Sinan Chen

As an edible and medicinal fungus, Auricularia auricula contains polysaccharides (AAPs) as its primary bioactive components. The molecular weight (Mw) of these macromolecules is recognized as a critical determinant of their bioavailability and physiological effects. However, systematic comparative studies on the respiratory protective effects of AAPs with Mws are still limited. In this study, two AAPs with distinct Mws (1554 kDa and 31 kDa) were prepared and characterized, and their antitussive, expectorant, and anti-asthmatic activities were evaluated. The results revealed that the two AAPs exhibited different monosaccharide compositions. Compared with AAPs-H (1554 kDa), AAPs-L (31 kDa) showed superior in vitro antioxidant activity, better solubility, and lower viscosity. Furthermore, AAPs-L improved redox profiles (SOD, GSH-Px, MDA) and reduced substance P release to 2.17 pg/mL, thereby attenuating the cascade of pro-inflammatory mediators. Consequently, mice treated with 200 mg/kg BW AAPs-L exhibited a significant reduction in cough frequency and prolonged cough incubation period. In contrast, AAPs-H, with its higher Mw and mannose content (50.24%), exerted unique anti-asthmatic effects by restoring Th1/Th2 immune balance, modulating the NF-κB signaling pathway, and reshaping the gut microbiota, as evidenced by an increased abundance of Cryptobacteroides sp900546395. And both AAPs promoted phenol red excretion, indicating expectorant effects. This study comprehensively evaluated and compared the differential protective effects of AAPs with distinct Mws on the respiratory system in mice, providing a new perspective for the functional food application and comprehensive utilization of Mw-tailored AAPs.

Mannatide, a glycopeptide derived from the fermentation of α-hemolytic Streptococcus, exhibits diverse immunomodulatory activity. However, clinical evidence regarding its efficacy in colitis remains limited, and its underlying mechanisms are poorly understood. In this study, mannatide was produced via submerged fermentation of α-hemolytic Streptococcus, yielding a concentration of 0.15 mg/mL in the fermentation broth and a molecular weight of 57,401 Da as determined by HPGPC-RID. The effects of mannatide on DSS-induced colitis in mice were also evaluated. The results demonstrated that mannatide alleviated clinical symptoms including weight loss and colon shortening, mitigated pathological damage such as mucosal epithelial disruption and inflammatory cell infiltration, and reduced histological scores from 4.56 to below 2. Additionally, it improved redox profiles by increasing SOD activity to 1.8 times that of the model group at a dosage of 50 mg/kg/BW. Mechanistically, mannatide mediated PI3K/Akt, which was involved in the pathogenesis of colitis in mice through multidirectional transcriptional regulation, including mediating the NF-κB pathway to reduce inflammation, regulating Th17/Treg immune homeostasis, and engaging Akt/eNOS for intestinal mucosal protection. Furthermore, mannatide at 50 mg/kg/BW upregulated the abundance of CAG-485, Muribaculum, and Alistipes-A, affecting P221-PWY, FAO-PWY, REDCITCYC, and PWY-6590 and other colitis-related metabolic pathways via altering gut microbiota composition, ultimately alleviating colitis in mice. Thus, this study provided a foundation for utilizing α-hemolytic Streptococcus and mannatide, as well as offered mechanistic insights for optimizing colitis treatment.

L-ascorbic acid (vitamin C, VC), an essential nutrient obtained from the diet to maintain various vital signs for the human body, is a crucial indicator of food quality and nutritional value. Herein, high-performance liquid chromatography with electrochemical detection (HPLC-ECD) was developed and validated with the advantages of higher sensitivity, simpler operation processes, and more rapid detection in measuring VC levels in honey samples when compared with the common methods (titration, spectrophotometric, and HPLC-DAD methods). The results of the HPLC-ECD methodological validation showed that the limit of detection (LOD) was 0.0043 µg mL⁻¹; the relative standard deviations (RSDs) of the intra- and inter-day values were between 2.51% and 5.15%, and the regression coefficient was >0.999 in the linear range of 0.1 to 20 µg mL⁻¹. The validated HPLC-ECD method was also successfully utilized to evaluate the VC levels in different varieties of honey samples with various storage durations as well as in fruit and biological samples. This study provided a perspective for the further accurate determination of VC content in food and biological samples.

