內(nèi)容: The aim of this study was to investigate whether punicalagin (PU) could prevent obesity-related cardiac dysfunction by promoting DNA demethylation, and to explore its possible mechanism. C57BL/6J mice were fed with standard diet, high-fat diet (HFD), HFD supplemented with resveratrol, low-dose PU (LPU) and high-dose PU (HPU) for 8 weeks. Compared with HFD group, body weight was significantly lower in PU treatment groups, number of cardiomyocytes and the protein level of myosin heavy chain 7B were significantly higher in PU treatment groups. Levels of 5-hydroxymethylcytosine and 5-formylcytosine were significantly lower in HFD group than in other groups. Compared with the HFD group, the protein level of ten-eleven translocation enzyme (TET) 2 was significantly higher in PU treatment groups, p-AMP-activated protein kinase (AMPK) was significantly higher in LPU group. Levels of total antioxidant capacity and the protein levels of complexes II/III/V, oxoglutarate dehydrogenase, succinate dehydrogenase B and fumarate hydrolase were significantly lower in HFD group than PU treatment group. The ratio of (succinic acid + fumaric acid)/α-ketoglutarate was significantly higher in HFD group than other groups. In conclusion, PU up-regulated TETs enzyme activities and TET2 protein stability through alleviating mitochondrial dysfunction and activating AMPK, so as to promote DNA demethylation, thus preventing obesity-related cardiac dysfunction.

內(nèi)容: Our previous study has revealed that procyanidin A1 (A1) and its simulated digestive product (D-A1) can alleviate acrylamide (ACR)-induced intestine cell damage. However, the underlying mechanism remains unknown. In this study, we elucidated the molecular mechanism for A1 and D-A1 to alleviate ACR-stimulated IPEC-J2 cell damage. ACR slightly activated nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and its target genes, but this activation could not reduce intestine cell damage. A1 and D-A1 could alleviate ACR-induced cell damage, but the effect was abrogated in cells transiently transfected with Nrf2 small interfering RNA (siRNA). Further investigation confirmed that A1 and D-A1 interacted with Kelch-like ECH-associated protein 1 (Keap1), which boosted the stabilization of Nrf2, subsequently promoted the translocation of Nrf2 into the nucleus, and further increased the expression of antioxidant proteins, thereby inhibiting glutathione (GSH) consumption, maintaining redox balance and eventually alleviating ACR-induced cell damage. Importantly, there was no difference between A1 and D-A1 treated groups, indicating that A1 can tolerate gastrointestinal digestion and may be a potential compound to limit the toxicity of ACR.

內(nèi)容: This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism. Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion (ICSE) combined with enzymatic hydrolysis, followed by chelation reaction to prepare rabbit bone peptide-calcium chelate (RBCP-Ca). The chelating sites were further analyzed by liquid chromatography-tandem mass (LC-MS/MS) spectrometry while the chelating mechanism and binding modes were investigated. The structural characterization revealed that RBCP successfully chelated with calcium ions. Furthermore, LC-MS/MS analysis indicated that the binding sites included both acidic amino acids (Asp and Glu) and basic amino acids (Lys and Arg). Interestingly, three binding modes, namely Inter-Linking, Loop-Linking and Mono-Linking were for the first time found, while Inter-Linking mode accounted for the highest proportion (75.1%), suggesting that chelation of calcium ions frequently occurred between two peptides. Overall, this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.

內(nèi)容: Diarrhea has become the leading cause of illness and death among infants and young children in developing countries. Clinically, patients with diarrhea showed damaged intestinal epithelial villi, usually accompanied by lactase deficiency. In this study, we evaluated the therapeutic effects of lactose-free milk powder on rats and children with diarrhea. Antibiotic-associated diarrhea (AAD) model was established by gavage with antibiotic mixture in SD rats, followed by administration of milk powder containing lactose or not. The results showed that lactose-free milk powder ameliorated AAD-related diarrhea symptoms, and accelerated the recovery from diarrhea. And 16S sequencing results indicated lactose-free milk powder contributed to increase the α- and β-diversity of intestinal flora, and restore the intestinal microbiota disorder. In conclusion, our data demonstrate that lactose-free milk powder could alleviate diarrhea by restoring gut microbiota and intestinal barrier function.

