Structural characteristics of water-soluble polysaccharides from Heracleum sosnowskyi Manden

Characterization and anti-aging activities of polysaccharide from Rana dybowskii Guenther

Introduction: Rana dybowskii Guenther (RDG), as a traditional Chinese medicine, has been shown to have antioxidant effects. However, studies on the anti-aging effect of RDG are still limited. Methods: In this study, we prepared polysaccharides from the skin of RDG (RDGP) by hot water extraction, alcohol precipitation, ion-exchange chromatography and gel chromatography. The proteins were removed using the Sevage method in combination with an enzymatic method. The structural features were analyzed using high-performance gel permeation chromatography, β-elimination reaction and Fourier transform infrared spectra. The anti-aging effect of RDGP was investigated by using D-Gal to establish an aging model in mice, and pathological changes in the hippocampus were observed under a microscope. Results: We obtained the crude polysaccharide DGP from the skin of RDG, with a yield of 61.8%. The free protein was then removed by the Sevage method to obtain DGPI and deproteinated by enzymatic hydrolysis combined with the Sevage method to further remove the bound protein to obtain the high-purity polysaccharide DGPII. Then, DGPIa (1.03 × 105 Da) and DGPIIa (8.42 × 104 Da) were obtained by gel chromatography, monosaccharide composition analysis showed that they were composed of Man, GlcA, GalNAc, Glc, Gal, Fuc with molar ratios of 1: 4.22 : 1.55: 0.18 : 8.05: 0.83 and 0.74 : 1.78: 1: 0.28: 5.37 : 0.36, respectively. The results of the β-elimination reaction indicated the presence of O-glycopeptide bonds in DGPIa. The Morris water maze test indicated that mice treated with DGPIIa exhibited a significantly shorter escape latency and increased time spent in the target quadrant as well as an increase in the number of times they traversed the platform. Pathologic damage to the hippocampus was alleviated in brain tissue stained with hematoxylin-eosin. In addition, DGPIIa enhanced the activities of SOD, CAT, and GSH-Px and inhibited the level of MDA in the serum and brain tissues of aging mice. Discussion: These results suggest that RDGP has potential as a natural antioxidant and provide useful scientific information for anti-aging research.

Structural characterization of polysaccharides from Geranium sanguineum L. and their immunomodulatory effects in response to inflammatory agents

ETHNOPHARMACOLOGICAL RELEVANCE

Geranium sanguineum L. is used for treatment of inflammations, anemia, malignant diseases of the blood-forming organs, diarrhea, respiratory infections, etc. Only flavonoids in root extracts have been elucidated as immunostimulating and anti-inflammatory compounds, and polysaccharides in the herb have not been examined.

AIM OF THE STUDY

to compare the chemical features of polysaccharide complexes (PSCs) from leaves (GSL-PSC) and roots (GSR-PSC) of G. sanguineum, as well as their immunomodulatory activities on leukocytes after inflammation, and effects on the growth of different bacteria.

MATERIALS AND METHODS

The samples were isolated by water extraction and their structural features were studied by 2D NMR spectroscopy. The stimulatory effects of both PSCs on human leukocytes were analyzed with flow cytometry. Their suppressive activities on the oxidative burst in blood and derived neutrophils against opsonized zymosan and phorbol myristate acetate were investigated. The effects of the samples on viability, NO and interleukin 6 (IL-6) syntheses in RAW264.7 cells after inflammation with lipopolysaccharides (LPS) were tested. The prebiotic and anti-biofilm activities of the PSCs were evaluated.

RESULTS

The total carbohydrate content in the samples was significant (73.6-76.8%). GSL-PSC contained pectins, which were rich in homogalacturonan (HG), and smaller amounts of rhamnogalacturonan (RG) type I, decorated by 1,5-α-L-Araf, 1,4- and 1,6-β-D-Galp chains. GSR-PSC contained starch, followed by pectins with lower HG content and more RG-I regions, substituted by 1 → 3,5-α-L-arabinans and 1 → 3,6-β-D-galactans. GSL-PSC and GSR-PSC (200 μg/mL) increased monocyte and granulocyte cell counts, but GSR-PSC also elevated T helper and B cell levels in a normal and activated state. GSR-PSC triggered a dose-dependent (50-200 μg/mL) oxidative burst in blood, but alleviated it after inflammation even in blood-derived neutrophils. It was free of LPS, and activated NO and IL-6 productions in RAW264.7 cells better than GSL-PSC, without affecting their viability. Both PSCs (2.0%, w/v) stimulated probiotic co-cultures between Clostridium beijerinckii strains and Lactobacillus sp. ZK9, and inhibited the growth and biofilm formation of Escherichia coli, Streptococcus mutans and Salmonella enterica.

