Structural Characterization and Immune Activity Screening of Polysaccharides With Different Molecular Weights From Astragali Radix
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SUBMITTER: Li K
PROVIDER: S-EPMC7774520 | biostudies-literature | 2020 Jan
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND: Astragali Radix has been used widely for the treatment of cardiovascular and cerebrovascular diseases, and to enhance endurance and stamina in traditional Chinese medicine (TCM) for over 2000 years. The polysaccharide constituents of Astragali Radix (ARP) are considered as one of the major constituents contributing to the multiple pharmacological effects of this medicinal plant. The purpose of the study is to evaluate the vascular regenerative activities of ARPs in a chemically-induced blood vessel loss model in zebrafish. METHODS: Blood vessel loss was induced in both Tg(fli-1a:EGFP)y1 and Tg(fli-1a:nEGFP)y7 embryos by administration of 300 nM VEGFR tyrosine kinase inhibitor II (VRI) for 3 h at 24 hpf (hour post-fertilization). Then, the blood vessel damaged zebrafish were treated with ARPs for 21 h and 45 h after VRI withdrawal. Morphological changes in intersegmental vessels (ISVs) of zebrafish larvae were observed under the fluorescence microscope and measured quantitatively. The rescue effect of ARPs in the zebrafish models was validated by measuring the relative mRNA expressions of Kdrl, Kdr and Flt-1 using real-time PCR. RESULTS: Two polysaccharide fractions, P4 (50000 D < molecular weight & diameter < 0.1 ?m) and P5 (molecular diameter > 0.1 ?m), isolated from Astragali Radix by ultrafiltration, produced a significant and dose-dependent recovery in VRI-induced blood vessel loss in zebrafish. Furthermore, the down-regulation of Flk-1 and Flt-1 mRNA expression induced by VRI was reversed by treatment with P4. CONCLUSION: The present study demonstrates that P4 isolated from Astragali Radix reduces VRI-induced blood vessel loss in zebrafish. These findings support the hypothesis that polysaccharides are one of the active constituents in Astragali Radix, contributing to its beneficial effect on treatment of diseases associated with a deficiency in angiogenesis.
| S-EPMC3316134 | biostudies-literature
Project description:The molecular weight, the triple-helix conformation, the monosaccharide content, the manner of glycosidic linkages, and the polysaccharide conjugates of polysaccharides all affect bioactivity. The purpose of this study was to determine how different molecular weights affected the bioactivity of the Lycium barbarum polysaccharides (LBPs). By ethanol-graded precipitation and ultrafiltration membrane separation, one oligosaccharide (LBPs-1, 1.912 kDa) and two polysaccharides (LBPs-2, 7.481 kDa; LBPs-3, 46.239 kDa) were obtained from Lycium barbarum. While the major component of LBPs-1 and LBPs-2 was glucose, the main constituents of LBPs-3 were arabinose, galactose, and glucose. LBPs-2 and LBPs-3 exhibited triple-helix conformations, as evidenced by the Congo red experiment and AFM data. Sugar residues of LBPs-2 and LBPs-3 were elucidated by NMR spectra. The polysaccharides (LBPs-2 and LBPs-3) exhibited much higher antioxidant capacities than oligosaccharide (LBPs-1). LBPs-3 showed higher oxygen radical absorbance capacity (ORAC) and superoxide dismutase (SOD) activity than LBPs-2, but a lower capability for scavenging ABTS+ radicals. In zebrafish, LBPs-2 and LBPs-3 boosted the growth of T-lymphocytes and macrophages, enhanced the immunological response, and mitigated the immune damage generated by VTI. In addition to the molecular weight, the results indicated that the biological activities would be the consequence of various aspects, such as the monosaccharide composition ratio, the chemical composition, and the chemical reaction mechanism.
