The potential of dietary fiber in building immunity against gastrointestinal and respiratory disorders.

The numerous health benefits of dietary fibers (DFs) justify their inclusion in human diets and biomedical products. Given the short- and long-term human impacts of the COVID-19 virus on human health, the potential of DFs in building immunity against gastrointestinal and respiratory disorders is currently receiving high attention. This paper reviews the physicochemical properties of DFs, together with their immune functions and effects on the gastrointestinal tract and respiratory system mainly based on research in the last ten years. Possible modes of action of DFs in promoting health, especially building immunity, are explored. We seek to highlight the importance of understanding the exact physical and chemical characteristics and molecular behaviors of DFs in providing specific immune function. This review provides a perspective beyond the existing recognition of DFs' positive effects on human health, and offers a theoretical framework for the development of special DFs components and their application in functional foods and other therapeutic products against gastrointestinal and respiratory disorders. DFs enhance immunity from gastrointestinal and respiratory diseases to promote host health.

Purification, structural characterization, and immunomodulatory activity of two polysaccharides from Portulaca oleracea L.

In present study, two water-soluble polysaccharides designated as POL-1 and POL-2 were purified from purslane and their structural characteristics as well as immunomodulatory activity were investigated. The weight-average molecular weight (Mw) of POL-1 and POL-2 were determined to be 64,100 Da and 21,000 Da, respectively. Comprehensive techniques including UV, IR, GC-MS, and NMR were applied to deduced that POL-1 was a pectin polysaccharide homogalacturonan (HG) consisting of →4)-α-GalpA-(1→ with methyl ester degree of 9.71 % and acetylation degree of 0.34 %, while POL-2 was composed of a 1, 4-linked ß-Galp backbone substituted by short side chain →4)-α-Glcp-(1→ and →6)-α-Glcp-(1→. The →4)-α-Glcp-(1→ was attached at the O-6 position of →4)-ß-Galp-(1→. TEM further revealed that POL-1 was non-branched single chains, while POL-2 was entangled microstructure with side chains. Moreover, POL-2 significantly promoted macrophage phagocytosis as well as the secretion of NO and cytokines (TNF-α, IL-6) through activating NF-κB signaling pathway, thus demonstrating potential immunomodulatory activity. These findings suggested that purslane may be exploited as a potential adjuvant and dietary supplement with immunostimulatory purpose.

Inhibitory effect of quercetin-3-O-α-rhamnoside, p-coumaric acid, phloridzin and 4-O-ß-glucopyranosyl-cis-coumaric acid on rats liver microsomes cytochrome P450 enzyme activities.

P-coumaric acid, phloridzin, quercetin-3-O-α-rhamnoside and 4-O-ß-glucopyranosyl-cis-coumaric acid isolated in Malus micromalus Makino fruit were investigated the inhibitory activity of cytochrome CYP450 enzyme by the probe test method of rat liver microsomes in vitro, and determined the role in drug metabolism and/or toxicology. Enzymatic kinetics method was used to determine the inhibition type of these components and corresponding inhibition constants. The results demonstrated that all the 4 compounds had no significance to inhibit the activities of CYP2E1 and CYP2C11. P-coumaric acid, phloridzin and quercetin-3-O-α-rhamnoside had a weak inhibitory effect on CYP3A4, which belonged to the competitive inhibitory type with inhibitory constants of 10.56, 30.79 and 40.29 µmol L-1, respectively. 4-O-ß-glucopyranosyl-cis-coumaric acid had a moderate inhibitory effect on CYP3A4, which belonged to the anti-competitive inhibition type and the inhibition constant was 5.56 µmol L-1. The CYP1A2 could be weakly inhibited by p-coumaric acid in the competitive type, and the inhibition constant is 25.20 µmol L-1 4-O-ß-glucopyranosyl-cis-coumaric acid exhibited anti-competitive inhibition of CYP1A2 with an inhibition constant of 19.91 µmol L-1, and the inhibition effect was weak. The results will be useful to optimize the clinical dosage regimen and avoid drug-drug interactions when it is utilized comminating with other medicines in the clinic.

Patrinoside and Patrinoside A from Patrinia scabiosaefolia Improve Insulin Resistance by Inhibiting NF-κB, MAPK Pathways and Oxidative Stress in RAW264.7 and 3 T3-L1 Cells.

Patrinia scabiosaefolia, as traditional food and medicine plant, was used to treat appendicitis, enteritis, and hepatitis for thousand years in China. Patrinoside and patrinoside A isolated from P. scabiosaefolia could significantly improve insulin resistance (IR) by activating PI-3 K/AKT signaling pathway in our previous study. Since IR is closely related to inflammation, their anti-inflammatory activities in RAW264.7 inflammatory model induced by LPS and in 3 T3-L1 IR inflammatory model induced by TNF-α were evaluated to identify whether the effects on improving IR related to anti-inflammatory activity. In RAW264.7 cells, patrinoside and patrinoside A significantly inhibited the transcription and secretion of inflammatory mediators NO, TNF-α, and IL-6. Western blot analysis showed that the significant inhibition of phosphorylation of IκB and P65 and P38, ERK and JNK suggested that the effects were exerted through NF-κB pathway and MAPK pathway. In 3 T3-L1 cells, patrinoside and patrinoside A also inhibited the activation of NF-κB and MAPK pathways through inhibiting the transcriptions of inflammatory cytokines IL-6 and chemokines MCP-1 and MIP-1α. These events resulted in the inhibition of macrophages migration to adipocytes. In addition, patrinoside and patrinoside A ameliorated oxidative stress by inhibiting ROS release in LPS-stimulated RAW264.7 cells. In conclusion, patrinoside and patrinoside A could active PI-3 K/AKT pathway, inhibit NF-κB pathway, MAPK pathway, and improve oxidative stress, which showed multipathways on improving IR. These results provided the scientific basis for material basis and mechanism on improving IR of P. scabiosaefolia.

Rapid identification of α-glucosidase inhibitors from Poria using spectrum-effect, component knock-out, and molecular docking technique.

Instruction: Poria (Poria cocos) is known for its health-promoting effects and is consumed as a food due to its potential hypoglycemic activity. However, the composition of Poria is complex, and the bioactive compounds that inhibit α-glucosidase are not clear. Methods: In this study, the fingerprint of the Poria methanol extract characterized by high-performance liquid chromatography (HPLC) and the model of the corresponding spectrum-effect relationship for α-glucosidase was first established to screen the active compounds from Poria. Then, the predicted bioactive compounds were knocked out and identified using mass spectrometry. Finally, the potential binding sites and main bonds of each compound with α-glucosidase were studied using molecular docking. Results: The results have shown that at least 11 compounds from Poria could inhibit α-glucosidase effectively. Moreover, eight individual compounds, i.e., poricoic acid B (P8), dehydrotumulosic acid (P9), poricoic acid A (P10), polyporenic acid C (P12), 3- epidehydrotumulosic acid (P13), dehydropachymic acid (P14), 3-O-acetyl-16α-hydroxytrametenolic acid (P21), and pachymic acid (P22), were identified, and they exhibited effective inhibitory activity against α-glucosidase. Discussion: The possible inhibitory mechanism of them based on molecular docking showed that the binding sites are mainly found in the rings A, B, and C of these compounds, and C-3 C-16 and side chains of C-17, with the phenylalanine, arginine, tyrosine, histidine, and valine of α-glucosidase. The main interactions among them might be alkyl and hydrogen bonds, which theoretically verified the inhibitory activity of these compounds on α-glucosidase. The achievements of this study provided useful references for discovering bioactive compounds with hypoglycemic effects from Poria.