CONCLUSIONS

The PSs in G. sanguineum could be involved in the stimulatory effects on blood-forming organs and anti-inflammatory action of aqueous root extracts in case of infections. These PSs should be included in synbiotic foods to support the treatment of inflammations and infections in the gut.

Chemical characteristics and significant antitussive effect of the Erigeron canadensis polyphenolic polysaccharide-protein complex

ETHNOPHARMACOLOGICAL RELEVANCE

Erigeron canadensis has been used in traditional medicine to treat a variety of respiratory diseases, including acute upper and lower respiratory tract infections and cough-related asthma. There is as yet no relevant experimental or clinical study in the scientific literature evaluating the efficacy of plants in these disorders.

AIM OF THE STUDY

To investigate the active ingredients in Erigeron canadensis, a complex isolated from flowering parts of a plant was tested for airway defense reflexes, in particular for cough reflexes and airway reactivity. Both were experimentally induced by a chemical irritant that simulated the inflammatory conditions of their formation.

MATERIAL AND METHODS

The polyphenolic polysaccharide-protein (PPP) complex was isolated from the flowering parts of Erigeron canadensis by hot alkaline extraction and a multi-stage purification process. The antitussive activity was confirmed as a decrease in the number of citric acid-induced coughs and the bronchodilator effect was verified as a decrease in specific airway resistance (sRaw) in conscious guinea pigs.

RESULTS

The dark brown Erigeron complex with a molecular weight of 38,000 g/mol contained phenolics (13.2% wt%), proteins (16.3% wt%), and uronic acids (6.3% wt%). The neutral carbohydrate part of Erigeron consisted mainly of xylose (12.1 wt%), glucose (13.3 wt%), arabinose (24.1 wt%), and galactose (41.0 wt%) residues. Arabinogalactan and 4-OMe-glucuronoxylan have been found to be the major polysaccharides in the Erigeron complex. Using a method of chemically-induced cough reflex and guinea pigs test system the Erigeron complex exhibited statistically significant, the dose-dependent antitussive activity, which was similar to that of the centrally-acting opioid agonist codeine.

CONCLUSION

Pharmacological tests have revealed a new pharmacodynamic effect of the Erigeron complex, namely an antitussive effect. Its activity was most pronounced in comparison with all previously tested compounds from other medicinal plants and approached the effect of codeine, the most potent antitussive used in clinical practice. The results provide the scientific basis for the application of this herb in traditional medicine.

Plants arabinogalactans: From structures to physico-chemical and biological properties

Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or chemically bound to pectin rhamnogalactan. Type I with predominantly β-d-(1 → 4)-galactan and type II with β-d-(1 → 3) and/or (1 → 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.

Structural characterization of anticoagulant and antithrombotic polysaccharides isolated from Caesalpinia ferrea stem barks

This study aimed to isolate, characterize chemical-structurally and evaluate the effects of polysaccharides from Caesalpinia (Libidibia) ferrea stem barks in the haemostatic system. The deproteinated-polysaccharide extract (PE-Cf) after being fractionated by ion exchange chromatography-DEAE-cellulose resulted in three fractions (FI, FII, FIII) containing total carbohydrates (14.3-38%), including uronic acid (5-16%), and polyphenols (0.94-1.7 mg/g GAE). The polysaccharide fractions presented polydisperse profile in polyacrylamide gel electrophoresis (detected by Stains-All) and molecular masses (9.5 × 10⁴ Da-1.5 × 10⁵ Da) identified by gel permeation chromatography. FT-IR showed absorption bands (1630 cm^-1, 1396-1331 cm^-1), indicative of uronic acid, and a band at 1071 cm^-1, typical of COO^- groups of galacturonic acid. The NMR spectra of C. ferrea polysaccharides revealed a central core composed mainly by 5-linked α-Araf and minority components as α-Rhap and α-GalAp. UV spectra of fractions revealed discrete shoulders at 269-275 nm, characteristic of polyphenolic compounds. In vitro, polysaccharides inhibited the intrinsic and/or common coagulation pathway (aPTT test) (2.0-3.7 fold) and the platelet aggregation induced by 3 μM adenosine diphosphate (25-48%) and 5 μg/mL collagen (24%), but not that induced by arachidonic acid. In vivo, the polysaccharides inhibited (36-69%) venous thrombosis induced by hypercoagulability and stasis, showing discrete hemorrhagic effect. In conclusion, the polysaccharides of C. ferrea barks, containing arabinose, galactose, rhamnose and uronic acid, possess anticoagulant, antiplatelet and antithrombotic properties of low hemorrhagic risk, suggesting potential applicability in thromboembolic disorders.