| S-EPMC9867462 | biostudies-literature
Project description:This study investigated the repair effects of three Astragalus polysaccharides (APSs) with different molecular weights (Mws) on injured human renal proximal tubular epithelial (HK-2) cells to reveal the effect of Mw of polysaccharide on cell repair. A damage model was established by injuring HK-2 cells with 2.6 mM oxalate, and APS0, APS1, and APS2 with Mw of 11.03, 4.72, and 2.61 KDa were used to repair the damaged cells. After repair by APSs, the morphology of damaged HK-2 cells gradually returned to normal, the destruction of intercellular junctions recovered, intracellular reactive oxygen species production amount decreased, and their mitochondrial membrane potential increased. In addition, the cell cycle progression gradually normalized, lysosome integrity increased, and cell apoptotic rates obviously declined in the repaired cells. All three APSs could promote the expression of Keap1, Nrf2, SOD1, and CAT. In addition, the expression levels of inflammation markers containing MCP-1 and IL-6 decreased after APS repair. We deduced that APSs exert their repair function by activating the Nrf2-Keap1 signaling pathway and inhibiting inflammation. Among the APSs, APS1 with a moderate Mw provided the strongest repair effect. APSs may have a preventive effect on kidney stones.
| S-EPMC6614371 | biostudies-literature
Project description:The worldwide traditional Chinese medicine (TCM) herbs sales figures have increased considerably to 50 billion US$ (2018). Astragali Radix (AR) is amongst the most often sold TCM herbs; sales in the European Union (EU) need European Medicines Agency (EMA) approval. However, comparisons of characteristic bioactive molecules concentrations in AR from different EU vendors are lacking. This study uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) with standard addition to evaluate the influence of different sample and preparation types and ammonia treatment on bioactive molecules concentrations in AR. We also compare AR samples from different EU-vendors. Astragaloside IV (AG-IV), ononin and calycosin 7-O-β-D-glucoside concentrations were higher in root powder samples when extracted with boiled water than with ultrasonication using 70% methanol. AG-IV content was by far the highest in granulates from vendor 1 (202 ± 35 μg/g) but very low in hydrophilic concentrates from vendor 1 (32 ± 7 μg/g) and granulates from vendor 4 (36 ± 3 μg/g). Ammonia-treatment significantly increased AG-IV concentrations in all samples (e.g., to 536 ± 178 μg/g in vendor 1 granulates). Comparable effects were found for most other bioactive molecules. AG-IV and other bioactive molecules concentrations differed strongly depending on sample types, extraction processes, ammonia treatment-or-not and especially between different vendors samples. Ammonia-treatment is debatable, as it is supposed to convert other astragalosides, to AG-IV. The results indicate that routine quantitative analysis of major bioactive compounds present in AR, helps in quality control of AR and to guarantee the quality of commercial products.
| S-EPMC8263255 | biostudies-literature
Project description:Astragali Radix polysaccharides (APSs) have a wide range of biological activities. Our preliminary experiment showed that APS-Ⅱ (10 kDa) was the main immunologically active component of APSs. However, the characteristic structure related to activity of APS-Ⅱ needs further verification and clarification. In this study, APS-II was degraded by endo α-1,4-glucosidase. The degraded products with different degrees of polymerization [1-3 (P1), 3-6 (P2), 7-14 (P3), and 10-18 (P4)] were obtained using a polyacrylamide gel chromatography column. The structural features of the different products were characterized by HPGPC, monosaccharide composition, Fourier transform infrared spectrum, GC-MS, nuclear magnetic resonance, and UPLC-ESI-QTOF-MS analysis. Specific immune and non-specific immune cell tests were used to identify the most immunogenic fractions of the products. The backbone of P4 was speculated to be α-D-1,4-linked glucans and rich in C2 (25.34%) and C6 (34.54%) branches. Immune screening experiments indicated that the activity of P4 was better than that of APS-II and the other three components. In this research, the relationship between the structure of APS-Ⅱ and the immune activity from the degradation level of polysaccharides was studied, laying a foundation for the quality control and product development of APSs.
