Structural characterization and anticomplement activity of an acidic polysaccharide from Hedyotis diffusa

Functional properties, structural characteristics, and anti-complementary activities of two degraded polysaccharides from strawberry fruits

Two low-molecular-weight polysaccharides (DPSP50 and DPSP70) were obtained using hydrogen peroxide-vitamin C (H2O2-Vc) treatment at 50 °C and 70 °C, respectively. Both DPSP50 and DPSP70 comprised the same six monosaccharides in different ratios, and their molecular weights (Mws) were 640 kDa and 346 kDa, respectively. Functional properties analyses demonstrated that DPSP50 and DPSP70 each had an excellent water holding capacity, oil absorption capacity, and emulsion properties, as well as shear-thinning characteristics and viscoelastic properties. Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic assays confirmed the existence of α-, β-pyranose rings and the same six sugar residues in DPSP50 and DPSP70. The results of Congo red test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) demonstrated that DPSP50 and DPSP70 did not contain triple-helix conformations, but were amorphous aggregates with flake-like shape and rough surface. Additionally, both DPSP50 and DPSP70 showed strong anti-complementary activities through the classical pathway and the alternative pathway. The results support the potential utility of these degraded polysaccharides from strawberry fruits in functional foods and medicines.

Flavonoid substituted polysaccharides from Tamarix chinensis Lour. alleviate H1N1-induced acute lung injury via inhibiting complement system

ETHNOPHARMACOLOGICAL RELEVANCE

Viral pneumonia is a highly pathogenic respiratory infectious disease associated with excessive activation of the complement system. Our previous studies found that the anticomplement polysaccharides from some medicinal plants could significantly alleviate H1N1-induced acute lung injury (H1N1-ALI). The leaves and twigs of Tamarix chinensis Lour. are traditionally used as a Chinese medicine Xiheliu for treating inflammatory disorders. Interestingly, its crude polysaccharides (MBAP90) showed potent anticomplement activity in vitro.

AIM OF THE STUDY

To evaluate the therapeutic effects and possible mechanism of MBAP90 on viral pneumonia and further isolate and characterize the key active substance of MBAP90.

MATERIALS AND METHODS

The protective effects of MBAP90 were evaluated by survival tests and pharmacodynamic experiments on H1N1-ALI mice. Histopathological changes, viral load, inflammatory markers, and complement deposition in lungs were analyzed by H&E staining, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC), respectively. An anticomplement homogenous polysaccharide (MBAP-3) was obtained from MBAP90 by bio-guided separation, and its structure was further characterized by methylation analysis and NMR spectroscopy.

RESULTS

Oral administration of MBAP90 at a dose of 400 mg/kg significantly increased the survival rate of mice infected with the lethal H1N1 virus. In H1N1-induced ALI, mice treated with MBAP90 (200 and 400 mg/kg) could decrease the lung index, lung pathological injury, the levels of excessive proinflammatory cytokines (IL-6, TNF-α, MCP-1, IL-18, and IL-1β), and complement levels (C3c and C5b-9). In addition, MBAP-3 was characterized as a novel homogenous polysaccharide with potent in vitro anticomplement activity (CH50: 0.126 ± 0.002 mg/mL), containing 10.51% uronic acids and 9.67% flavonoids, which were similar to the composition of MBAP90. The backbone of MBAP-3 consisted of →4)-α-D-Glcp-(1→, →3,4,6)-α-D-Glcp-(1→, and →3,4)-α-D-Glcp-(1→, with branches comprising α-L-Araf-(1→, α-D-GlcpA-(1→, →4,6)-α-D-Manp-(1→ and →4)-β-D-Galp-(1 → . Particularly, O-6 of →4)-β-D-Galp-(1→ was conjugated with a flavonoid, myricetin.

CONCLUSIONS

MBAP90 could ameliorate H1N1-ALI by inhibiting inflammation and over-activation of the complement system. These polysaccharides (MBAP90 and MBAP-3) with relative high contents of uronic acid and flavonoid substituent might be vital components of T. chinensis for treating viral pneumonia.

