Structural characterization of Poria cocos oligosaccharides and their effects on the hepatic metabolome in high-fat diet-fed mice

Metabolomic profile of plasma approach to investigate the mechanism of Poria cocos oligosaccharides attenuated LPS-induced acute lung injury in mice

Poria cocos (Schw.) Wolf (PCW) are the dried sclerotia of Poaceae fungus Poria cocos that contain many biological activity ingredients such as polysaccharides and triterpenoids. The carbohydrates from Poria cocos have been proven to possess anti-inflammatory and antioxidant effects. This study aimed to investigate the impact and mechanism of Poria cocos oligosaccharides (PCO) protecting mice against acute lung injury (ALI). We examined the histopathological analysis of lung injury, inflammatory, and edema levels to evaluate the benefits of PCO during ALI. As a result, PCO improved the lipopolysaccharide (LPS) induced lung injury and decreased the inflammatory cytokines of lung tissue. Simultaneously, PCO alleviated lung edema by regulating the expression of aquaporin5 (AQP5) and epithelial Na+ channel protein (ENaC-α). Additionally, untargeted metabolomics was performed on the plasma of ALI mice via HUPLC-Triple-TOF/MS. The results indicated that linoleic acid, linolenic acid, arachidonic acid, carnosine, glutamic acid, and 1-methylhistamine were the biomarkers in ALI mice. Besides, metabolic pathway analysis suggested PCO affected the histidine and fatty acid metabolism, which were closely associated with inflammation and oxidative reaction of the host. Consequently, the effects of PCO inhibiting inflammation and edema might relate to the reducing pro-inflammatory mediators and the reverse of abnormal metabolic pathways.

Tree peony seed oil alleviates hyperlipidemia and hyperglycemia by modulating gut microbiota and metabolites in high-fat diet mice

With the changes of people's lifestyle, hyperlipidemia and hyperglycemia which were induced from a diet high in both fat and sugar have become serious health concerns. Tree peony seed oil (PSO) is a novel kind of edible oil that shows great potential in the food industry because of its high constituent of unsaturated fatty acids. Based 16S rRNA and gut untargeted metabolomics, this study elucidated that the mechanism of PSO regulating blood glucose (Glu) and lipids. The impact of PSO on gut microbiota balance and gut metabolites of mice with a high-fat diet (HFD) was evaluated. The findings indicated that PSO decreased HFD mice's body weight and fat accumulation, ameliorating the levels of blood lipid, reduced liver fat vacuole levels. What's more PSO modulated the proportion of gut microbiota in HFD mice and enhanced the abundance of probiotics. Furthermore, untargeted metabolomic analysis revealed that PSO not only impacted the generation of short-chain fatty acids (SCFAs) by gut microorganism and altered metabolic pathway but exerted influence on secondary bile acids (BA), amino acid metabolism, and various other metabolites. These results suggested that PSO has the potential function for mitigating HFD-induced hyperlipidemia and hyperglycemia by regulating gut microbiota and host metabolism.

Structural characterization of Astragalus polysaccharide-D1 and its improvement of low-dose metformin effect by enriching Staphylococcus lentus

To explore the adjuvant therapy drugs of low-dose metformin, one homogeneous polysaccharide named APS-D1 was purified from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Its chemical structure was characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-D1 (7.36 kDa) consisted of glucose, galactose, and arabinose (97.51 %:1.56 %:0.93 %). It consisted of →4)-α-D-Glcp-(1→ residue backbone with →3)-β-D-Galp-(1→ residue and terminal-α/β-D-Glcp-(1→ side chains. APS-D1 could significantly improve inflammation (TNF-α, LPS, and IL-10) in vivo. Moreover, APS-D1 improved the curative effect of low-dose metformin without adverse events. APS-D1 combined with low-dose metformin regulated several gut bacteria, in which APS-D1 enriched Staphylococcus lentus to produce l-carnitine (one of 136 metabolites of S. lentus). S. lentus and l-carnitine could improve diabetes, and reduction of S. lentusl-carnitine production impaired diabetes improvement. The combination, S. lentus, and l-carnitine could promote fatty acid oxidation (CPT1) and inhibit gluconeogenesis (PCK and G6Pase). The results indicated that APS-D1 enhanced the curative effect of low-dose metformin to improve diabetes by enriching S. lentus, in which the effect of S. lentus was mediated by l-carnitine. Collectively, these findings support that low-dose metformin supplemented with APS-D1 may be a favorable therapeutic strategy for type 2 diabetes.

Chemical structures, extraction and analysis technologies, and bioactivities of edible fungal polysaccharides from Poria cocos: An updated review

Poria cocos is a popular medicinal food. Polysaccharides are the key component of Poria cocos, forming 70-90 % of the dry sclerotia mass. Recent studies indicate that Poria cocos polysaccharides (PCP-Cs) have multiple beneficial functions and applications. A literature search was conducted using the Web of Science Core Collection and PubMed databases. For this review, we provided an updated research progress in chemical structures, various extraction and analysis technologies, bioactivities of PCP-Cs, and insights into the directions for future research. The main polysaccharides identified in Poria cocos are water-soluble polysaccharides and acidic polysaccharides. Hot water, alkali, supercritical fluid, ultrasonic, enzyme, and deep eutectic solvent-based methods are the most common methods for PCP-Cs extraction. Technologies such as near-infrared spectroscopy, high-performance liquid chromatography, and ultraviolet-visible spectrophotometry, are commonly used to evaluate the qualities of PCP-Cs. In addition, PCP-Cs have antioxidant, immunomodulatory, neuroregulatory, anticancer, hepatoprotective, and gut microbiota regulatory properties. Future research is needed to focus on scaling up extraction, enhancing quality control, elucidating mechanisms of bioactivities, and the utilisation of PCP-Cs in food industries. Overall, Poria cocos is a good source of edible fungi polysaccharides, which can be developed into functional foods with potential health benefits.