| S-EPMC8913491 | biostudies-literature
Project description:According to current research, the primary active ingredients of Radix Astragali (RA), such as saponins, flavonoids, and polysaccharides, play an important role in anti-inflammatory effects. However, the exact molecular mechanism underlying the action was not elucidated to date. Our research attempted to determine the active components in RA and to investigate the interaction between the active components and targets involved in the anti-inflammation activity by network pharmacology and molecular docking. The active components and targets of RA were screened out by TCMSP. Thereafter, through the "anti-inflammation effect" and "inflammation" as the keywords, disease targets were obtained from the GeneCards database. The PPI network was constructed with Cytoscape 3.8.0 software to screen core targets. The GO function and KEGG analysis were enriched and analyzed through the Metascape platform, obtaining the 3-dimensional view of the core targets from the PDB database, and then, performing molecular docking in AutoDock Vina, a heatmap was constructed using the binding free energies in GraphPad Prism 8. The Discovery Studio software was used for docking analysis, and eventually, the docking results were visualized. We also explored the targets and signaling pathways of Astragaloside IV acting on anti-inflammatory effects via constructing compound-disease-target-pathway network. 18 active components and 45 targets of RA were screened out. The main anti-inflammatory active components of RA were quercetin, Astragaloside IV, kaempferol, 7-O-methylisomucronulatol, and formononetin, and the strongly interacting core proteins were TNF, IL6, IL1B, TLR4, CXCL8, CCL2, IL10, VEGFA, and MMP9. The signal pathways mainly involved include Lipid and atherosclerosis, IL-17 signaling pathway, Chagas disease, leishmaniasis, and TNF signaling pathway. Moreover, molecular docking showed that the 2 most active compounds, Astragaloside IV and kaempferol, could efficiently bind with the targets TNF, TLR4, and IL10. Astragaloside IV may play a part in anti-inflammatory effects through pathways such as HIF-1 signaling pathway, Inflammatory bowel disease and Hepatitis B ect. RA exhibits the characteristic of multicomponent and multitarget synergistic effects in exerting anti-inflammatory effects and the effective component of RA is Astragaloside IV, targeting TNF, TLR4, and IL10.
| S-EPMC10476849 | biostudies-literature
Project description:This study aims at investigating the antioxidant activity and repair effect of green tea polysaccharide (TPS) with different molecular weights (Mw) on damaged human kidney proximal tubular epithelial cells (HK-2). Scavenging activities on hydroxyl radical (·OH) and ABTS radical and reducing power of four kinds of TPS with Mw of 10.88 (TPS0), 8.16 (TPS1), 4.82 (TPS2), and 2.31?kDa (TPS3) were detected. A damaged cell model was established using 2.6?mmol/L oxalate to injure HK-2 cells. Then, different concentrations of TPSs were used to repair the damaged cells. Index changes of subcellular organelles of HK-2 cells were detected before and after repair. The four kinds of TPSs possessed radical scavenging activity and reducing power, wherein TPS2 with moderate Mw presented the strongest antioxidant activity. After repair by TPSs, cell morphology of damaged HK-2 cells was gradually restored to normal conditions. Reactive oxygen species production decreased, and mitochondrial membrane potential (??m) of repaired cells increased. Cells of G1 phase arrest were inhibited, and cell proportion in the S phase increased. Lysosome integrity improved, and cell apoptotic rates significantly reduced in the repaired group. The four kinds of TPSs with varying Mw displayed antioxidant activity and repair effect on the mitochondria, lysosomes, and intracellular DNA. TPS2, with moderate Mw, showed the strongest antioxidant activity and repair effect; it may become a potential drug for prevention and treatment of kidney stones.
| S-EPMC6280578 | biostudies-literature
Project description:BACKGROUND:Radix Astragali and Radix Angelicae Sinensis are two herbs that compose Danggui Buxue Tang (an herbal formula for treatment of anemia diseases). In this study, we explored the molecular mechanism and effective targets to immune destruction of bone marrow (BM) cells treated with Radix Astragali, Radix Angelicae Sinensis or a combination of two agents. The potential synergic advantages of two herbs should also be explored. METHODS:The constituents of Radix Astragali and Radix Angelicae Sinensis were analyzed by high performance liquid chromatography-electrospray ionization/mass spectrometer system BM cells were separated from limbs of BALB/c mice, and immune destruction was induced with IFN-?. The percentages of hematopoietic stem cells (HSCs) and CD3+ T cells were detected by flow cytometry. The distribution of T-bet and changes in the combination of SAP and SLAM in BM cells were observed by immunofluorescence. Western blotting was used to assay the expression of key molecules of the eIF2 signaling pathway in BM cells. RESULTS:Seven constituents of Radix Astragali and six constituents of Radix Angelicae Sinensis were identified. The percentages of HSCs increased significantly after treatment with Radix Angelicae Sinensis, especially at high concentrations. The percentages of CD3+ T cells were significantly decreased after Radix Astragali and Radix Angelicae Sinensis treatment. However, the synergistic function of two-herb combinations was superior to that of the individual herbs alone. The distribution of T-bet in BM cells was decreased significantly after Radix Angelicae Sinensis treatment. The number of SLAM/SAP double-stained cells was increased significantly after Radix Astragali treatment at low concentrations. The phosphorylation levels of eIF2? were also reduced after Radix Astragali and Radix Angelicae Sinensis treatment. CONCLUSIONS:Radix Astragali and Radix Angelicae Sinensis could intervene in the immunologic balance of T lymphocytes, inhibit the apoptosis of BM cells induced by immune attack, restore the balance of the T cell immune response network and recover the hematopoietic function of HSCs. The synergistic effects of Radix Astragali and Radix Angelicae Sinensis were superior to those of each herb alone.
