内容: The traditional nutritional and medical hemp (Cannabis sativa L.) seed protein were explored for the discovery and directional preparation of new xanthine oxidase inhibitory (XOI) peptides by structure-based virtual screening, compound synthesis, in vitro bioassay and proteolysis. Six subtypes of hemp seed edestin and albumin were in silico hydrolyzed by 29 proteases, and 192 encrypted bioactive peptides were screened out. Six peptides showed to be XOI peptides, of which four (about 67%) were released by elastase hydrolysis. The peptide DDNPRRFY displayed the highest XOI activity (IC50 = (2.10 ± 0.06) mg/mL), acting as a mixed inhibitor. The pancreatic elastase directionally prepared XOI hemp seed protein hydrolysates, from which 6 high-abundance XOI peptides encrypted 3 virtually-screened ones including the DDNPRRFY. The novel outstanding hemp seed protein-derived XOI peptides and their virtual screening and directed preparation methods provide a promising and applicable approach to conveniently and efficiently explore food-derived bioactive peptides.

内容: Gastric ulcer is a widespread disease caused by various etiologies. Dendrobium officinale flowers exert several health benefits owing to their rich flavonoid content. In this study, protective effects and possible action mechanisms of D. officinale flowers’ flavonoid enriched extract (DOFF) were assessed against gastric ulcer. The result of sodium nitrite-aluminum nitrate colorimetry showed that 52.34% of the total extractive was flavonoid, and ultra-high performance liquid chromatography time of flight mass spectrometer (UPLC-Q-TOF/MS) revealed the presence of 28 components in DOFF of which 14 belonged to flavonoids. In addition, in vivo assay revealed DOFF potential in reducing the formation of ethanol-induced gastric mucosal lesions, with drop-in ulcer index from 64.33 ± 8.76 to 32.00 ± 4.47. Similar results were revealed in human gastric mucosal epithelia cells, with cells viability to increase from 27.2% to 61.6% post DOFF administration. To analyzed the protect effect of DOFF, we used Western blotting and immunofluorometric assay to revealed the expression levels of key proteins in cell pathways. The results showed that DOFF (320 μg/mL) could increase the level of oxidation marker protein (HO-1), apoptosis regulatory protein (Bcl-2) and autophagy marker (LC3β) by 50.84%, 43.85%, and 59.21% compared with ethanol-treated group respectively. Further analyzed of the mitochondrial activity and apoptosis pathway, we found that DOFF appeared to mitigate against ethanol-induced gastric mucosal injury via AMPK/mTOR/ULK1 and PI3K/AKT autophagy signaling pathways.

内容: Intestinal immune homeostasis plays a critical role in the pathogenesis of food allergy. However, the association between intestinal microenvironment factors and food allergy severity is not well studied. In this study, we established a gluten allergy (GA) BALB/c mouse model and revealed the intestinal luminal factor-mediated alterations in phenotypes and endotypes of GA, combined with untargeted metabolomic profiling of the colonic contents. Our results showed that gluten sensitization induced severe allergic responses in BALB/c mice, characterized by exacerbated clinical allergic and diarrheal symptoms, increased histamine, elevated gluten-specific immunoglobulin (Ig)E and IgG2a levels, and increased mast cell degranulation. In response to GA, T-cell balance was disrupted, with aberrant production of interleukin (IL)-4, interferon (IFN)-γ, IL-10, and IL-2 in the spleen. GA led to a disrupted intestinal microenvironment homeostasis, including increased pH and water content, impaired intestinal antioxidant capacity and epithelial barrier function, decreased short-chain fatty acid production, and microbial dysbiosis, which was strongly correlated with GA severity. By metabolomic profiling, we found 29 differential expressed metabolites (DEMs) associated with GA, with 9 down-regulated and 20 up-regulated. A total of 11 out of all DEMs were classified into dipeptides, and 10 of them were up-regulated in the GA mice. Pathway enrichment analysis showed that most of the DEMs were enriched into the bile secretion metabolic route.

内容: Oyster, as a common aquatic food, play an important role in shellfish allergy. In this study, 2 tropomyosin (TM) isoforms TM-α and TM-β (TM-α/-β) in Alectryonella plicatula were identified. The sequences of 852 bp encoding 284 amino acids of TM-α/-β and 2 recombinant proteins were obtained, respectively. There were 12 amino acid differences between TM-α/-β. The results of immunological experiments indicated that TM-β had stronger immunobinding activity and immunoreactivity than those of TM-α. Structural analysis showed that TM-β had more α-helix and higher surface hydrophobicity than TM-α. Sequences and epitopes alignment with shellfish TMs revealed that amino acids of TM-β were more frequently recognized as IgE epitopes in other shellfish TMs than TM-α. Differences in structure and sequence account for the higher immunological activity of TM-β compared to TM-α. These findings provide a theoretical basis for enriching the understanding of shellfish TM and accurate diagnosis of allergic components.

内容: Prenatal overweight/obesity (OW/OB) can alter colostrum lipid patterns, thereby affecting the lipid metabolism and even the cognitive and healthy development of infants. However, studies on changes in colostrum lipids in the context of OW/OB are limited, particularly for glycerides and polar lipids. Therefore, this study investigated the influence of maternal prenatal weight on colostrum in lipid subclasses and molecular species. The concentration of triacylglycerols (TAGs) in the colostrum of the OW/OB group (35 894.43 mg/L) was higher than that of the normal weight (NW) group (26 639.20 mg/L), suggesting that colostrum from OW/OB mothers could provide more energy to their infants. Further analysis of the fatty acid composition of TAGs revealed that elevated maternal body weight enhanced the concentration of TAGs containing saturated or n-6 fatty acids and shortened the carbon number of TAGs. Docosahexaenoic acid (DHA)/arachidonic acid (AA)/choline-containing lipids, such as DHA-containing TAGs, AA/DHA-containing phosphatidylethanolamine, and choline-containing phospholipids, were present in higher levels in the colostrum of OW/OB mothers than NW mothers. However, the concentrations of palmitic acid-containing TAGs, linoleic acid-containing TAGs, dihomo-γ-linolenic acid-containing TAGs, and polar lipids and the ratio of TAGs containing n-6 fatty acid/n-3 fatty acid were significantly higher in the colostrum of OW/OB mothers than in that of NW mothers. The fatty acid composition and sphingoid bases of sphingolipids were also altered due to elevated body weight. In conclusion, OW/OB affects colostrum lipids with respect to composition, concentration, and percentage. Although the colostrum of healthy OW/OB mothers can provide sufficient DHA/AA/choline-containing lipids to their infants, normalization of body weight and fat reserves should be considered as a strategy for high-quality human milk lipids.