Metabolomics Research Reveals the Mechanism of Action of Astragalus Polysaccharide in Rats with Digestive System Disorders

Chemical Composition and Therapeutic Effects of Several Astragalus Species (Fabaceae)

The review integrates information on the component composition and biological activity of some Astragalus L. (Fabaceae) species from studies reported over the past 5-7 years. The aerial and underground parts of 34 Astragalus species contain triterpene saponins, flavonoids, polisaccharides, tannins, free organic acids, higher fatty acids, vitamins, trace elements, and other constituents. Among the Astragalus species, A. membranaceus (Fisch.) Bunge is the best studied in terms of component composition and biological activity. Anti-inflammatory, immunomodulatory, antioxidant, anticancer, cardioprotective, and hepathoprotective activities have been experimentally detected in total bioactive substances, fractions, and individual compounds extracted from various parsts of A. membranaceus and A. membranaceus var. mongholicus in vitro and in vivo. The composition and biological effects of other Astragalus species are still poorly understood. The review summarizes the recent advances in studying new compounds extracted from Astragalus species and their biological activities.

Impact of purple sweet potato (Ipomoea batatas L.) polysaccharides on the fecal metabolome in a murine colitis model

Purple sweet potato polysaccharides (PSPP) play an important role in regulating the gut microbiota, modulating intestinal immunity and ameliorating colonic inflammation. In this study, the impact of two PSPPs (PSWP-I and PSAP-I) on the metabolomic profiling of feces from dextran sulfate sodium (DSS)-induced colitis mice was evaluated by ultra-high performance liquid chromatography coupled with triple time-of-flight tandem mass spectrometry (UPLC-Triple-TOF-MS/MS). Results indicated that there were twenty-five metabolites with significant changes and four remarkable metabolic pathways, i.e., cutin, suberine and wax biosynthesis, biosynthesis of unsaturated fatty acids, fatty acid biosynthesis, and steroid hormone biosynthesis. Two key biomarkers of oleic acid and 17-hydroxyprogesterone were screened that responded to PSPPs in colitis mice. The identified metabolites were correlated with the amelioration of intestinal immune function and the modulation of the gut microbiota. Nine pro-inflammatory and eight anti-inflammatory compounds responded to PSPPs, which were related to Bacteroides, norank_f__Clostridiales_vadinBB60_group, unclassified_o__Bacteroidales, Rikenella and Lachnospiraceae_UCG-001. Moreover, PSWP-I and PSAP-I had different regulating effects on intestinal metabolites. Our results revealed a possible metabolomic mechanism of PSPPs to regulate intestinal inflammation function.

Purple sweet potato polysaccharides (PSPP) play an important role in regulating the gut microbiota, modulating intestinal immunity and ameliorating colonic inflammation.

Astragalus polysaccharide prevents ferroptosis in a murine model of experimental colitis and human Caco-2 cells via inhibiting NRF2/HO-1 pathway

Ulcerative colitis (UC) is a relapsing and remitting inflammatory bowel disease (IBD), but current conventional drugs lack efficacy. Astragalus polysaccharide (APS) is an active ingredient of Astragalus membranaceus and has been shown to ameliorate experimental colitis. In the present study, we aimed to investigate how APS affects the ferroptosis of intestinal epithelial cells in dextran sulfate sodium (DSS)-induced experimental colitis in mice. Our data showed that APS administration attenuated total weight loss, colon length shortening, disease activity index (DAI) scores, histological damage, and the expression of inflammatory cytokines in the colon of DSS-challenged mice. Moreover, we observed that treatment with APS obviously inhibited ferroptosis in both DSS-challenged mice and RSL3-stimulated Caco-2 cells, as indicated by the decrease in the expression of ferroptosis-associated genes (PTGS2, FTH, and FTL) and the levels of surrogate ferroptosis markers (MDA, GSH, and iron load). Mechanistically, the inhibitory effects of APS on ferroptosis in DSS-challenged mice and RSL3-stimulated Caco-2 cells were associated with the NRF2/HO-1 pathway. Collectively, our findings identify a new role of APS in preventing ferroptosis in a murine model of experimental colitis and human Caco-2 cells via inhibiting NRF2/HO-1 pathway.

Immunomodulatory Effect of a New Ingredients Group Extracted from Astragalus Through Membrane Separation Technique

Introduction

Astragalus is a commonly used traditional Chinese medicine in China, which has been widely applied to enhance the immunomodulatory function of the body. The main bioactive components are complicated. To explore the role of the components, various techniques have been applied in Astragalus extraction. Membrane separation technique featured with green processing condition and high efficiency is of signification interest in the application of Astragalus treatment.

Methods

In this study, a new ingredients group A4 was separated from Astragalus using membrane separation technique. The quantification and identification of A4 were achieved by UV-vis spectrometry and UPLC-MS measurements. Pathological approaches along with serum metabolomics were utilized to study the immunoprotective effects of the extracts and explore the underlying mechanisms on metabolic activity.