Exploring inhibitory components of Hedyotis diffusa on androgen receptor through molecular docking and molecular dynamics simulations

To explore the effective ingredients and mechanisms of action in Hedyotis diffusa (HD) that have inhibitory effects on androgen receptors (AR) using molecular docking and molecular dynamics simulations (MDS). The effective ingredients of HD were collected through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database and literatures. All components were docked with AR using Libdock. The receptor ligand interaction between the optimal ligand and AR were analyzed. Two simulation systems, namely I and II, containing AR and testosterone propionates (TP) were constructed, which System II contained the optimal ligand. The duration of the MDS was set to 300 ns. The distance between TP and AR peripheral active sites, root mean square deviation of ligand and receptor, receptor radius of gyration, distance between ligand center and binding site center, and ligand receptor binding energy were analyzed. 37 components of HD were collected, and the optimal ligand was MOL001656. MOL001656 forms hydrogen bonds with residues LEU48, PHE108, GLN55, LEU45, and ASN49 of AR. MDS have found that binding of TP to AR active sites can be observed in System I. The root mean square deviation of AR and MOL001656 both tended to stabilize in System II, with no significant fluctuations in the radius of gyration of AR and no significant fluctuations in the distance between ligand and binding cavity, indicating that the receptor ligand structure is relatively stable and their binding is relatively stable. The binding energy between AR and MOL001656 was -29.33 ± 3.84 kcal/mol. HD contains multiple effective ingredients that may have inhibitory AR activity. MOL001656 can occupy binding sites, thereby may exerting AR inhibitory effects.

Preparation of a new resource food-arabinogalactan and its protective effect against enterotoxicity in IEC-6 cells by inhibiting endoplasmic reticulum stress

Plant polysaccharides can be used as bioactive natural polymers that provide health benefits, however high molecular weight neutral polysaccharides have not shown good bioactivity. In this study, high molecular weight neutral arabinogalactan was isolated and structurally characterized to investigate it antioxidant activity against IEC-6 cells. In this study, a neutral polysaccharide (AG-40-I-II) was obtained from the roots of Larix gmelinii (Rupr.) Kuzen. and purified using ethanol fractional precipitation and purification on a DEAE-52 cellulose column and a Superose 12 gel filtration column. The structural characteristics of AG-40-I-II was detected by chemical and spectroscopic methods. The results showed that the average molecular weight of AG-40-I-II was 18.6 kDa, the main chain was composed of →4)-β-D-Gal-(1, → 4, 6)-β-D-Gal-(1 and →4)-β- D-Glc-(1, the side chain is composed of T-β-L-Araf(1 → 6). The effect of AG-40-I-II on H2O2-induced IEC-6 cell injury was determined by MTT method. Besides, AG-40-I-II could reduce the level of MDA and increase SOD activity on IEC-6 cells, which could significantly inhibit the production of ROS. Importantly, AG-40-I-II inhibited the splicing of XBP1 by IRE1α through the ERS pathway and reduced the cell apoptosis induced by H2O2. In summary, the results of this study indicate that AG-40-I-II, as a natural source of plant polysaccharides, has good antioxidant activity, and is expected to become a safe plant source of natural antioxidants, which has great potential in biomedicine potential.

Hedyotis diffusa-Sculellaria barbata (HD-SB) suppresses the progression of colorectal cancer cells via the hsa_circ_0039933/hsa-miR-204-5p/wnt11 axis