Machine learning-based monosaccharide profiling for tissue-specific classification of Wolfiporia extensa samples

Machine learning (ML) has been used for many clinical decision-making processes and diagnostic procedures in bioinformatics applications. We examined eight algorithms, including linear discriminant analysis (LDA), logistic regression (LR), k-nearest neighbor (KNN), random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), Naïve Bayes classifier (NB), and artificial neural network (ANN) models, to evaluate their classification and prediction capabilities for four tissue types in Wolfiporia extensa using their monosaccharide composition profiles. All 8 ML-based models were assessed as exemplary models with AUC exceeding 0.8. Five models, namely LDA, KNN, RF, GBM, and ANN, performed excellently in the four-tissue-type classification (AUC > 0.9). Additionally, all eight models were evaluated as good predictive models with AUC value > 0.8 in the three-tissue-type classification. Notably, all 8 ML-based methods outperformed the single linear discriminant analysis (LDA) plotting method. For large sample sizes, the ML-based methods perform better than traditional regression techniques and could potentially increase the accuracy in identifying tissue samples of W. extensa.

Polysaccharides: The Potential Prebiotics for Metabolic Associated Fatty Liver Disease (MAFLD)

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is recognized as the most prevalent chronic liver disease globally. However, its pathogenesis remains incompletely understood. Recent advancements in the gut-liver axis offer novel insights into the development of MAFLD. Polysaccharides, primarily derived from fungal and algal sources, abundantly exist in the human diet and exert beneficial effects on glycometabolism, lipid metabolism, inflammation, immune modulation, oxidative stress, and the release of MAFLD. Numerous studies have demonstrated that these bioactivities of polysaccharides are associated with their prebiotic properties, including the ability to modulate the gut microbiome profile, maintain gut barrier integrity, regulate metabolites produced by gut microbiota such as lipopolysaccharide (LPS), short-chain fatty acids (SCFAs), and bile acids (BAs), and contribute to intestinal homeostasis. This narrative review aims to present a comprehensive summary of the current understanding of the protective effects of polysaccharides on MAFLD through their interactions with the gut microbiota and its metabolites. Specifically, we highlight the potential molecular mechanisms underlying the prebiotic effects of polysaccharides, which may give new avenues for the prevention and treatment of MAFLD.

Structural characterization and anti-inflammatory activity of polysaccharides from Astragalus membranaceus

In this study, two homogeneous polysaccharides (APS-A1 and APS-B1) were isolated from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Their chemical structures were characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-A1 (2.62 × 10⁶ Da) was a 1,4-α-D-Glcp backbone with a 1,4,6-α-D-Glcp branch every ten residues. APS-B1 (4.95 × 10⁶ Da) was a heteropolysaccharide composed of glucose, galactose, and arabinose (75.24:17.27:19.35). Its backbone consisted of 1,4-α-D-Glcp, 1,4,6-α-D-Glcp, 1,5-α-L-Araf and the sidechains composed of 1,6-α-D-Galp and T-α/β-Glcp. Bioactivity assays showed that APS-A1 and APS-B1 had potential anti-inflammatory activity. They could inhibit the production of inflammatory factors (TNF-α, IL-6, and MCP-1) in LPS-stimulated RAW264.7 macrophages via NF-κB and MAPK (ERK, JNK) pathways. These results suggested that the two polysaccharides could be potential anti-inflammatory supplements.

Poria cocos oligosaccharides ameliorate dextran sodium sulfate-induced colitis mice by regulating gut microbiota dysbiosis

Poria cocos, a widely accepted function food in China, has multiple pharmacological activities. This study aimed to investigate the therapeutic effect and molecular mechanism of Poria cocos oligosaccharides (PCOs) against dextran sodium sulfate (DSS)-induced mouse colitis. In this study, BALB/c mice were treated with 3% (w/v) DSS for seven days to establish a colitis model. The results showed that oral administration of PCOs (200 mg per kg per day) significantly reversed the changes in the physiological indices in colitis mice, including body weight, disease activity index scores (DAI), spleen index, and colon length. From the qRT-PCR assay, it was observed that PCOs suppressed the mRNA expression of pro-inflammatory cytokines, such as Tnf-α, Il-1β, and Il-6. In addition, PCOs protected the intestinal barrier from damage by promoting the expression of mucins and tight junction proteins at both mRNA and protein levels. Upon 16S rDNA sequencing, it was observed that PCO treatment partly reversed the changes in the gut microbiota of colitis mice by selectively regulating the abundance of specific bacteria. And Odoribacter, Muribaculum, Desulfovibrio, Oscillibacter, Escherichia-Shigella, and Turicibacter might be the critical bacteria in improving colitis via PCOs. Finally, using antibiotic mixtures to destroy the intestinal bacteria, we documented that PCO fermentation broth (PCO FB) instead of PCOs prevented the occurrence of colitis in gut microbiota-depleted mice. In conclusion, PCOs showed a protective effect on colitis by reversing gut microbiota dysbiosis. Our study sheds light on the potential application of PCOs as a prebiotic for treating colitis.