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/ß-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.

5-Aminosalicylic acid ameliorates dextran sulfate sodium-induced colitis in mice by modulating gut microbiota and bile acid metabolism.

Colitis develops via the convergence of environmental, microbial, immunological, and genetic factors. The medicine 5-aminosalicylic acid (5-ASA) is widely used in clinical practice for colitis (especially ulcerative colitis) treatment. However, the significance of gut microbiota in the protective effect of 5-ASA on colitis has not been explored. Using a dextran sulfate sodium (DSS)-induced colitis mouse model, we found that 5-ASA ameliorated colitis symptoms in DSS-treated mice, accompanied by increased body weight gain and colon length, and a decrease in disease activity index (DAI) score and spleen index. Also, 5-ASA alleviated DSS-induced damage to colonic tissues, as indicated by suppressed inflammation and decreased tight junction, mucin, and water-sodium transport protein levels. Moreover, the 16S rDNA gene sequencing results illustrated that 5-ASA reshaped the disordered gut microbiota community structure in DSS-treated mice by promoting the abundance of Bifidobacterium, Lachnoclostridium, and Anaerotruncus, and reducing the content of Alloprevotella and Desulfovibrio. Furthermore, 5-ASA improved the abnormal metabolism of bile acids (BAs) by regulating the Farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5) signaling pathways in DSS-treated mice. In contrast, 5-ASA did not prevent the occurrence of colitis in mice with gut microbiota depletion, confirming the essential role of gut microbiota in colitis treatment by 5-ASA. In conclusion, 5-ASA can ameliorate DSS-induced colitis in mice by modulating gut microbiota and bile acid metabolism. These findings documented the new therapeutic mechanisms of 5-ASA in clinical colitis treatment.

Vine Tea (Ampelopsis grossedentata) Extract Attenuates CCl4 -Induced Liver Injury by Restoring Gut Microbiota Dysbiosis in Mice.

SCOPE: Vine tea (Ampelopsis grossedentata), a traditional Chinese tea, has displayed various biological activities. The authors aim to investigate the effect of Vine Tea (Ampelopsis grossedentata) extract (VTE) on carbon tetrachlorid (CCl4 )induced acute liver injury (ALI) in mice and to explore the underlying role of gut microbiota during the treatment. METHODS AND RESULTS: C57BL/6J mice injected with CCl4 are treated with VTE for 6 weeks. By using H&E staining, immunofluorescence staining, quantitative real-time (qRT)-PCR, and western blot, it is shown that VTE treatment significantly ameliorates hepatocyte necrosis, alleviates the mRNA levels of toll-like receptor 4 (Tlr4), interleukin (Il)-6, inducible nitric oxide synthase (iNOS), acetyl-CoA carboxylase 1 (Acc1), and increases the mRNA levels of peroxisome proliferator-activated receptor gamma (Ppar-γ) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (Hmg-coar) compared to the CCl4 group. Also, VTE abrogates the decreased mRNA expressions of zonula occludens-1 (Zo-1), Occludin, and Mucin1 in colon tissues. Using microbial 16S rDNA sequencing, VTE treatment significantly downregulates the abundances of some harmful intestinal bacteria like Helicobacter and Oscillibacter. In contrast, VTE upregulates the contents of several beneficial bacteria, such as Ruminococcaceae_UCG-014 and Eubacterium_fissicatena_group. Further, VTE fails to improve ALI in the mice with gut microbiota depletion using antibiotic treatment. CONCLUSIONS: The studies suggest that VTE exhibits a protective effect against CCl4 -induced ALI in mice by alleviating hepatic inflammation, suppressing intestinal epithelial barrier injury, and restoring gut microbiota dysbiosis.

Plasma metabolomic profiles reveal regulatory effect of chitosan oligosaccharides on loperamide-induced constipation in mice.