Polysaccharide composition of an anticoagulant fraction from the aqueous extract of Marsypianthes chamaedrys (Lamiaceae)

Marsypianthes chamaedrys (Lamiaceae) is a medicinal plant popularly used against envenomation by snakebite. Pharmacological studies have shown that extracts of M. chamaedrys have antiophidic, anti-inflammatory and anticoagulant properties, supporting the ethnopharmacological use. In this study, an aqueous extract of aerial parts of M. chamaedrys showed anticoagulant activity in the activated partial thromboplastin time assay (0.54 IU/mg). The bioassay-guided fractionation using ethanol precipitation and gel filtration chromatography on Sephadex G-50 and Sephadex G-25 resulted in a water-soluble fraction with increased anticoagulant activity (Fraction F2-A; 2.94 IU/mg). A positive correlation was found between the amount of uronic acids and the anticoagulant potential of the active samples. Chemical and spectroscopic analyses indicated that F2-A contained homogalacturonan, type I rhamnogalacturonan, type II arabinogalactan and α-glucan. UV and FT-IR spectra indicated the possible presence of ferulic acid. Pectic polysaccharides and type II arabinogalactans may be contributing to the anticoagulant activity of the aqueous extract of M. chamaedrys in the APTT assay.

A novel polysaccharide from Malus halliana Koehne with coagulant activity

A novel polysaccharide in Malus halliana Koehne, named MHP-W, was isolated and purified by DEAE-52 cellulose and Sephadex G-100 columns. Structural features were identified by high performance size-exclusion chromatography (HPSEC), fourier transform infrared (FT-IR) spectrometer, gas chromatography (GC) and (1D & 2D) NMR Spectroscopy. Structural characterization showed that the molecular weight of MHP-W was 353 kDa composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 2.59: 0.15: 0.23: 0.25: 9.70. The existence of β-glycosidic bond between the sugar units was confirmed by FT-IR and NMR spectroscopy. The effects of MHP-W on active part thrombin time (APTT), protothrombin time (PT), thrombin time (TT), and fibrinogen (FIB) were screened by a cell-based coagulation activity model. MHP-W could significantly shorten TT (p < 0.001) and increase FIB (p < 0.05) as compared with the control group. The results showed that MHP-W promoted bloodclotting through endogenous and exogenous coagulation pathways as well as increasing fibrinogen content, which indicated that MHP-W had procoagulant activities in vitro.

Structural characterization and in vitro antitumor activity of A polysaccharide from Artemisia annua L. (Huang Huahao)

One water-soluble polysaccharide (AAP), with a molecular weight of 6.3 × 104 Da, was isolated from Artemisia annua L. Structrual analysis indicated that AAP was found to be a 1, 3-α-linked and 1, 3, 6-α-linked Glcp backbone, with a branch of 1, 6-α-linked Glcp and terminal 1-linked-L-Rhap along the main chain in a ratio of 1: 1: 1: 1. MTT assay showed that AAP reduced the cell viability of HepG2 cells in a concentration-dependent manner. DAPI staining and Flow cytometric analysis revealed that AAP suppressed cells proliferation, not most at least via inducing p65-dependent mitochondrial signaling pathway, as evidenced by more activation of caspase-3 and -9, down-regulation of Bcl-2 protein, up-regulation of Bax protein and release of cytochrome c from mitochondria into cytosol, as well as suppression of the nuclear factor-κB (NF-κB) p65. These data confirmed AAP inhibits HepG2 cell growth via inducing caspase-dependent mitochondrial apoptosis and inhibition of NF-κB p65.

