Characterization and Mechanism of a Novel Rice Protein Peptide (AHVGMSGEEPE) Calcium Chelate in Enhancing Calcium Absorption in Caco-2 Cells.

Rice protein peptides (RPP) are a potentially valuable source of high-quality calcium chelating properties. However, there is a lack of information regarding the calcium-absorption-promoting effect of RPP and its underlying mechanism. The present study adopted molecular docking methodologies to analyze the 10 most potent peptide segments from RPP. Results revealed that the peptide AHVGMSGEEPE (AHV) displayed optimal calcium binding properties (calcium-chelating capacity 55.69 ± 0.66 mg/g). Quantum chemistry analysis revealed that the AHV peptide effectively binds and forms stable complexes with calcium via the carbonyl oxygen atoms in valine at position 3 and the carbonyl of the C-terminal carboxyl group of glutamate at position 11. The spectral analysis results indicated that AHV may bind to calcium through carboxyl oxygen atoms, resulting in a transition from a smooth surface block-like structure to a dense granular structure. Furthermore, this study demonstrated that the 4 mmol/L AHV-Ca chelate (61.75 ± 13.23 µg/well) significantly increases calcium absorption compared to 1 mM CaCl2 (28.57 ± 8.59 µg/well) in the Caco-2 cell monolayer. In terms of mechanisms, the novel peptide-calcium chelate AHV-Ca derived from RPP exerts a cell-level effect by upregulating the expression of TRPV6 calcium-ion-channel-related genes and proteins (TRPV6 and Calbindin-D9k). This study provides a theoretical basis for developing functional foods with the AHV peptide as ingredients to improve calcium absorption.

Wheat Bran Polyphenols Ameliorate DSS-Induced Ulcerative Colitis in Mice by Suppressing MAPK/NF-κB Inflammasome Pathways and Regulating Intestinal Microbiota.

Wheat bran (WB) is the primary by-product of wheat processing and contains a high concentration of bioactive substances such as polyphenols. This study analyzed the qualitative and quantitative components of polyphenols in wheat bran and their effects on ulcerative colitis (UC) using the dextran sulfate sodium (DSS)-induced colitis model in mice. The potential mechanism of wheat bran polyphenols (WBP) was also examined. Our findings indicate that the main polyphenol constituents of WBP were phenolic acids, including vanillic acid, ferulic acid, caffeic acid, gallic acid, and protocatechuic acid. Furthermore, WBP exerted remarkable protective effects against experimental colitis. This was achieved by reducing the severity of colitis and improving colon morphology. Additionally, WBP suppressed colonic inflammation via upregulation of the anti-inflammatory cytokine IL-10 and downregulation of pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß) in colon tissues. Mechanistically, WBP ameliorated DSS-induced colitis in mice by inhibiting activation of the MAPK/NF-κB pathway. In addition, microbiome analysis results suggested that WBP modulated the alteration of gut microbiota caused by DSS, with an enhancement in the ratio of Firmicutes/Bacteroidetes and adjustments in the number of Helicobacter, Escherichia-Shigella, Akkermansia, Lactobacillus, Lachnospiraceae_NK4A136_group at the genus level. To conclude, the findings showed that WBP has excellent prospects in reducing colonic inflammation in UC mice.

The digestion and absorption characteristics of human milk phospholipid analogs: a combination study between in vitro and in vivo.

Phospholipids play a crucial role in the growth and neurodevelopment of infants. Currently, soybean phospholipids (SPLs) are the common phospholipid component in most infant formulas (IFs), which, however, shows an obvious difference with the phospholipid (PL) composition of human milk fat. Therefore, in the present study, human milk phospholipid analogs (HMPAs) were prepared by mimicking the composition of PE, PC, PI, PS, and SM in breast milk phospholipids and the composition of the major fatty acids (C16:0, C18:0, C18:1, and C18:2), and their digestion and absorption characteristics were explored using in vitro and mice models. The prepared HMPA contained 26.48% PE, 24.64% PC, 36.19% SM, 6.35% PI, and 6.32% PS, with 40.51% C16:0, 17.02% C18:0, 29.19% C18:1, and 13.26% C18:2, showing different digestive properties relative to SPL. There was little effect on the physical and chemical properties of HMPA under in vitro gastric conditions. The hydrolysis degree, fatty acids release rate, and average particle size decreasing rate of HMPA was significantly higher than that of SPL during digestion in vitro intestine (P < 0.05), showing better digestive process relative to SPL. In terms of the mice model, HMPA had a higher hydrolysis degree in the intestinal tract. Based on the area under curve (AUC) analysis of serum fatty acids, it was found that despite HMPA being absorbed at a slower rate than SPL, it was absorbed more than SPL. In summary, the digestion and absorption of HMPA were preferred to SPL, and these obtained results might provide a theoretical basis for the development and utilization of HMPA in IF.