Chitosan oligosaccharides (COS) can improve the symptoms of constipation. In this study, we further explored the regulator effect of COS on aberrant plasma metabolomics in constipated mice. Using untargeted metabolomic analysis by ultra-performance liquid chromatography-mass spectrometer (UPLC-MS), we identified several most significantly changed metabolic pathways in plasma of constipated mice induced by loperamide, including those correlated with the metabolisms of sphingolipid, glycerophospholipid, tryptophan, bile acids, unsaturated fatty acids, and amino acids. The changes in these metabolic pathways were reversed by COS treatment largely. Furthermore, the mRNA levels of some key target genes related to the above metabolic pathways in colon samples were detected by reverse transcription-polymerase chain reaction analysis. We showed that COS significantly suppressed the abnormal expression of these genes, including ceramide glucosyltransferase (CGT), sphingolipid 4-desaturase (DEGS2), alkaline ceramidase (ACER1), sphingosine kinase 2 (SPHK2), lysophosphatidylcholine acyltransferase (LPCAT1), and aromatic-L-amino-acid (DDC). These data provide insight into the mechanisms by which COS ameliorates loperamide-induced constipation in mice.

Modulation of gut microbiota and intestinal metabolites by lactulose improves loperamide-induced constipation in mice.

Lactulose is a common laxative and has been widely applied to clinical treatment for constipation. This study aimed to explore the improving effect of lactulose on constipation through the mediation of gut microbiota and intestinal metabolites. BALB/c mice with constipation induced by loperamide were orally treated with lactulose for four weeks. After the treatment, the constipation-related factors were determined. The effect of lactulose on the composition of gut microbiota was assessed by 16S rDNA gene sequencing. Gas chromatography or liquid chromatography-mass spectrometer (GC/LC-MS) analysis was used for the quantification of intestinal metabolites. The treatment of constipated mice with lactulose accelerated intestinal motility, suppressed inflammatory responses, protected gut barrier, and improved metabolisms of water and salt in the intestinal tract. These therapeutic effects were attributed to the reversed gut microbiota dysfunction, which conferred the benefit to the production of intestinal metabolites including bile acids, short-chain fatty acids, and tryptophan catabolites. Further, the depletion of intestinal flora from loperamide- or (loperamide + lactulose)-treated mice confirmed the significance of gut microbiota in the mediation of constipation. In summary, this study leads us to propose that lactulose may improve constipation through a prebiotic effect on gut microbiota and intestinal metabolites.

Chitosan oligosaccharides attenuate loperamide-induced constipation through regulation of gut microbiota in mice.

This study was designed to explore the improvement of chitosan oligosaccharides (COS) on constipation through regulation of gut microbiota. Here, we proved that COS treatment profoundly boosted intestinal motility, restrained inflammatory responses, improved water-electrolyte metabolism and prevented gut barrier damage in constipated mice induced by loperamide. By 16S rDNA gene sequencing, the disbalanced gut microbiota was observed in constipated mice, while COS treatment statistically reversed the abundance changes of several intestinal bacteria at either phylum, family and genus levels, which partly led to the balance in production of intestinal metabolites including bile acids, short-chain fatty acids and tryptophan catabolites. In addition, COS failed to relieve the constipation in mice with intestinal flora depletion, confirming the essentiality of gut microbiota in COS-initiated prevention against constipation. In summary, COS can ameliorate the development of loperamide-induced constipation in mice by remodeling the structure of gut microbial community.

Intestinal microbiome and NAFLD: molecular insights and therapeutic perspectives.

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of dysregulated lipid and glucose metabolism, which is often associated with obesity, dyslipidemia and insulin resistance. In view of the high morbidity and health risks of NAFLD, the lack of effective cure has drawn great attention. In recent years, a line of evidence has suggested a close linkage between the intestine and liver diseases such as NAFLD. We summarized the composition and characteristics of intestinal microbes and reviewed molecular insights into the intestinal microbiome in development and progression of NAFLD. Intestinal microbes mainly include bacteria, archaea, viruses and fungi, and the crosstalk between non-bacterial intestinal microbes and human liver diseases should be paid more attention. Intestinal microbiota imbalance may not only increase the intestinal permeability to gut microbes but also lead to liver exposure to harmful substances that promote hepatic lipogenesis and fibrosis. Furthermore, we focused on reviewing the latest "gut-liver axis"-targeting treatment, including the application of antibiotics, probiotics, prebiotics, synbiotics, farnesoid X receptor agonists, bile acid sequestrants, gut-derived hormones, adsorbents and fecal microbiota transplantation for NAFLD. In this review, we also discussed the potential mechanisms of "gut-liver axis" manipulation and efficacy of these therapeutic strategies for NAFLD treatment.

Improvement on metabolic syndrome in high fat diet-induced obese mice through modulation of gut microbiota by sangguayin decoction.