Our previous study confirmed that the combination of Hedyotis diffusa (HD) and Scutellaria barbata (SB) significantly inhibited colorectal cancer cell proliferation and the WNT signaling pathway. However, the exact molecular modulation remains unclear. In this study, colorectal cancer cells (SW620) were treated with 1 mg/mL HD-SB for 24 h, and high-throughput sequencing of circRNAs was performed. The level of hsa_circ_0039933 in three colorectal cancer cell lines (HT-29, SW620, and HCT116) was verified by qPCR. After transfection of hsa_circ_0039933 overexpression plasmids or small interfering RNAs, CCK8, apoptosis, cell migration, and cell invasion were utilized to evaluate the function of hsa_circ_0039933 in the progression of colorectal cancer cells. We identified hsa_circ_0039933, which was downregulated in HD-SB-induced colorectal cancer cells and positively related to colorectal cancer progression. In SW620 cells with relatively high expression of hsa_circ_0039933, interfering with the expression of hsa_circ_0039933 inhibited the proliferation, invasion, and migration of SW620 cells. In HCT116 cells with relatively low expression of hsa_circ_0039933, overexpression of hsa_circ_0039933 promoted the proliferation and invasion and migration ability of HCT116. Mechanistically, hsa_circ_0039933 targeted hsa-miR-204-5p to increase the expression of wnt11, leading to the activation of the Wnt pathway, thereby promoting the proliferation of colorectal cancer cells. This work revealed the potential molecular mechanism of HD-SB for the treatment of colorectal cancer, which was to inhibit the Wnt signaling pathway through the hsa_circ_0039933/hsa-miR-204-5p/wnt11 axis, then suppressing proliferation, migration, and invasion in the colorectal cancer cell.

Flavonoid-Rich Extract of Oldenlandia diffusa (Willd.) Roxb. Inhibits Gastric Cancer by Activation of Caspase-Dependent Mitochondrial Apoptosis

OBJECTIVE

To evaluate the apoptosis and cycle arrest effects of Oldenlandia diffusa flavonoids on human gastric cancer cells, determine the action mechanisms in association with the mitochondrial dependent signal transduction pathway that controls production of reactive oxygen species (ROS), and evaluate the pharmacodynamics of a mouse xenotransplantation model to provide a reference for the use of flavonoids in prevention and treatment of gastric cancer.

METHODS

Flavonoids were extracted by an enzymatic-ultrasonic assisted method and purified with D-101 resin. Bioactive components were characterized by high-performance liquid chromatography. Cell lines MKN-45, AGS, and GES-1 were treated with different concentrations of flavonoids (64, 96, 128, 160 µg/mL). The effect of flavonoids on cell viability was evaluated by MTT method, and cell nuclear morphology was observed by Hoechst staining. The apoptosis rate and cell cycle phases were measured by flow cytometry, the production of ROS was detected by laser confocal microscope, the mitochondrial membrane potential (MMP) were observed by fluorescence microscope, and the expression of apoptotic proteins related to activation of mitochondrial pathway were measured by immunoblotting. MKN-45 cells were transplanted into BALB/c nude mice to establish a xenograft tumor model. Hematoxylin and eosin staining was used to reveal the subcutaneous tumor tissue. The tumor volume and tumor weight were measured, the expression levels of proliferation markers proliferating cell nuclear antigen (PCNA) and Ki-67 were detected by immunohistochemistry, and the expression levels of CA72-4 were measured by enzyme linked immunosorbent assay.

RESULTS

Oldenlandia diffusa flavonoids inhibited proliferation of MKN-45 and AGS human gastric cancer cells, arrested the cell cycle in G₁/S phase, induced accumulation of ROS in the process of apoptosis, and altered MMP. In addition, flavonoids increased Apaf-1, Cleaved-Caspase-3, and Bax, and decreased Cyclin A, Cdk2, Bcl-2, Pro-Caspase-9, and Mitochondrial Cytochrome C (P<0.05). The MKN-45 cell mouse xenotransplantation model further clarified the growth inhibitory effect of flavonoids towards tumors. The expression levels of PCNA and Ki-67 decreased in each flavonoid dose group, the expression level of CA72-4 decreased (P<0.05).

CONCLUSION

Flavonoids derived from Oldenlandia diffusa can inhibit proliferation and induce apoptosis of human gastric cancer cells by activating the mitochondrial controlled signal transduction pathway.

Structural characterization and protective effect against renal fibrosis of polysaccharide from Ligustrum lucidum Ait

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Ligustri Lucidi (FLL), the fruit of Ligustrum lucidum Ait., is a traditional Chinese medicine that has been used for tonifying the kidney and liver for decades.

AIM OF THE STUDY

This study aimed to explore and identify polysaccharides from FLL and elucidate its protective effect against renal fibrosis.