內(nèi)容: The study evaluated the stability of an oligopeptide (Lys-Arg-Gln-Lys-Tyr-Asp, KRQKYD) and its transport mechanism by simulating gastrointestinal digestion and a model of human intestinal Caco-2 monolayer cells in vitro. In this study, the effects of environmental factors (temperature, pH and NaCl concentration) and simulated gastrointestinal digestion on the stability of KRQKYD were evaluated by indicators of the levels of alanine transaminase (ALT), aspartate transaminase (AST) and malondialdehyde (MDA) in an alcohol-induced hepatocyte injury model. The results showed that KRQKYD still maintained satisfactory hepatocyte-protective activity after treatment with different temperatures (20?80 °C), pH (3.0?9.0), NaCl concentration (1%?7%) and simulated gastrointestinal digestion, which indicated that KRQKYD showed good stability to environmental factors and simulated gastrointestinal digestion. Furthermore, the intact KRQKYD could be absorbed in a model of Caco-2 monolayer cells with a Papp value of (9.70 ± 0.53) × 10?7 cm/s. Pretreatment with an energy inhibitor (sodium azide), a competitive peptide transporter inhibitor (Gly-Pro) and a transcytosis inhibitor wortmannin did not decrease the level of transepithelial KRQKYD transport, indicating that the transport mechanism of KRQKYD was not associated with energy dependent, vector mediated and endocytosis. The tight junction disruptor cytochalasin D significantly increased the level of transepithelial KRQKYD transport (P < 0.05), suggesting that intact KRQKYD was absorbed by paracellular transport.

內(nèi)容: Golden-flower fungus, the only dominant microorganism determining the Fu-brick tea quality through fermentation and the important microbe in Liupao tea, is considered a potential probiotic fungus based on its anti-obesity effect. However, the classification of golden-flower fungi is still controversial; the anti-obesity effect of golden-flower fungus polysaccharides remains unknown. In this study, we identify a golden-flower strain as Aspergillus cristatus based on morphological characteristics and multigene phylogeny analysis, which resolves the controversy of classification. Moreover, we find A. cristatus polysaccharides (ACPS) attenuate obesity in rats. ACPS modulate gut bacterial composition, in which Akkermansia, Akkermansia muciniphila, Bacteroides, Romboutsia, Blautia, and Desulfovibrio are considered the core microbes regulated by ACPS. ACPS increase fecal total short-chain fatty acid content and serum, hepatic, and fecal total bile acid content. Furthermore, ACPS-induced gut microbiota alteration plays a causal role in the protection from obesity, according to a fecal transplantation experiment. Thus, ACPS ameliorate obesity by regulating gut microbiota and gut microbiota-related metabolites.

內(nèi)容: Soluble receptor for advanced glycation end products (sRAGE) acts as a decoy sequestering of RAGE ligands, thus preventing the activation of the ligand-RAGE axis linking human diseases. However, the molecular mechanisms underlying sRAGE remain unclear. In this study, THP-1 monocytes were cultured in normal glucose (NG, 5.5 mmol/L) and high glucose (HG, 15 mmol/L) to investigate the effects of diabetes-relevant glucose concentrations on sRAGE and interleukin-1β (IL-1β) secretion. The modulatory effects of epigallocatechin gallate (EGCG) in response to HG challenge were also evaluated. HG enhanced intracellular reactive oxygen species (ROS) generation and RAGE expression. The secretion of sRAGE, including esRAGE and cRAGE, was reduced under HG conditions, together with the downregulation of a disintegrin and metallopeptidase 10 (ADAM10) and nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation. Mechanistically, the HG effects were counteracted by siRAGE and exacerbated by siNrf2. Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding. Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors. Under HG conditions, the treatment of EGCG reduced ROS generation and RAGE activation. EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway. EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE, thereby reducing IL-1β release.

