoids from S. bigelovii on alcoholic liver injury in mice. The optimization of the process conditions for the microwave-assisted extraction of total flavonoids from S. bigelovii was performed using response surface methodology, and an alcohol-induced acute liver injury model in mice was used to investigate the effects of different doses of total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) on the levels and activities of serum alanine aminotransferase kits (ALT), glutamic oxaloacetic transaminase kits (AST), superoxide dismutase kits (SOD), glutathione peroxidase kits (GSH-Px), and malondialdehyde (MDA). We performed hematoxylin–eosin (H&E) staining analysis on pathological sections of mouse liver tissue, and qRT-PCR technology was used to detect the expression levels of the inflammatory factors IL-1 β, IL-6, and TNF-α. The results revealed that the optimal extraction process conditions for total flavonoids in S. bigelovii were a material-to-liquid ratio of 1:30 (g/mL), an ethanol concentration of 60%, an extraction temperature of 50 °C, an ultrasound power of 250 W, and a yield of 5.71 ± 0.28 mg/g. Previous studies have demonstrated that the flavonoids of S. bigelovii can significantly inhibit the levels of ALT and AST in the serum (p < 0.001), reduce MDA levels (p < 0.001), increase the activity of the antioxidant enzymes SOD and GSH-Px (p < 0.001), and inhibit the IL-1 β, IL-6, and TNF-α gene expression levels (p < 0.001) of inflammatory factors. The total flavonoids of S. bigelovii exert a protective effect against alcoholic liver injury by reducing the levels of inflammation, oxidative stress, and lipid peroxidation caused by alcohol. The results of this study lay the foundation for the high-value utilization of S. bigelovii and provide new resources for the development of liver-protective drugs.

Summary: As functional oligosaccharides, feruloyl oligosaccharides (FOs) exhibit the physiological activities of both ferulic acid and oligosaccharides. In this study, FOs were prepared by fermenting wheat bran with the generally recognised as safe (GRAS) bacterium Bacillus amyloliquefaciens IT‐45. On the fourth day of fermentation, the activities of xylanase and cellulase reached 447.67 and 33.41 U/mL, respectively. UV, FTIR, and HPLC were used to characterise the structure properties of wheat bran FOs from B. amyloliquefaciens IT‐45 fermentation. The monosaccharide compositions of FOs were mainly composed of xylose and arabinose. Under the optimal conditions of fermentation time of 4 days, fermentation temperature of 25 °C, initial pH of 6.5 and inoculation amount of 11% (v/v), the maximum yield of FOs in the broth was 0.6397 mM. In vitro antioxidant activity analysis showed that FOs prepared by B. amyloliquefaciens fermentation had good scavenging ability against ABTS, DPPH and hydroxyl radicals, demonstrating the application potential. The results provided a relatively environmentally friendly and food‐safety way to prepare feruloyl oligosaccharides.

Glucosamine (GlcN) is a widely used food supplement. Hence, enormous attention has been concerned with enzymatic production of GlcN owing to its advantage over a chemical approach. In this study, a previously unstudied chitinase gene (MxChi) in the genome of Myxococcus xanthus was cloned, expressed in recombinant soluble form and purified to homogeneity. TLC-, UPLC-, and microplate-reader- based activity tests confirmed MxChi hydrolyzes colloidal chitin to chitobiose as sole product. The optimal catalytic pH and temperature of MxChi was identified as 7.0 and 55 °C, respectively. MxChi exhibited 80% activity after 72 h incubation at 37 °C. The site-directed mutagenesis revealed that the amino acids D323A, D325A, and E327A of MxChi were in the DXDXE catalytic motif of GH18. When coupled with β-N-acetylhexosaminidase (SnHex) and deacetylase (CmCBDA), the enzyme allowed one-pot extraction of GlcN from colloidal chitin and shrimp shell. The optimal condition was 37 °C, pH 8.0, and 1/3/16.5 (MxChi/SnHex/CmCBDA), conducted by orthogonal design for the enzymatic cascades. Under this condition, the yield of GlcN was 26.33 mg from 400 mg shrimp shell. Facile recombinant in E. coli, robust thermostability and pure product herein makes newly discovered chitinase a valuable candidate for the green recycling of chitin rich waste.