MATERIALS AND METHODS

Polysaccharides were extracted and isolated from FLL. The purified fraction was identified by serial phytochemical work, such as gel-permeation chromatography, ion chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Mice with unilateral ureteral obstruction (UUO) were applied as a renal fibrosis model. The male UUO mice were pretreated with heteropolysaccharide (Poly) 1 week prior to surgery and continuously treated for 7 days after the operation. Renal fibrosis was assessed by Periodic Acid-Schiff (PAS) staining and Masson's trichrome staining in paraffin-embedded slides. The murine mesangial cells SV40-MES13 upon angiotensin II (Ang II) treatment were developed as an in vitro fibrotic model. The cells were treated by Poly in the presence of Ang II. Molecular expression was detected by RT-PCR, immunoblotting, and immunofluorescence staining.

RESULTS

We identified a heteropolysaccharide composed of arabinose and galactose (molar ratio, 0.73:0.27) with a predicted chemical structure characterized by a backbone composed of 1,5-α-Araf, 1,3,5-α-Araf, 1,6-α-Galp, and 1,3,6-β-Galp and side chains comprised of T-α-Araf, T-α-Arap, and 1,3-α-Araf. Pretreatment of UUO mice with Poly effectively alleviated glomerulosclerosis and tubulointerstitial fibrosis. Moreover, Poly pretreatment down-regulated the expression of extracellular matrix (ECM) protein fibronectin (FN), profibrotic factor VEGF, proinflammatory cytokines MCP-1 and Rantes in the obstructed kidney. Similarly, the incubation of SV40-MES13 cells with Poly significantly inhibited Ang II-induced elevation in accumulation and expression level of FN and attenuated Ang II-evoked up-regulation in protein expression of MCP-1 and Rantes.

CONCLUSIONS

Our study isolated and identified a naturally occurring heteropolysaccharide in FLL and revealed its potential in protecting the kidneys from fibrosis.

An anticomplement homogeneous polysaccharide from Hedyotis diffusa attenuates lipopolysaccharide-induced acute lung injury and inhibits neutrophil extracellular trap formation

BACKGROUND

Owing to the involvement of the overactivated complement system in acute lung injury (ALI) development, anticomplement components may attenuate ALI. Hedyotis diffusa is a traditional Chinese medicine for treating lung heat and its crude polysaccharides (HDP) exhibit significant anticomplement activity in vitro.

PURPOSE

To obtain an anticomplement homogeneous polysaccharide from HDP and verify its therapeutic effect and mechanism on ALI.

METHODS

Diethylaminoethyl-52 (DEAE-52) cellulose and gel permeation columns were used to isolate a homogeneous polysaccharide HD-PS-3, which was then characterized using nuclear magnetic resonance (NMR) and methylation analysis. In vitro, the anticomplement activities of HD-PS-3 through classical and alternative pathways were determined using a hemolytic test. The therapeutic effects of HDP and HD-PS-3 on ALI were evaluated in lipopolysaccharide (LPS) intratracheal instilled mice. Hematoxylin and eosin (H&E) staining, enzyme-linked immunosorbent assay (ELISA), and immunohistochemical staining were used to assess histological changes, measure cytokine levels, and evaluate the degree of complement component 3c (C3c) deposition and neutrophil infiltration, respectively. ELISA, western blotting, and immunofluorescence were used to analyze neutrophil extracellular trap (NET) formation.

RESULTS

From HDP, 1.5 g of the homogeneous polysaccharide HD-PS-3 was obtained. HD-PS-3 was an acidic heteropolysaccharide with an acetyl group, which was composed of →4,6)-α-Glcp-(1→, →3,4)-α-Glcp-(1→, →4)-α-Glcp-(1→, →4,6)-α-Galp-(1→, →5)-α-Araf-(1→, α-Rhap-(1→, α-Araf-(1→, α-GlcpA-(1→, →4)-β-Manp-(1→, β-Manp-(1→ and →3)-β-Manp-(1→. The in vitro results suggest that HD-PS-3 exhibited anticomplement activity with CH₅₀ and AP₅₀ values of 115 ± 12 μg/ml and 307 ± 11 μg/ml, respectively. After confirming the efficacy of HDP (200 mg/kg) in attenuating lung injury, the effect of HD-PS-3 on ALI was also investigated. HD-PS-3 (75 and 150 mg/kg) attenuated LPS-induced ALI as well, evidenced by lung pathology, lung injury scores, protein concentration, leukocyte counts, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) contents in bronchoalveolar lavage fluid (BALF). Mechanistically, HD-PS-3 inhibited complement activation, manifested in reduced pulmonary C3c deposition in lung tissue and complement component 3a (C3a) content in BALF. Neutrophil recruitment was also reduced by HD-PS-3, with significantly reduced pulmonary neutrophil infiltration and lower levels of C-X-C motif chemokine ligand 1 (CXCL1) and myeloperoxidase (MPO) in BALF. In addition, HD-PS-3 reduced the levels of MPO-DNA complex in BALF, decreased citrullinated histone H3 (Cit H3) expression and NET formation (colocalization of MPO, Cit H3, and DNA) in lung tissue.

