ABSTRACT
Finding stable and bioavailable calcium supplements is crucial for addressing calcium deficiency. In this study, glycated peptide-calcium chelates (WMPHs-COS-Ca) were prepared from walnut meal protein hydrolysates (WMPHs) and chitosan oligosaccharides (COSs) through the Maillard reaction, and the structural properties and stability of the WMPHs-COS-Ca were characterized. The results showed that WMPHs and COSs exhibited high binding affinities, with a glycation degree of 64.82%. After glycation, Asp, Lys, and Arg decreased by 2.07%, 0.46%, and 1.06%, respectively, which indicated that these three amino acids are involved in the Maillard reaction. In addition, compared with the WMPHs, the emulsifying ability and emulsion stability of the WMPHs-COS increased by 10.16 mg2/g and 52.73 min, respectively, suggesting that WMPHs-COS have better processing characteristics. After chelation with calcium ions, the calcium chelation rate of peptides with molecular weights less than 1 kDa was the highest (64.88%), and the optimized preparation conditions were 5:1 w/w for WMPH-COS/CaCl2s, with a temperature of 50 °C, a chelation time of 50 min, and a pH of 7.0. Scanning electron microscopy showed that the "bridging role" of WMPHs-COS changed to a loose structure. UV-vis spectroscopy and Fourier transform infrared spectrometry results indicated that the amino nitrogen atoms, carboxyl oxygen atoms, and carbon oxygen atoms in WMPHs-COS chelated with calcium ions, forming WMPHs-COS-Ca. Moreover, WMPHs-COS-Ca was relatively stable at high temperatures and under acidic and alkaline environmental and digestion conditions in the gastrointestinal tract, indicating that WMPHs-COS-Ca have a greater degree of bioavailability.
ABSTRACT
Moringa oleifera Lam. is an essential herb used for the treatment of inflammation, diabetes, high blood pressure, and other diseases. In this study, phenolic extracts of M. oleifera leaves were obtained and analyzed. The results showed that the main identifiable phenols were astragalin, chlorogenic acid, isoquercitrin, kaempferitrin, luteolin, quercetin, and rutin. The effects of M. oleifera polyphenol extract (MOPE) on experimental colitis induced by 3% dextran sulfate sodium (DSS) were investigated. The results showed that oral administration of MOPE significantly alleviated the symptoms of DSS-induced colitis. MOPE significantly reduced weight loss, the disease activity index, colon shortening, and mucosal damage. In addition, MOPE attenuated the infiltration of CD3+ T cells, CD177+ neutrophils, and F4/80+ macrophages and significantly inhibited the secretion of IL-6 and TNF-α. After the MOPE administration, the expression of proteins associated with the NF-κB signaling pathway changed. Specifically, compared with that of the DSS group, the protein expression of NF-κB p65 and p-IκBα was downregulated, and the expression of IκBα was upregulated. This study revealed the anti-inflammatory effects and mechanisms of MOPE in the colon, indicating its potential use in preventing inflammation-driven diseases.
ABSTRACT
With the ulcerative colitis (UC) incidence increasing worldwide, it is of great importance to prevent and treat UC. However, efficient treatment options for UC are relatively limited. Due to the potentially serious adverse effects of existing drugs, there is an increasing demand for alternative candidate resources derived from natural and functional foods. Astragalin (AG) is a type of anti-inflammatory flavonoid, with Moringa oleifera and Cassia alata being its main sources. In this study, we investigated the therapeutic effects of AG on mice with dextran sulfate sodium (DSS)-induced colitis. Our results suggested that AG treatment reduced weight loss and the disease activity index (DAI), prevented colon shortening and alleviated colonic tissue damage. AG treatment reduced the expression of pro-inflammatory cytokines and related mRNAs (such as TNF-α, IL-6, and IL-1ß), inhibited colonic infiltration by macrophages and neutrophils, ameliorated metabolic endotoxemia, and improved intestinal mucosal barrier function (increased expression levels of mRNAs such as ZO-1, occludin, and Muc2). Western blot analysis revealed that AG downregulated the NF-κB signaling pathway. Moreover, AG treatment partially reversed the alterations in the gut microbiota in colitis mice, mainly by increasing the abundance of potentially beneficial bacteria (such as Ruminococcaceae) and decreasing the abundance of potentially harmful bacteria (such as Escherichia-Shigella). Ruminococcaceae and Enterobacteriaceae (Escherichia-Shigella) were thought to be the key groups affected by AG to improve UC. Therefore, AG might exert a good anti-UC effect through microbiota/LPS/TLR4/NF-kB-related pathways in mice. The results of this study reveal the anti-inflammatory effect and mechanism of AG and provide an important reference for studying the mechanisms of natural flavonoids involved in preventing inflammation-driven diseases.