Colitis is an inflammatory disease that results from the overactivation of effector immune cells, producing a high quantity of pro-inflammatory cytokines. Our study aimed to explore whether buckwheat (F. esculentum) bee pollen extract (FBPE) could inhibit the progression of dextran sulfate sodium (DSS)-induced colitis via regulating immune function. We isolated and identified six main phenolic compounds of FBPE such as luteolin (9.46 mg/g) by column chromatography, HPLC-DAD, ESI-MS and NMR spectroscopy, then assessed their effects on colonic mucosal injury by clinical symptoms, histomorphology and immunohistochemistry examinations. The results showed that FBPE at 25.2 g/kg body weight (g/kg BW) changed the clinical symptoms of colitis, the ICAM-1 expression in colon, the activity of related inflammatory mediators in colon tissue and helped restore the immune system. Compared with the model group (40.28%), the CD4 positivity was significantly reduced in the HD (High-dose group: 25.2 g FBPE/kg BW/day) group (20.45%). Administration of 25.2 g/kg BW of FBPE decreased the IFN-γ, TNF-α and IL-4 levels, while enhancing the IL-10 level, and significantly inhibited the abnormally decreased IgG (Model: 13.25 mg/mL, HD: 14.06 mg/mL), showing a reversal effect on the Th1/Th2 levels in colitis. These findings suggested that FBPE at 25.2 g/kg BW had the effects of alleviating colitis and immunomodulation, which can help in the development of safe and effective immune therapy.

Actinidia arguta pollen owns abundant nutrients, such as vitamins, polyphenols, etc., however, little research on its antioxidant ability and biological function was conducted. In this study, we observed A. arguta pollen spore structure by SEM (Scanning electron microscope), analyzed the phenolic composition of A. arguta pollen extract (AAPE) obtained by four extraction methods (A: ultrasound‐assisted extraction with water, B: heat reflux extraction with water, C: ultrasound‐assisted extraction with ethanol, and D: heat reflux extraction with ethanol). Total phenolic content, total flavonoid content, antioxidant activities (ferric reducing/antioxidant power [FRAP], chelating activity, and DPPH^⋅scavenging activity) were also determined. Finally, we investigated its protective effect on DNA and lymphocytes damage response to oxidative stress. The results showed that the morphology of A. arguta pollen was similar to other pollen of the genus A. Lindl., but differs from them slightly in the specific morphology indicators. What is more, AAPE obtained by different extraction methods exhibited a protective effect against DNA oxidative damage, they also possessed a strong cytoprotection effect on mouse lymphocytes, especially the extraction obtained by method C, which had the highest total phenolic content (15.05 ± 0.34 mg GAE/g), strong ferrous ion‐chelating ability (0.37 ± 0.023 mg Na₂EDTA/g), DPPH^⋅ scavenging activity (IC₅₀ = 0.14 ± 0.04 mg/ml), and FRAP (7.13 ± 0.33 mg Trolox/g). This paper provided a new edible natural antioxidant for human which will protect us from oxidative stress. Practical applications This study was the first to report the morphology of Actinidia arguta pollen by SEM analysis, and studied the effects of different extraction methods on antioxidant activities and cytoprotective effect of A. arguta pollen extract. We believed that our research makes a significant contribution to the literature, because the results of this research provide a reference for the development of a new edible natural antioxidant.

Schisandrachinensisbee pollen has been used as a health food in China for centuries; however, its bioactive constituents and functions are not very clear. In this study, we investigated the phenolic compounds of Schisandrachinensisbee pollen extract (SCPE) by UHPLC-Q-Orbitrap-HRMS/HPLC-DAD-ECD and its prevention from nonalcoholic fatty liver disease (NAFLD) and modulation of gut microbiota in high fat diet induced obese C57BL/6 mice. The results showed that 12 phenolic compounds were identified in SCPE, and naringenin, rutin and chrysin were the main constituents. The content of naringenin reached 1.89 mg/g, and total phenolic content (TPC) of SCPE were 101.83 mg GA/g. After obese mice were administrated with SCPE at 7.86 and 15.72 g/kg BW for 8 weeks, body weight gains were reduced by 18.23% and 19.37%. SCPE could decrease fasting blood glucose, cut down the lipid accumulation in serum and liver, lessen oxidative injury and inflammation in obesity mice. Moreover, SCPE could effectively inhibit the formation of NAFLD by inhibition of LXR-α, SREBP-1c and FAS genes expression, and modulate the structural alteration of gut microbiota in obesity mice. These findings suggested that SCPE could attenuate the features of the metabolism syndrome in obesity mice, which can be used to prevent obesity and NAFLD of human beings.