CONCLUSION

An anticomplement homogeneous polysaccharide HD-PS-3 was isolated from H. diffusa. HD-PS-3 exhibited a therapeutic effect against ALI, and the mechanism might be related to its inhibitory effects on complement activation, neutrophil recruitment, and NET formation.

Acetylation Modification, Characterization, and Anticomplementary Activity of Polysaccharides from Rhododendron dauricum Leaves

This study focuses on the acetylation modification of polysaccharides from Rhododendron dauricum leaves (RDPs) with a high degree of substitution (DS) and then discusses their characterization and biological activity. The optimum acetylation conditions of RDPs were optimized by response surface methodology, which were reaction time 3 h, reaction temperature 50 °C, and the liquid-solid ratio 16 mL/g. Under the optima schemes, two eco-friendly acetylated polysaccharides from R. dauricum leaves (AcRDP-1 with DS of 0.439 ± 0.025 and AcRDP-2 with DS of 0.445 ± 0.022) were prepared. The results of structural characterization showed that the AcRDP-1 (9.3525 × 10³ kDa) and AcRDP-2 (4.7016 × 10³ kDa) were composed of mannose, glucose, galactose, and arabinose with molar ratios of 1.00:5.01:1.17:0.15 and 1.00:4.47:2.39:0.88, respectively. Compared with unmodified polysaccharides, the arabinose content and molecular weight of the two acetylated polysaccharides decreased, and their triple helix conformation disappeared, and further improved their anticomplementary activity. The two acetylated polysaccharides showed stronger a complement inhibition effect than the positive drug by blocking C2, C3, C4, C5, C9, and factor B targets in the classical and alternative pathways. This research indicated that acetylation modification could effectively enhance the anticomplementary activity of RDPs, which is beneficial for the development and utilization of R. dauricum leaves.

Isolation, characterization and anticomplementary activity of polysaccharides from the rhizomes of Belamcanda chinensis (L.) DC

The polysaccharides from the rhizomes of Belamcanda chinensis (L.) DC. (BCPs) were obtained by optimal water extraction (extraction temperature 84℃, liquid to solid ratio 42 mL/g and extraction time 100 min), the extraction yield of BCPs was 23.01 ± 0.27% (n=3). Furthermore, two novel polysaccharides (BCP-A1 and BCP-B1) were purified by column chromatography. The BCP-A1 (6.0820×104 kDa) was composed of β -D-Manp-(1→, β -D-Glcp-(1→, →4)-α-D-Galp-(1→ and →3,4)- β-D-Galp-(1→, and BCP-B1 (2.2744×104 kDa) was composed of →5)-α-L-Araf -(1→, β -D-Manp-(1→, β-D-Glcp-(1→, →4)-α-D-Glcp, →4)-α-D-Galp-(1→, →4)-α-D-Galp A-(1→ and →3,4)-β-D-Galp-(1→. In anticomplementary experiments, BCP-A1 (CH50: 0.009 ± 0.003 mg/mL; AP50: 0.015 ± 0.003 mg/mL) and BCP-B1 (CH50: 0.004 ± 0.001 mg/mL; AP50: 0.028 ± 0.005 mg/mL) exhibited potent anticomplementary activity, and acted on C2-, C4- and Factor B components. Our study provides a foundation for BCP-A1 and BCP-B1 as potential complement inhibitors to treat diseases involving with excessive activation of the complement system.