ETHNOPHARMACOLOGICAL RELEVANCE: Our previous research found that Sangguayin (SGY) deccoction made by four dietary and medicinal plant components (Leaf of Morus alba L., Root of Pueraria lobata (Willd.) Ohwi., Root of Dioscorea opposita Thunb. and Fruit of Momordica charantia L.) showed significant anti-diabetic effects on db/db mice and high fat diet induced obese mice. Nevertheless, it remained unclear what the role of gut microbiota in the hypoglycaemia effects of SGY. AIMS OF THE STUDY: This study aimed to examine the beneficial effects of Sangguayin Deccoction against metabolic syndrome and and its regulating role in gut microbiota and hepatic metabolome. MATERIALS AND METHODS: C57BL/6J mice were divided to a normal chow diet (NCD), high-fat diet (HFD), and high-fat diet with Sangguayin Decoction (HFD-SGY, oral dose of 250 mg/kg/d) for 16 weeks. Next generation sequencing was applied for analyzing the gut microbial community of colonic contents. Further, untargeted metabolomic analysis based on LC-MS was used for determining the changes of hepatic metabolites. Hepatic genes expression were measured by quantitative PCR. RESULTS: SGY supplement decreased blood glucose level and glucose intolerance. Illumina MiSeq sequencing revealed that SGY increased Verrucomicrobia phylum, resulting in a bloom of Akkermansia, and eventually upregulated the contents of Lachoclostridium and Roseburia. Additionally, dietary SGY decreased bacteria including Faecalibaculum, and Blautia. Moreover, the hepatic lipid metabolism was notably altered by SGY treatment. The oxidation of glutamione metabolism idecreasees, production of poly-unsaturated fatty acid (PUFA) got significant increase in liver tissue. The reversion of PUFA metabolism by SGY may act through PPARα mediated Fads1 and Fads2 gene expression. The altered metabolites in liver showed intimate correlatship with modified genera. CONCLUSION: Data indicated that SGY reshaped gut microbial structure and improved PUFA metabolism. These functions of SGY may alter hepatic lipid metabolism, conferring preventative effects against high-fat diet induced metabolic syndrome.

[Value of plasma brain natriuretic peptide detection in cardiac function assessment in hemodialysis patients].

OBJECTIVE: To detect plasma brain natriuretic peptide (BNP) changes in hemodialysis patients with chronic renal failure (CRF) and assess the diagnostic value of BNP for cardiac function. METHODS: Plasma BNP concentration was measured in 93 hemodialysis patients with CRF and 52 healthy control subjects. In the 93 patients, echocardiographic examinations were performed to determine the relationship between BNP and cardiac function. RESULTS: The median plasma BNP levels in 52 normal controls were 3.35 pg/ml (1.00-9.73 pg/ml), and 146.5 pg/ml (56.2-546.9 pg/ml) and 90.0 pg/ml (18.3-310.5 pg/ml) in 93 patients before and after hemodialysis, respectively, showing significant difference among those 3 groups (P<0.001). The plasma BNP levels in patients with CRF complicated by heart failure (LVEF<50%) before and after hemodialysis were 686.0 pg/ml (334.5-1319.3 pg/ml) and 248.0 pg/ml (80.3-814.5 pg/ml) respectively, significantly higher than 62.8 pg/ml (22.0-321.6 pg/ml) and 20.7 pg/ml (1.0-200.9 pg/ml) in patients with normal cardiac function (LVEF > or = 50%) (P=0.002). The plasma BNP levels in patients with dilated left ventricle before and after hemodialysis were 609.0 pg/ml (254-1152.0 pg/ml) and 310.0 pg/ml (28.3-839.6 pg/ml) respectively, significantly higher than 62.8 pg/ml (23.2-192.5 pg/ml) and 22.4 pg/ml (1.0-80.7 pg/ml) in patients with normal left ventricle. Multiple linear regression analysis for left ventricular diastolic dimension, LVEF and plasma BNP level before hemodialysis showed that high BNP level was significantly correlated with dilated left ventricle and poor cardiac function (P<0.01). CONCLUSIONS: Plasma BNP levels in hemodialysis patients with CRF are significantly higher than those in healthy controls, and are significantly lowered after hemodialysis but still remain higher than the normal level. Plasma BNP levels in hemodialysis patients with dilated left ventricle or heart failure are significantly higher than those in patients with normal left ventricle or cardiac function, and high plasma BNP level is significantly correlated with dilated left ventricle and poor cardiac function.