| S-EPMC6902408 | biostudies-literature
Project description:The structure⁻activity relationships and repair mechanism of six low-molecular-weight seaweed polysaccharides (SPSs) on oxalate-induced damaged human kidney proximal tubular epithelial cells (HK-2) were investigated. These SPSs included Laminaria japonica polysaccharide, degraded Porphyra yezoensis polysaccharide, degraded Gracilaria lemaneiformis polysaccharide, degraded Sargassum fusiforme polysaccharide, Eucheuma gelatinae polysaccharide, and degraded Undaria pinnatifida polysaccharide. These SPSs have a narrow difference of molecular weight (from 1968 to 4020 Da) after degradation by controlling H₂O₂ concentration. The sulfate group (⁻SO₃H) content of the six SPSs was 21.7%, 17.9%, 13.3%, 8.2%, 7.0%, and 5.5%, respectively, and the ⁻COOH contents varied between 1.0% to 1.7%. After degradation, no significant difference was observed in the contents of characteristic ⁻SO₃H and ⁻COOH groups of polysaccharides. The repair effect of polysaccharides was determined using cell-viability test by CCK-8 assay and cell-morphology test by hematoxylin-eosin staining. The results revealed that these SPSs within 0.1⁻100 μg/mL did not express cytotoxicity in HK-2 cells, and each polysaccharide had a repair effect on oxalate-induced damaged HK-2 cells. Simultaneously, the content of polysaccharide ⁻SO₃H was positively correlated with repair ability. Furthermore, the low-molecular-weight degraded polysaccharides showed better repair activity on damaged HK-2 cells than their undegraded counterpart. Our results can provide reference for inhibiting the formation of kidney stones and for developing original anti-stone polysaccharide drugs.
| S-EPMC6431945 | biostudies-literature
Project description:BackgroundAstragali Radix-Curcumae Rhizoma (ARCR), a classic drug pair, has been widely used for the treatment of gastric intraepithelial neoplasia (GIN) in China. However, the underlying mechanisms of this drug pair are still unknown. Thus, elucidating the molecular mechanism of ARCR for treating GIN is imperative.MethodsThe active components and targets of ARCR were determined from the TCMSP database, and the differentially expressed genes related to GIN were identified from the GSE130823 dataset. The protein-protein interaction (PPI) network and ARCR-active component-target-pathway network were constructed by STRING 11.0 and Cytoscape 3.7.2, respectively. In addition, a receiver operating characteristic curve (ROC) was conducted to verify the key targets, and enrichment analyses were performed using R software. Molecular docking was carried out to test the binding capacity between core active components and key targets.Results31 active components were obtained from ARCR, among which 22 were hit by the 51 targets associated with GIN. Gene Ontology (GO) functional enrichment analysis showed that biological process (BP), molecular function (MF), and cellular component (CC) were most significantly enriched in response to a drug, catecholamine binding, and apical part of the cell, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated ARCR against GIN through regulation of neuroactive ligand-receptor interaction, nitrogen metabolism, calcium signaling pathway, chemical carcinogenesis-receptor activation, drug metabolism, gap junction, and cancers. In the PPI network, 15 potential targets were identified, of which nine key targets were proven to have higher diagnostic values in ROC. Molecular docking revealed a good binding affinity of active components (quercetin, bisdemethoxycurcumin, and kaempferol) with the corresponding targets (CYP3A4, CYP1A1, HMOX1, DRD2, DPP4, ADRA2A, ADRA2C, NR1I2, and LGALS4).ConclusionThis study revealed the active components and molecular mechanism by which ARCR treatment is effective against GIN through regulating multipathway, such as neuroactive ligand-receptor interaction, nitrogen metabolism, and calcium signaling pathway.
| S-EPMC8505068 | biostudies-literature