Two Natural Flavonoid Substituted Polysaccharides from Tamarix chinensis: Structural Characterization and Anticomplement Activities

Two novel natural flavonoid substituted polysaccharides (MBAP-1 and MBAP-2) were obtained from Tamarix chinensis Lour. and characterized by HPGPC, methylation, ultra-high-performance liquid chromatography-ion trap tandem mass spectrometry (UPLC-IT-MSⁿ), and NMR analysis. The results showed that MBAP-1 was a homogenous heteropolysaccharide with a backbone of 4)-β-d-Glcp-(1→ and →3,4,6)-β-d-Glcp-(1→. MBAP-2 was also a homogenous polysaccharide which possessed a backbone of →3)-α-d-Glcp-(1→, →4)-β-d-Glcp-(1→ and →3,4)-β-d-Glcp-2-OMe-(1→. Both the two polysaccharides were substituted by quercetin and exhibited anticomplement activities in vitro. However, MBAP-1 (CH₅₀: 0.075 ± 0.004 mg/mL) was more potent than MBAP-2 (CH₅₀: 0.249 ± 0.006 mg/mL) and its reduced product, MBAP-1R (CH₅₀: 0.207 ± 0.008 mg/mL), indicating that multiple monosaccharides and uronic acids might contribute to the anticomplement activity of the flavonoid substituted polysaccharides of T. chinensis. Furthermore, the antioxidant activity of MBAP-1 was also more potent than that of MBAP-2. In conclusion, these two flavonoid substituted polysaccharides from T. chinensis were found to be potential oxidant and complement inhibitors.

Physicochemical properties, immunostimulatory and antioxidant activities of a novel polysaccharide isolated from Mirabilis himalaica (Edgew) Heim

Herbal medicines often contain bioactive polysaccharides. However, many medicinal herbs have not been explored for any active saccharides that may play key roles in their bioactivities. Herein, we extracted a novel polysaccharide from Mirabilis himalaica (Edgew) heim (denoted MHHP), a popular medicinal ingredient in traditional medicines. The structural and morphological characteristics of MHHP were measured and elucidated by high-performance gel permeation chromatography, gas chromatography connected with mass spectrometry, Fourier transform infrared and nuclear magnetic resonance spectroscopy as well as scanning electron microscopy. MHHP was homogeneous with a molecular weight of 16.1 kDa, M _w/M _n = 1.33, containing mainly α-d-glucan residues with (1→4)-linkage. The biological activities of MHHP upon proliferation of splenic lymphocyte, activation of related cytokine and production of nitric oxide (NO) in RAW264.7 cells were investigated in vitro. MHHP induced proliferation of mouse spleen lymphocytes and significantly promoted the secretion in TNF-α, IL-6 and NO production in RAW264.7 cells. Meanwhile, MHHP exhibited relatively low antioxidant abilities. Our data suggested that MHHP may have potential immunoregulatory and anti-inflammatory activity, with a moderate antioxidant activity.

Isolation and Structural Characterization of Two Polysaccharides from Dracocephalum moldavica and Their Anti-Complementary Activity

The two novel polysaccharides, DMP-1 and DMP-2, with molecular weights of 4.1553×10⁵  kDa and 1.9764×10⁵  kDa, respectively, were isolated from Dracocephalum moldavica. The structural characterization indicated that DMP-1 and DMP-2 shared a similar backbone consisting of →5)-Araf-(1→, Manp-(1→, Glcp-(1→, →2)-Manp-(1→, →6)-Glcp-(1→ and →3,6)-Galp-(1→ with a different molar ratios and triple-helix structures with α- and β-type glycosidic bonds. The anti-complementary activity evaluation showed that DMP-1 and DMP-2 had strong complement inhibition through the classical pathway (CP), alternative pathway (AP) and lectin pathway (LP). Mechanistic studies indicated that DMP-1 can block the activation cascade of the complement system by targeting C2, C3, C5, C9, Factor B and Factor P, and that DMP-2 inhibited complement activation by blocking C2, C3, C4, C5, C9 and Factor B.