Differences in fat digestion from milk of different Species: In vitro gastrointestinal digestion model for infants.

The differences in the milk fat digestion from goat milk (GM), camel milk (CM), bovine milk (BM), sheep milk (SM), mare milk (MM) and human milk (HM) using an in vitro gastrointestinal digestion model for simulated infants were investigated. The particle size distributions in goat and mare milk were similar to that of HM after digestion in the small intestine. During in vitro digestion, the zeta-potential change of MM was more consistent with that of HM. After 60 min of gastric digestion, the lipolysis degree (LD) of different milks were<2%, of which the highest LD was MM (1.84%), followed by HM (1.45%). At the end of intestinal digestion, the LD of HM was the highest, reaching 88.47%, and the LD of SM was similar to that of HM, reaching 83.92%, followed by GM (57.00%), BM (40.98%) and MM (39.37%), respectively, the LD of CM was only 29.99%, which was much lower than HM. The results of the glyceride composition hierarchical clustering analysis revealed that MM and HM were clustered into one category at the end of gastric and intestinal digestion. This study provides a scientific basis for the development of lipid ingredients in infant formula.

Effects of Human Milk Fat Substitutes on Lipid Metabolism in First-Weaned Rats.

Although numerous studies indicate that formula-fed infants are more prone to obesity than breastfed ones, the underlying reasons have not been fully elucidated. This study aimed to determine the impact of human milk fat substitutes (HMFS) on the lipid metabolism of first-weaned Sprague Dawley rats. The findings revealed that administering HMFS did not affect the body weight of the rats (control: 298.38 ± 26.73 g, OPO (1,3-dioleic acid-2-palmitoyl triglyceride): 287.82 ± 19.85 g and HMFS: 302.31 ± 19.21 g), but it significantly decreased their body fat content (control: 28.70 ± 1.17 cm3, OPO: 22.51 ± 1.10 cm3 and HMFS: 14.90 ± 0.95 cm3) (p < 0.05). Lipidome analysis revealed that glycerophospholipid was the primary differentiating lipid present in the liver of HMFS-fed rats. The abundance of Bacteroides significantly increased in the intestine of HMFS-fed rats (p < 0.05), and their short-chain fatty acid (SCFA) content significantly increased (p < 0.05). The multi-omics correlation analysis established the "Bacteroidetes-SCFAs-Glycerophospholipid pathway" as a potential mechanism by which administering HMFS affects body fat buildup in first-weaned rats. Additionally, it was found that HMFS administration significantly promoted lipid metabolism in the rat liver at both the gene and protein levels (p < 0.05). These findings serve to underscore the nutritional benefits of HMFS for infants.

Comparative analysis of the volatile components in Chinese breast milk from three regions.

In this study, gas chromatography-mass spectrometry (GC-MS) coupled with Partial least squares Discriminant Analysis (PLS-DA) was used to analyze the volatiles in Chinese breast milk from different cities (Wuhan, Qingdao and Hohhot) and different lactation stages (colostrum and mature milk). The results showed that breast milk contained 122 volatile substances in 9 major groups, with the largest number of olefins (36) and the highest content of acids. The different volatile compounds of breast milk in three cities were heptanal, 2-pentylfuran, (E)-2,4-decadienal, (E)-2-heptenal, (E)-2-nonenal and 1-octen-3-one, colostrum and mature milk were (E)-2-heptenal, (E)-2-decenal, lauric acid, n-decanoic acid, (E)-2-nonenal and octanoic acid. This study might provide scientific data for the development and optimization of formulas that were more suitable for the health of Chinese infants. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01235-4.

The profiles of durian (Durio zibethinus Murr.) shell phenolics and their antioxidant effects on H2O2-treated HepG2 cells as well as the metabolites and organ distribution in rats.

Durian is a nutritious tropical fruit with potent antioxidant, anti-inflammatory, antibacterial and anti-cancer effects. However, the durian shell was mainly discarded as waste, while there were few studies on the characterization of its phenolic profiles, antioxidant activities, and in vivo metabolites. In the present study, a total of 17 compounds were identified in durian shell extract (DSE) by using an ultra-high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS/MS), while 33 metabolites were found in rats' plasma, urine and organ. Moreover, DSE could effectively reduce H2O2-induced oxidative damage in HepG2 cells, reduce the expression of Reactive Oxygen Species (ROS), Malondialdehyde (MDA) and Lactate Dehydrogenase (LDH) and inhibit apoptosis by regulating the expression of Bcl-2-Associated X (BAX), B-Cell Lymphoma 2 (BCL-2), Caspase-3 and Caspase-9 genes and proteins related to mitochondrial pathway apoptosis. This is the first comprehensive report on Durian shell phenolics, their metabolic profiles and underlying mechanisms of the in vitro antioxidant activities.