Structural characterization and anti-A549 lung cancer cells bioactivity of a polysaccharide from Houttuynia cordata

A water-soluble pectic polysaccharide HCA4S1 was isolated from Houttuynia cordata and purified by DEAE Cellulose and Sephacryl S-300 column. HCA4S1 with an average molecular weight of 21.7 kDa mainly consisted of rhamnose, galacturonic acid, galactose, and arabinose. By using partial acid hydrolysis, methylation analysis, and NMR spectra, the structure of this polysaccharide is found to have a backbone consisting of 1,4-linked α‑d‑GalA and 1,2,4-linked α‑l‑Rha. The latter was substituted at C-4 position by 1,4 linked, 1,6-linked β‑Galp, or Teminal linked β‑Gal. Bioactivity test showed that this polysaccharide might inhibit the proliferation of A549 lung cancer cell by inducing cell cycle arrest and apoptosis. The expression of cleaved caspase 3 and cyclinB1 was observed to be upregulated after the treatment with this polysaccharide. Collectively, these results suggest that the pectin HCA4S1 from Houttuynia cordata is of potential value in the treatment of lung cancer, though the underlying mechanisms remain to be further confirmed.

Structural characterization of a polysaccharide from the flower buds of Tussilago farfara, and its effect on proliferation and apoptosis of A549 human non-small lung cancer cell line

In present study, we purified a polysaccharide, TFPB1, from the flower buds of Tussilago farfara using DEAE-cellulose 52 anion-exchange and Sephacryl S-300 HR gel filtration chromatography. TFPB1 was a homogeneous polysaccharide with a molecular weight of 37.8kDa and composed of rhamnose, galacturonic acid, glucose, galactose, and arabinose, in a ratio of 13:13:1:7:12. Methylation and NMR results demonstrated that TFPB1 contained a rhamnogalacturonan I backbone consisting of a repeat disaccharide unit →4)-α-_D-GalAp-(1→2)-α-_L-Rhap-(1→, substituted by various type II arabinogalactan branches including terminal galactose, (1→3)-β-_D-galactan and (1→5)-α-_L-arabinan, attached to the O-4 of (1→2)-α-_L-Rhap. TFPB1 was found to inhibit cell proliferation of A549 cells and induce cell apoptosis in vitro. Furthermore, TFPB1 downregulated the phosphorylation of Akt, and upregulated caspase-3, Fas, FasL, and Bax expression, but downregulated Bcl-2 expression. Therefore, TFPB1 exhibited anti-proliferative and anti-apoptotic effect partly depending on the suppression of Akt signaling pathway. These findings provided us a potential chemotherapeutic strategy for the treatment of human non-small cell lung cancer.

Structure characterization of two novel polysaccharides isolated from the spikes of Prunella vulgaris and their anticomplement activities

ETHNOPHARMACOLOGICAL RELEVANCE

The spikes of Prunella vulgaris have long been used as a traditional Chinese medicine to treat various inflammation-related diseases. The aim of this study was to isolate and characterize homogenous polysaccharides from this herb and to evaluate their anticomplement activity.

MATERIALS AND METHODS

Anticomplement activity-guided fractionation of the hot water extract of P. vulgaris was performed by DEAE-cellulose and size-exclusion chromatography, yielding two homogeneous polysaccharides PW-PS1 and PW-PS2. The homogeneity, molecular weight, monosaccharide composition and linkage of the two polysaccharides were determined in addition to other chemical characterizations. The anticomplement activity of the polysaccharides was evaluated and expressed as 50% hemolytic inhibition concentration through the classical pathway (CH₅₀ value) and alternative pathway (AP₅₀ value). The preliminary mechanism for the complement activation cascade was also assessed.

RESULTS

PW-PS1 and PW-PS2 were both branched acidic polysaccharides. PW-PS1 was composed of Ara, Xyl, and 4-methoxy-Glc A in a ratio of 1.0: 2.6: 0.8. The main linkages of the sugar residues of PW-PS1 included terminal β-d-Xylp, 1,4-linked β-d-Xylp, 1,3-linked α-d-Arap, 1,3,5-linked α-d-Arap, and terminal 4-methoxy-α-d-Glcp A. PW-PS2 was composed of Rha, Ara, Xyl, Gal, and Gal A in a ratio of 0.6: 1.0: 1.3: 1.8: 3.4. The main linkages between the sugar residues of PW-PS2 included terminal Araf, 1,4-linked β-d-Xylp, 1,3-linked α-d-Rhap, terminal α-d-Galp, and 1,4,6-linked α-d-Galp. PW-PS1 and PW-PS2 inhibited complement activation through both the classical and alternative pathways with CH₅₀ values of 0.28 and 0.13mg/mL, respectively, and AP₅₀ values of 0.40 and 0.35mg/mL, respectively. Preliminary mechanism studies using complement component-depleted sera showed that PW-PS1 acted on the C1q, C3, and C9 components and that PW-PS2 acted on the C1q, C2, C3, C5, and C9 components.