Hypoglycaemic and anti-ageing activities of green alga Ulva lactuca polysaccharide via gut microbiota in ageing-associated diabetic mice

Ageing-related type 2 diabetes is a significant public health problem. Particularly, the number of cases and fatality rates of ageing-associated diabetes increase with population ageing. This study aimed to investigate the structural characterisation of Ulva lactuca polysaccharide (ULP) and the hypoglycaemic effect on ageing-associated diabetic mice using gut microbiota variation. Sugar residuals analysis showed that the purified ULP (ULP-1) comprised β-D-Xylp-(1→3)-β-D-Arap-(1→6)-β-D-Galp-(1→6)-β-D-Glcp linked to [→α-L-Rhap-(1→4)-β-D-GlcpA→]_n and α-D-Manp-(1→4)-α-L-Rhap(2SO₃^-)-(1→2)-α-L-Rhap(4SO₃^-)-(1→2)-α-L-Arap-(1→2)-α-L-Rhap-(1→ as its side chains at β-D-Glcp. Moreover, ULP modulated the expression levels of p16^Ink4a, MMP2, FoxO1, GLP-1/GLP-1R, STAT3, and GLUT4 to improve the status of ageing and diabetes, which was concurrent with the increased abundance of Dubosiella, Enterococcus, Romboutsia, Bifidobacterium, Kurthia, Clostridium_sensu_stricto_1, Corynebacterium, Faecalibaculum, Aerococcus and Vibrio. Notably, Dubosiella, Romboutsia, Bifidobacterium, Turicibacter and Clostridium_sensu_stricto_1 could serve as important intermediates for delaying ageing and diabetes. Additionally, the ULP-1 structure is strongly binding interaction with the target protein through hydrogen bonding and Van der Waals force, especially for GLP-1 (-10.34 kcal/mol), p16^Ink4a (-10.51 kcal/mol) and GLP-1R (-8.57 kcal/mol). Moreover, the average length of the hydrogen bond was observed to be 2.36 MPa, which is smaller than that of the traditional hydrogen bond. Therefore, ULP has the potential to function as a nutraceutical to delay or prevent the development of ageing-related type 2 diabetes.

Structural characterization, antioxidant, and anti-inflammatory activity of polysaccharides from Plumula Nelumbinis

A polysaccharide from Plumula Nelumbinis (PNP), was isolated and purified. PNP had a molecular weight of 450 kDa and consisted five monosaccharides, including rhamnose, galacturonic acid, xylose, galactose, and arabinose. The methylation and nuclear magnetic resonance (NMR) analysis revealed that the main glycosidic linkage types of PNP were →5)-α-L-Araf-(1→, →3)-β-D-Galp-(1→, β-D-Xylp-(→1, →3,4)-β-D-Rhap-(1→, →4)-β-D-GalpA-(1→. In the range of 25-1200 μg/mL, PNP had no cytotoxicity to RAW264.7 cells. PNP could protect RAW264.7 cell from oxidative damage by reducing the production of ROS and MDA and the secretion of LDH, enhancing the activity of SOD, CAT, and GSH-Px, and increasing the content of GSH. Anti-inflammatory activity experiments showed that PNP inhibited the expression of NO, TNF-α, INF-γ, IL-1β, and IL-6. PNP could inhibit the activation of MAPK/NF-κB cell pathways. PNP could be used as a potential natural antioxidant and anti-inflammatory substance in functional foods and pharmaceuticals.

Relationship Between the Structure and Immune Activity of Components From the Active Polysaccharides APS-II of Astragali Radix by Enzymolysis of Endo α-1,4-Glucanase

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.

Characterization of Alpinia officinarum Hance polysaccharide and its immune modulatory activity in mice

This study aimed to verify the regulating effect of a novel water-soluble polysaccharide (AOHP) extracted from Alpinia officinarum Hance on mouse immunity and to characterize its structure feature. The cellulose...

The structural characterization and anticancer activity of a polysaccharide from Coriolus versicolor

Coriolus versicolor is a traditional Chinese medicine and is widely applied as a functional food. In this study, a homogeneous polysaccharide, YZP-1a, was isolated from C. versicolor and its structure and anticancer activity were investigated.