內(nèi)容: Type 2 diabetes mellitus (T2DM) is a metabolic disease caused by a glycolipid metabolism disorder and islet β-cell dysfunction. SCP-80-I is a biologically active water-soluble polysaccharide isolated from sweet corncob, an agricultural byproduct. The hypoglycemic effects of SCP-80-I on T2DM mice and its mechanisms were investigated in this study. SCP-80-I was found to significantly reduce blood glucose and lipid deposition levels in T2DM mice, as well as decrease serum leptin and increase adiponectin secretion. Interestingly, real time-polymerase chain reaction (RT-PCR) and Western blotting results revealed that SCP-80-I could regulate the expression of several glycolipid metabolisms and insulin secretion genes and proteins, including 5’-AMP-activated protein kinase (AMPK), carnitine palmitoyltransferase I (CPT1), and acetyl coenzyme A carboxylase (ACC) in the liver and AMPK, sirtuin 1 (Sirt1), peroxisome proliferator-activated receptorycoactivator-1 (PGC-1α), and uncoupling protein 2 (UCP2) in the pancreas. To have a hypoglycemic effect, SCP-80-I regulated glycolipid metabolism and islet cell function in the liver by regulating the AMPK/ACC/CPT1 signaling pathway and the AMPK/Sirt1/PGC-1α and AMPK/Sirt1/UCP2 signaling pathways. These findings improve our understanding of polysaccharides derived from sweet corncob and the use of SCP-80-I in the production of hypoglycemic foods.

內(nèi)容: Slightly acidic electrolyzed water (SAEW) has proven to be an efficient and novel sanitizer in food and agriculture field. This study assessed the efficacy of SAEW (30 mg/L) at 40 °C on the inactivation of foodborne pathogens and detachment of multi-resistant Staphylococcus aureus (MRSA) biofilm. Furthermore, the underlying mechanism of MRSA biofilm under heated SAEW at 40 °C treatment on metabolic profiles was investigated. The results showed that the heated SAEW at 40 °C significantly effectively against foodborne pathogens of 1.96–7.56 (lg (CFU/g)) reduction in pork, chicken, spinach, and lettuce. The heated SAEW at 40 °C treatment significantly reduced MRSA biofilm cells by 2.41 (lg (CFU/cm2)). The synergistic effect of SAEW treatment showed intense anti-biofilm activity in decreasing cell density and impairing biofilm cell membranes. Global metabolic response of MRSA biofilms, treated by SAEW at 40 °C, revealed the alterations of intracellular metabolites, including amino acids, organic acid, fatty acid, and lipid. Moreover, signaling pathways involved in amino acid metabolism, energy metabolism, nucleotide synthesis, carbohydrate metabolites, and lipid biosynthesis were functionally disrupted by the SAEW at 40 °C treatment. As per our knowledge, this is the first research to uncover the potential mechanism of heated SAEW treatment against MRSA biofilm on food contact surface.

內(nèi)容: The nutrient digestion, absorption and biological activity of bee pollen may be limited due to the complex pollen wall. Here, the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated, and their antioxidant activities and in vitro digestion were explored in this study. Results showed that the content of nutrients in bee pollen increased after wall disruption. Among them, fat content increased by 22.55%–8.31%, protein content increased by 0.54%–4.91%, starch content increased by 36.31%–48.64%, soluble sugar content increased by 20.57%–29.67%, total phenolic acid content increased by 11.73%–86.98% and total flavonoids content increased by 14.29%–24.79%. At the same time, the antioxidant activity increased by 14.84%–46.00%. Furthermore, the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion, and easier to be absorbed because of their higher bioaccessibility. Antioxidant activities during in vitro digestion were also improved in wall-disruption bee pollen. These findings provide evidence that bee pollen wall disruption was suggested, thus, it is more conducive to exerting the value of bee pollen in functional foods.