Structural elucidation and osteogenic activity of a novel heteropolysaccharide from Alhagi pseudalhagi

Degradation of Angelica sinensis polysaccharide: Structures and protective activities against ethanol-induced acute liver injury

Angelica sinensis polysaccharide (ASP) possesses diverse bioactivities; however, its metabolic fate following oral administration remains poorly understood. To intuitively determine its intestinal digestion behavior after oral administration, ASP was labeled with fluorescein, and it was found to accumulate and be degraded in the cecum and colon. Therefore, we investigated the in vitro enzymatic degradation behavior and identified the products. The results showed that ASP could be degraded into fragments with molecular weights similar to those of the fragments observed in vivo. Structural characterization revealed that ASP is a highly branched acid heteropolysaccharide with AG type II domains, and its backbone is predominantly composed of 1,3-Galp, →3,6)-Galp-(1→6)-Galp-(1→, 1,4-Manp, 1,4-Rhap, 1,3-Glcp, 1,2,3,4-Galp, 1,3,4,6-Galp, 1,3,4-GalAp and 1,4-GlcAp, with branches of Araf, Glcp and Galp. In addition, the high molecular weight enzymatic degradation products (ASP H) maintained a backbone structure almost identical to that of ASP, but exhibited only partial branch changes. Then, the results of ethanol-induced acute liver injury experiments revealed that ASP and ASP H reduced the expression of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and malondialdehyde (MDA) and increased the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) levels, thereby relieving ethanol-induced acute liver injury.

Potential osteoporosis-blocker Sparassis crispa polysaccharide: Isolation, purification and structure elucidation

This study aimed to investigate the structural characterization of water-soluble polysaccharides from Sparassis crispa and their effects on the proliferation and differentiation of mouse osteoblasts. Three fractions (F-1, F-2, and F-3) were obtained from crude polysaccharides by a DEAE-52 cellulose column. The main fraction (F-1) was further purified by polysaccharide gel purification systems to obtain purified water-soluble Sparassis crispa polysaccharide (SCPS). The chemical structure of SCPS was analyzed by gas chromatography, Fourier transform infrared spectroscopy, methylation analysis, and nuclear magnetic resonance spectroscopy. The monosaccharide compositional analysis revealed that SCPS consisted of fucose, arabinose, galactose, glucose, xylose, mannose, ribose, galacturonic acid, glucuronic acid, and mannuronic acid in a molar ratio of 17.37:1.94:25.52:30.83:1.14:0.30:4.98:2.87:2.65. Moreover, the backbone of SCPS was composed of →3)-β-d-Glcp-(1→4)-β-d-Glcp-(1→, with side chains attached to the backbone at the O-6 positions through the →3,6)-β-d-Glcp-(1→ linkage. The in vitro experiments were conducted to investigate the effects of SCPS on the proliferation and differentiation of mouse osteoblasts. The results showed that SCPS significantly enhanced the proliferation and differentiation of mouse osteoblasts, indicating their potential as a pharmaceutical agent for promoting osteoblast proliferation and differentiation.

Structural Characterization and Anticomplement Activity of an Acidic Heteropolysaccharide from Lysimachia christinae Hance

A novel acidic heteropolysaccharide (LCP-90-1) was isolated and purified from a traditional "heat-clearing" Chinese medicine, Lysimachia christinae Hance. LCP-90-1 (Mw, 20.65 kDa) was composed of Man, Rha, GlcA, Glc, Gal, and Ara, with relative molar ratios of 1.00: 3.00: 11.62: 1.31: 1.64: 5.24. The backbone consisted of 1,4-α-D-GlcpA, 1,4-α-D-Glcp, 1,4-β-L-Rhap, and 1,3,5-α-L-Araf, with three branches of β-D-Galp-(1 → 4)-β-L-Rhap-(1→, α-L-Araf-(1→ and α-D-Manp-(1→ attached to the C-5 position of 1,3,5-α-L-Araf. LCP-90-1 exhibited potent anticomplement activity (CH50: 135.01 ± 0.68 µg/mL) in vitro, which was significantly enhanced with increased glucuronic acid (GlcA) content in its degradation production (LCP-90-1-A, CH50: 28.26 ± 0.39 µg/mL). However, both LCP-90-1 and LCP90-1-A were inactivated after reduction or complete acid hydrolysis. These observations indicated the important role of GlcA in LCP-90-1 and associated derivatives with respect to anticomplement activity. Similarly, compared with LCP-90-1, the antioxidant activity of LCP-90-1-A was also enhanced. Thus, polysaccharides with a high content of GlcA might be important and effective substances of L. christinae.