Polysaccharide extracted from Althaea officinalis L. root: New studies of structural, rheological and antioxidant properties

A water-soluble acidic polysaccharide (AOP-2) from Althaea officinalis L. root was isolated by water extraction and purified by ion exchange chromatography (Cellulose DEAE-52) and gel filtration (Sephadex G-200). The structure characteristics of AOP-2 was determined by gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) spectrum and gas chromatography-mass spectrometry (GC_MS). The results indicated that the AOP-2 was an acidic hetropolysaccharide with the molecular weight of 639.27 kDa. The AOP-2 composed of 51% galacturonic acid, 32.56% rhamnose, 12.73% glucose and 3.71% galactose. It could be found that the main backbone chain of AOP-2 consisted of →3)-α-D-GalpA-(1→, →3)-α-D-Rhap-(1→ and→3,4)-β-D-Galp-(1→ with branches of →4)-α-D-Rhap-(1→, →4)-α-D-Glcp-(1→ and α-D-Rhap-(1 → . Thermal analysis revealed that the AOP-2 had high thermal stability and according to the results obtained from XRD analysis, it had a semi-crystalline structure. The results of Steady-shear flow and dynamical viscoelasticity showed that AOP-2 solutions exhibited shear-thinning behavior with high viscosity and a weak gel-like behavior at concentrations above 1% in linear viscoelastic region. In addition, it showed relatively high antioxidant property.

Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

Isolation, purification, structural characteristics, pharmacological activities, and combined action of Hedyotis diffusa polysaccharides: A review

Hedyotis diffusa polysaccharides, as the main component and an important bioactive substance of Hedyotis diffusa, are effective immunomodulators with various pharmacological activities, including antitumour, anti-inflammatory, antioxidant, anti-fatigue and immunity-enhancing activities. The total polysaccharides extracted from Hedyotis diffusa and Scutellaria barbata have great effects in treating liver cancer, gastric cancer, rectal cancer, glioma and nasopharyngeal carcinoma. Moreover, different materials and extraction methods result in differences in the structure and bioactivity of Hedyotis diffusa polysaccharides. Therefore, this paper summarizes the isolation, purification, structural characteristics, pharmacological activities, and combined action of Hedyotis diffusa polysaccharides to provide a reference for further study.

Structural characteristics and anti-complement activities of polysaccharides from Sargassum hemiphyllum

Three polysaccharides (SH-1, SH-2 and SH-3) were purified from a brown macroalgea, Sargassum hemiphyllum. The autohydrolysis products from each polysaccharide were separated to three fractions (S fractions as oligomers, L fractions as low molecular weight polysaccharides and H fractions as high molecular weight polysaccharides). Mass spectroscopy of S fractions (SH-1-S, SH-2-S and SH-3-S) showed that these three polymers all contained short stretches of sulfated fucose. The structures of L fractions (SH-1-L, SH-2-L and SH-3-L) were determined by nuclear magnetic resonance (NMR). SH-1-L was composed of two units, unit A (sulfated galactofucan) and unit B (sulfated xylo-glucuronomannan). Unit A contained a backbone of (1, 6-linked β-D-Gal) n1, (1, 3-linked 4-sulfated α-L-Fuc) n2, (1, 3-linked 2, 4-di-sulfated α-L-Fuc) n3, (1, 4-linked α-L-Fuc) n4 and (1, 3-linked β-D-Gal) n5, accompanied by some branches, such as sulfated fuco-oligomers, sulfated galacto-oligomers or sulfated galacto-fuco-oligomers. And unit B consisted of alternating 1, 4-linked β-D-glucuronic acid (GlcA) and 1, 2-linked α-D-mannose (Man) with the Man residues randomly sulfated at C6 or branched with xylose (Xyl) at C3. Both SH-2-L and SH-3-L were composed of unit A and their difference was attributed to the ratio of n1: n2: n3: n4: n5. Based on monosaccharide analysis, we hypothesize that both SH-1-H and SH-2-H contained unit A and unit B while SH-3-H had a structure similar to SH-3-L. An assessment of anti-complement activities showed that the sulfated galactofucan had higher activities than sulfated galacto-fuco-xylo-glucuronomannan. These results suggest that the sulfated galactofucans might be a good candidate for anti-complement drugs.