CONCLUSION

Our study suggested that PW-PS1 and PW-PS2 could be valuable for the treatment of diseases associated with the excessive activation of the complement system.

Purification and characterization of a novel polysaccharide-peptide complex from Clinacanthus nutans Lindau leaves

A novel polysaccharide-peptide complex CNP-1-2 with molecular weight of 9.17 × 10(4) Da was obtained from Clinacanthus nutans Lindau leaves by hot water extraction, ethanol precipitation, and purification with Superdex 200 and DEAE-Sepharose Fast Flow column chromatography. CNP-1-2 exhibited the highest growth inhibitory effect on human gastric cancer cells SGC-7901 with inhibition ratio of 92.34% and stimulated activation of macrophages with NO secretion level of 47.53 μmol/L among the polysaccharide fractions. CNP-1-2 comprised approximately 87.25% carbohydrate and 9.37% protein. Monosaccharide analysis suggested that CNP-1-2 was composed of L-rhamnose, l-arabinose, D-mannose, D-glucose and D-galactose with a molar ratio of 1.30:1.00:2.56:4.95:5.09. Methylation analysis, FT-IR, and (1)H NMR spectroscopy analysis revealed that CNP-1-2 might have a backbone consisting of 1,4-linked Glcp, 1,3-linked Glcp, 1,3-linked Manp, 1,4-linked Galp, 1,2,6-linked Galp and 1,2,6-linked Galp. Its side chain might be composed of 1-linked Araf, 1,6-linked Galp and 1-linked Rhap residues. AFM (atomic force micrograph) analysis revealed that CNP-1-2 had the molecular aggregation along with branched and entangled structure.

Structural characterization of two water-soluble polysaccharides from black soybean (Glycine max (L.) Merr.)

Black soybeans (Glycine max (L.) Merr.) have been widely used as a health food and medicinal herb in oriental medicine. In the present study, the chemical structures of two water-soluble polysaccharides (black soybean polysaccharide 1 (BSPS-1) and black soybean polysaccharide 3 (BSPS-3)) isolated from black soybeans were characterized by high performance size-exclusion chromatography (HPSEC), methylation analysis, and 1D (1H, 13C) and 2D (COSY, TOCSY, HSQC, NOESY, and HMBC) NMR spectra. The molecular weights of BSPS-1 and BSPS-3 were 1.95 × 105 and 1.88 × 105 Da, respectively. Methylation analysis and NMR spectra indicate that BSPS-1 is composed of 1,6-α-d-glucopyranosyl residues. By contrast, BSPS-3 is mainly composed of a 1,3-β-d-galactopyranosyl residue backbone with side chains substituted at the O-6 position consisting of large content of T-α-l-Araf-(1→ residues, and small contents of →5)-α-l-Araf-(1→, →2)-α-l-Rhap-(1→, and 4-O-Me-β-d-GlcAp-(1→ residues. Our results suggest that BSPS-1 is a linear (1→6)-α-d-glucan, whereas BSPS-3 is a type II arabinogalactan. The unique structures of BSPS-1 and BSPS-3 indicate that they might have wide applications in food and pharmaceutical industries.

Structural studies of arabinan-rich pectic polysaccharides from Abies sibirica L. Biological activity of pectins of A. sibirica

Highly branched arabinan-rich pectic polysaccharides, containing 84% of arabinose, was extracted from wood greenery of Abies sibirica L. The structure of arabinan was studied by the 1D and 2D NMR spectroscopy. The macromolecule backbone was represented mainly by RG-I (molar ratio GalA:Rha ∼ 1.3:1) patterns with high degree of rhamnose branching. Side chains were comprised of 1,5-linked α-L-Araf residues (the major part of polymer mass), 1,3,5-di-O- and 1,2,3,5-tri-O-linked α-L-Araf residues, confirming the presence of highly branched 1,5-α-L-arabinan. Although most L-Araf were in α-anomeric form, minor terminal β-L-Araf-(1 →... was detected. 1,4-β-D-linked Galp residues found in the side chains account for minor AG-I or 1,4-galactan, as compared to arabinan. A tentative structure was proposed. Polysaccharides obtained from Siberian fir greenery were screened for biological activity. Galacturonan had a strongest stimulating effect on germination and growth rate of seeds, germs and roots of Triticum aestivum, Avena sativa, and Secale cereale.