Curculigo orchioides polysaccharide COP70-1 stimulates osteogenic differentiation of MC3T3-E1 cells by activating the BMP and Wnt signaling pathways

The crude polysaccharide CO70 isolated from Curculigo orchioides could alleviate ovariectomy-induced osteoporosis in rats. To clarify the bioactive components, a new heteropolysaccharide (COP70-1) was purified from CO70 in this study, which was consisted of β-D-Manp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Manp-(1→, →3,4)-β-D-Manp-(1→, →4,6)-β-D-Manp-(1→, and →4,6)-α-D-Galp-(1→. COP70-1 significantly promoted the osteoblastic differentiation of MC3T3-E1 cells through improving alkaline phosphatase activity, the deposition of calcium as well as up-regulating the expression of osteogenic markers (RUNX2, OSX, BSP, OCN, and OPN). Furthermore, COP70-1 stimulated the expression of critical transcription factors of the BMP and Wnt pathways, including BMP2, p-SMAD1, active-β-catenin, p-GSK-3β, and LEF-1. In addition, LDN (BMP pathway inhibitor) and DKK-1 (Wnt pathway inhibitor) suppressed the COP70-1-induced osteogenic differentiation of MC3T3-E1 cells. Therefore, COP70-1 was one of the bioactive constituents of C. orchioides for targeting osteoblasts to treat osteoporosis by triggering BMP/Smad and Wnt/β-catenin pathways.

Extraction, purification, structural characterization, and hepatoprotective effect of the polysaccharide from purple sweet potato

BACKGROUND

Purple sweet potato Ipomoea batatas (L.) has long been used as a medicine and a food. It contains various bioactive substances such as polysaccharides, anthocyanins, and flavonoids. Purple sweet potato polysaccharides are known to have anti-oxidant, anti-tumor, and immunomodulatory functions. Nevertheless, studies on the structural characterization of purple sweet potato polysaccharides and their ability to prevent non-alcoholic fatty liver disease (NAFLD) have rarely been reported.

RESULTS

A novel polysaccharide (PSPP-A) was extracted and isolated from purple sweet potato, and its structural characteristics and preventive effects on NAFLD were investigated. The results indicated that PSPP-A was composed of l-rhamnose, d-arabinose, d-galactose, d-glucose, and d-glucuronic acid with molar ratios of 1.89:8.45:1.95:1.13:1. Its molecular weight was 2.63 × 10³  kDa. Methylation and nuclear magnetic resonance (NMR) analysis indicated that the glycosidic linkages were →3)-α-L-Araf-(1→, α-L-Araf-(1→, →2,4)-α-L-Rhap-(1→, 4-O-Me-β-D-GlcAp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Galp-(1→, and →6)-β-D-Galp-(1→. Scanning electron microscopy (SEM) indicated that the structure of PSPP-A was irregular. Subsequently, the protective effect of PSPP-A on NAFLD was investigated. The results indicated that bodyweight, liver index, and triglyceride (TG), total cholesterol (TC), aspartate transaminase (AST), and alanine transaminase (ALT) content were significantly reduced by intervention of purple sweet potato polysaccharide-A (PSPP-A) compared with the - high-fat diet group. Liver histopathological analysis indicated that PSPP-A attenuated irregular hepatocyte patterns and excessive lipid vacuoles.

CONCLUSIONS

The novel polysaccharide, PSPP-A, mainly contains arabinose, which has certain preventive effects on NAFLD. This study provides a theoretical basis for further elucidating the hepatoprotective effect of purple sweet potatoes as a functional food. © 2022 Society of Chemical Industry.