Results

It was observed that A4 could promote the secretion of IL-2 and IFN-γ, stimulate the activated CD4⁺CD25⁺ and CD8⁺ CD25⁺ T lymphocytes in splenocytes and protect rat spleen to some extent. Seven crucial biomarkers that related to immunity regulations were screened out and identified through serum metabonomic analysis coupled with nuclear magnetic resonance. The enrichment analysis revealed that A4 alleviated the immune dysfunction by modulating amino acid metabolism and energy metabolism for the first time.

Conclusion

The new ingredients group A4 isolated from the Astragalus membrane can reduce the immune dysfunction by regulating the amino acid metabolism and energy metabolism of rats.

Chinese herbal decoction (Danggui Buxue Tang) supplementation augments physical performance and facilitates physiological adaptations in swimming rats

Context: Danggui Buxue Tang (DBT), one of the popular Danggui (DG) decoctions, has traditionally been used to nourish 'qi' (vital energy) and enrich 'blood' (body circulation). DBT may possess performance-enhancing effects.Objective: This work determines whether DBT can improve physical capacity and alter energy expenditure under exercise training.Materials and methods: Forty male Wistar rats were assigned to four groups: sedentary (SE), exercise training (ET), ET supplemented with 0.3 g/kg rat/d DG extract, and ET supplemented with 1.8 g/kg rat/d DBT extract. The supplementations were administered via oral gavage. During the 21-day treatment period, the exercised groups were subjected to a protocol of swimming training with a gradually increased load. Physical performance evaluation was assessed using the forelimb grip strength test and an exhaustive swimming test. Muscle glycogen contents and exercise-related biochemical parameters were analysed.Results: Both herbal supplementations remarkably increased the grip strength (DG by 49.7% and DBT by 85.7%) and prolonged the swimming time (DG by 48.4% and DBT by 72.7%) compared with SE. DBT spared a certain amount of glycogen in the muscle cells under exercise training. Regarding the regulation of fuel usage, DBT had a positive impact alongside ET on promoting aerobic glycolysis via significantly decreasing serum lactate by 31.6% and lactic dehydrogenase levels by 61.8%.Conclusions: This study found that DBT could be considered a promising sports ergogenic aid for athletic population or fitness enthusiasts. Future work focussing on isolating the bioactive components that truly provide the ergogenic effects would be of interest.

Exploring Metabolic Signature of Protein Energy Wasting in Hemodialysis Patients

End-stage renal disease patients undergoing maintenance hemodialysis (HD) are vulnerable to the protein energy wasting (PEW) syndrome. Identification and diagnosis of PEW relies on clinical processes of judgment dependent on fulfilling multiple criteria drawn from serum biochemistry, weight status, predictive muscle mass, dietary energy and protein intakes. Therefore, we sought to explore the biomarkers’ signature with plasma metabolites of PEW by using ¹H-nuclear magnetic resonance for an untargeted metabolomics approach in the HD population, to understand metabolic alteration of PEW. In this case-controlled study, a total of 53 patients undergoing chronic HD were identified having PEW based on established diagnostic criteria and were age- and sex-matched with non-PEW (n = 53) HD patients. Fasting predialysis plasma samples were analyzed. Partial least square discriminant analysis demonstrated a significant separation between groups for specific metabolic pattern alterations. Further quantitative analysis showed that the level of 3-hydroxybutyrate, acetate, arabinose, maltose, ribose, sucrose and tartrate were significantly increased whilst creatinine was significantly decreased (all p < 0.05) in PEW subjects. Pathway analysis indicated that PEW-related metabolites reflected perturbations in fatty acid mechanism and induction of glyoxylate and dicarboxylate pathway attributed to gluconeogenesis. These results provide preliminary data in understanding metabolic alteration of PEW and corresponding abnormal metabolites that could potentially serve as biomarkers of PEW.

1H-NMR Metabolomics Analysis of the Effect of Rubusoside on Serum Metabolites of Golden Hamsters on a High-Fat Diet

Rubusoside is a natural sweetener and the active component of Rubus suavissimus. The preventive and therapeutic effect of rubusoside on high-fat diet-induced (HFD) serum metabolite changes in golden hamsters was analyzed by ¹H-NMR metabolomics to explore the underlying mechanism of lipid metabolism regulation. ¹H-NMR serum metabolomics analyses revealed a disturbed amino acid-, sugar-, fat-, and energy metabolism in HFD animals. Animals supplemented with rubusoside can partly reverse the metabolism disorders induced by high-fat diet and exerted good anti-hypertriglyceridemia effect by intervening in some major metabolic pathways, involving amino acid metabolism, synthesis of ketone bodies, as well as choline and 4-hydroxyphenylacetate metabolism. This study indicates that rubusoside can interfere with and normalize high-fat diet-induced metabolic changes in serum and could provide a theoretical basis to establish rubusoside as a potentially therapeutic tool able to revert or prevent lipid metabolism disorders.