Structural elucidation and anti-neuroinflammatory activity of Polygala tenuifolia polysaccharide

Polygala tenuifolia is extensively used to treat amnesia in traditional Chinese medicine, and pharmacological studies have reported the beneficial effects of P. tenuifolia on intelligence and cognition. In the present study, the crude polysaccharide alkali-extracted from P. tenuifolia roots (PTB) inhibited lipopolysaccharide-induced microglia/astrocyte activation and significantly improved the learning and memory ability of Alzheimer's disease (AD) rats. To determine its bioactive components, a heteropolysaccharide (PTBP-1-3) was isolated from PTB. Structural analysis showed that PTBP-1-3 was composed of α-L-Araf-(1 → ， → 3)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, β-D-Xylp-(1→, →2,3,4)-β-D-Xylp-(1→, α-L-Rhap-(1→, β-D-Galp-(1→, →4)-α-D-Galp-(1→, →6)-α-D-Galp-(1→, →6)-α-D-Glcp-(1→, →3,6)-α-D-Glcp-(1→, →6)-α-D-Manp-(1→, and →2,4)-β-D-Manp-(1 → residues. PTBP-1-3 decreased the production of NO, TNF-α, and IL-1β in lipopolysaccharide-activated BV2 microglia cells in a manner similar to that of minocycline. In conclusion, PTBP-1-3 exhibited a potent inhibitory effect on neuroinflammation, and could be one of the bioactive ingredients in PTB for anti-neuroinflammation. PTB and PTBP-1-3 may be potential therapeutic agents for the treatment of AD.

Structural characterization of a mannoglucan polysaccharide from Dendrobium huoshanense and evaluation of its osteogenesis promotion activities

Dendrobium huoshanense, a valuable traditional Chinese herb, is widely used to prolong life in China. Our study aims to characterize the structure and osteogenesis-promotion effects of a heteropolysaccharide component isolated from Dendrobium huoshanense (DHPW1). The structure of DHPW1 was characterized using gas chromatography-mass spectrometry and nuclear magnetic resonance, while its osteogenic activity was evaluated using MG-63 cells and zebrafish skulls. The results showed that the molecular weight of DHPW1 was 230 kDa and it was mainly composed of mannose and glucose. In addition, the DHPW1 backbone consisted of (1 → 4)-linked-β-D-Mannopyranosyl and (1 → 4)-linked-β-d-Glucopyranosyl. Furthermore, DHPW1 significantly increased ALP activity and mineralized nodule formation in MG-63 cells. DHPW1 in zebrafish skull models significantly enhanced the relative fluorescence intensity of bone mass and increased the degree of bone mineralization. These results suggested that the DHPW1 component in D. huoshanense has potential to promote osteogenesis.

Structural characterization and anti-osteoporosis activity of two polysaccharides extracted from the rhizome of Curculigo orchioides

Curculigo orchioides is widely used to treat osteoporosis in China. In this study, we identified the active substances in the crude polysaccharide (CO50) from C. orchioides that had anti-osteoporosis activity in vivo. Two polysaccharides, COP50-1 and COP50-4, were purified from CO50. Based on structural analysis, COP50-1 was composed of α-D-Glcp-(1→, β-D-Galp-(1→, →4)-α-D-Glcp-(1→, →3,4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, →4,6)-β-D-Manp-(1→, whereas COP50-4 was composed of α-L-Araf-(1→, →2)-α-L-Rhap-(1→, β-D-Manp-(1→, α-D-Galp-(1→, →2,4)-α-L-Rhap-(1→, →2)-β-D-Manp-(1→, →4)-α-D-GlcAp-(1→, →3)-α-D-GalAp-(1→, →4,6)-α-D-Galp-(1→, →2,3,6)-β-D-Manp-(1→, →2,3,5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→ and →3)-α-D-Galp-(1→. Pharmacological assessment revealed that COP50-1 had no obvious osteogenic activity. However, COP50-4 (0.5 μM) significantly enhanced the differentiation and mineralization of osteoblasts in vitro. Moreover, the effect of COP50-4 was greater than that of 17β-estradiol. Therefore, COP50-4 may be an effective component of CO50 that has great potential for development as an alternative drug for the treatment of osteoporosis.

Isolation, Structural Characterization and Macrophage Activation Activity of an Acidic Polysaccharide from Raspberry Pulp

The discovery of safe and effective plant polysaccharides with immunomodulatory effects has become a research hotspot. Raspberry is an essential commercial fruit and is widely distributed, cultivated, and consumed worldwide. In the present study, a homogeneous acidic polysaccharide (RPP-2a), with a weight-average molecular weight (Mw) of 55582 Da, was isolated from the pulp of raspberries through DEAE-Sepharose Fast Flow and Sephadex G-200 chromatography. RPP-2a consisted of rhamnose, arabinose, galactose, glucose, xylose, galacturonic acid and glucuronic acid, with a molar ratio of 15.4:9.6:7.6:3.2:9.1:54.3:0.8. The results of Fourier transform infrared spectroscopy (FT-IR), gas chromatography-mass spectrometer (GC-MS), 1D-, and 2D-nuclear magnetic resonance (NMR) analyses suggested that the backbone of RPP-2a was primarily composed of →2)-α-L-Rhap-(1→, →2,4)-α-L-Rhap-(1→, →4)-α-D-GalAp-(1→, and →3,4)-α-D-Glcp-(1→ sugar moieties, with side chains of α-L-Araf-(1→, α-L-Arap-(1→, and β-D-Galp-(1→3)-β-D-Galp-(1→ residues linked to the O-4 band of rhamnose and O-3 band of glucose residues. Furthermore, RPP-2a exhibited significant macrophage activation activity by increasing the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and the expression of inducible nitric oxide synthase (iNOS) and cytokines at the transcriptional level in RAW264.7 cells. Overall, the results indicate that RPP-2a can be utilized as a potential natural immune-enhancing agent.

Anti-Osteoporotic Effects of Commiphora Myrrha and Its Poly-Saccharide via Osteoclastogenesis Inhibition

In traditional oriental medicines, Commiphora myrrha and its resinous exudate (i.e., myrrh) are used as herbal remedies to treat various inflammatory and metabolic disorders. Until now, C. myrrha-derived herbal products are considered useful source for bioactive compounds to manage numerous human diseases. This study investigated the effects of water extract of C. myrrha resin (WCM) and its polysaccharide (WCM-PE) on modulatory effects of osteoclast differentiation and/or ovariectomized-induced bone loss. Oral administration of WCM (200 and 500 mg/kg/day for four weeks) notably decreased trabecular bone loss and lipid accumulation in the bone marrow cavity. WCM and WCM-PE dose-dependently inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and suppressed RANKL-mediated overexpression of c-Fos and nuclear factor of activated T cells, cytoplasmic 1, thereby downregulating osteoclast-specific gene (Atp6v0d2, DC-STAMP and cathepsin K) expression. Thus, our results suggest that WCM and WCM-PE are promising nutraceutical candidates for the management of osteoporosis in postmenopausal women.

The structure, conformation, and hypoglycemic activity of a novel heteropolysaccharide from the blackberry fruit

A novel heteropolysaccharide fraction (BBP-24-3) with a relative molecular weight of 145.1 kDa was isolated from blackberry fruits. The BBP-24-3 was mainly composed of arabinose, glucose, and galacturonic acid with a ratio of 5.30 : 3.60 : 91.10 mol%. Structural analysis showed that BBP-24-3 possessed a 1,6-linked β-d-Glcp, 1, 2, 3, 5 linked α-l-Araf, and 1, 4 linked α-d-GalpA backbone with branches substituted at the C-2 and C-5 positions of arabinose units, which included 1, 2, 3, 4 linked β-d-Glcp and T-linked β-d-GalpA. The conformation analysis indicated that BBP-24-3 exhibited a solid spherical structure with a uniform distribution in 0.1 M NaCl solution. The BBP-24-3 exhibited excellent α-glucosidase inhibitory activity with an IC50 value of 3.70 mg mL-1, which was due to the structural change, including α-helix and random coil of α-glucosidase caused by BBP-24-3. The current work suggests the potential utilization of BBP-24-3 as an α-glucosidase inhibitor in healthy food for reducing the postprandial blood glucose level.