A homogalacturonan from the radix of Platycodon grandiflorum and the anti-angiogenesis activity of poly-/oligogalacturonic acids derived therefrom

Preparation methods, structural characteristics, and biological activity of polysaccharides from Platycodon grandiflorus

Platycodon grandiflorus (P. grandiflorus), a traditional Chinese medicinal herb used for both medicine and food, has a long history of treating respiratory infections, bronchitis, pneumonia, and other lung-related diseases. The therapeutic effects of P. grandiflorus are attributed to its chemical components, including polysaccharides. Among these components, Platycodon grandiflorus polysaccharides (PGP) are recognized as one of the most important and abundant active ingredients, exhibiting various biological activities such as prebiotic, antioxidant, antiviral, anticancer, antiangiogenic, and immune regulatory properties. Incorporating the principles of traditional Chinese medicine, carrier concepts, and modern targeted drug delivery technologies, PGP can influence the target sites and therapeutic effects of other drugs while also serving as a drug carrier for targeted and precise treatments. Therefore, it is essential to provide a comprehensive review of the extraction, separation, purification, physicochemical properties, and biological activities of PGP. In the future, by integrating new concepts, technologies, and processes, further references and guidance can be provided for the comprehensive development of PGP. This will contribute to the advancement of P. grandiflorus in various fields such as pharmaceuticals, health products, and food.

Recent advances in Platycodon grandiflorum polysaccharides: Preparation techniques, structural features, and bioactivities

Platycodon grandiflorum, a globally recognized medicinal and edible plant, possesses significant nutritional value and pharmacological value. In traditional Chinese medicine, it has the effects of tonifying the spleen and replenishing the Qi, moistening the lung and relieving the cough, clearing the heat and detoxifying, and relieving the pain. Accumulating evidence has revealed that the polysaccharides from P. grandiflorum (PGPs) are one of the major and representative biologically active macromolecules and have diverse biological activities, such as immunomodulatory activity, anti-inflammatory activity, anti-tumor activity, regulation of the gut microbiota, anti-oxidant activity, anti-apoptosis activity, anti-angiogenesis activity, hypoglycemic activity, anti-microbial activity, and so on. Although the polysaccharides extracted from P. grandiflorum have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge of their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. The main purpose of the present review is to provide comprehensively and systematically reorganized information on extraction and purification, structure characterizations, and biological functions as well as toxicities of PGPs to support their therapeutic potentials and sanitarian functions. New valuable insights for future research regarding PGPs were also proposed in the fields of therapeutic agents and functional foods.

The traditional use, structure, and immunostimulatory activity of bioactive polysaccharides from traditional Chinese root medicines: A review

As research on traditional Chinese medicine (TCM) has expanded, our understanding of the role it can have in controlling the immune system has increased. Polysaccharides from medicinal plants exhibit numerous beneficial therapeutic properties, presumably owing to their modulation of innate immunity and macrophage function. Numerous studies have demonstrated the multiple ways whereby certain polysaccharides can affect the immune system. In addition to stimulating immune cells, such as T cells, B lymphocytes, macrophages, and natural killer cells, polysaccharides stimulate complements and increase cytokine secretion. The biological functions of polysaccharides are directly correlated with their structures. This paper summarizes the sources, TCM uses, extraction and purification methods, structural characterization, in vitro and in vivo immune activities, and underlying molecular mechanisms of TCM root polysaccharides. Moreover, the structure-activity relationships of TCM root polysaccharides are emphasized and discussed. This review can provide a scientific basis for the research and industrial utilization of TCM root polysaccharides.

A homogalacturonan from Lonicera japonica Thunb. disrupts angiogenesis via epidermal growth factor receptor and Delta-like 4 associated signaling

A homogeneous polysaccharide named as LJW2F2 was extracted and purified from the flowers of Lonicera japonica Thunb. Structural characteristic indicated that LJW2F2 was a homogalacturonan composed of α-1,4-D-galacturonic acid with a molecular weight of 7.2 kDa. Previous investigation suggested that homogalacturonan might impede angiogenesis, however the mechanism is still vague. Here we reported that LJW2F2 significantly disrupted capillary-like tube formation of human microvascular endothelia cells (HMEC-1) on matrigel as well as the cells migration. Mechanism study revealed that LJW2F2 might inactivate phosphorylation of epidermal growth factor receptor (EGFR), subsequently suppress Raf, mitogen-activated protein kinase (MEK) and extracellular-related kinase (ERK) phosphorylation. Moreover, LJW2F2 markedly decreased the expression of Notch1 and Delta-like ligand 4 (Dll4). Therefore, our results suggested that LJW2F2 might be a potential angiogenesis inhibitor via disturbing multiple signaling pathways.

Structure, selenization modification, and antitumor activity of a glucomannan from Platycodon grandiflorum

Platycodon grandiflorum is consumed popularly as a nutritional and healthy plant in East Asia, which has multiple medicinal functions. As an exploration to elucidate the beneficial ingredients, an acetylated glucomannan (PGP40-1) was purified from P. grandiflorum. Structural analysis showed that PGP40-1 was composed of →4)-β-Manp-(1→, →4)-β-Glcp-(1→, →6)-β-Glcp-(1→, and terminal α-Glcp-(1→. PGP40-1 was found to possess weak antitumor activity in vitro, which was thus modified to afford a selenized polysaccharide (Se-PGP40-1) by the HNO₃/Na₂SeO₃ method. Se-PGP40-1 showed significant antitumor activity in cell and zebrafish models, which could inhibit tumor proliferation and migration by inducing cell apoptosis and blocking angiogenesis. The research not only clarifies the ingredients of P. grandiflorum with high economical value, but also affords a potential antitumor agent originating from the plant polysaccharide.

Structural characterization and evaluation the elicitors activity of polysaccharides from Chrysanthemum indicum

This research evaluates the elicitors activity and structure characterization of four Chrysanthemum indicum polysaccharides (CIPs) which were isolated from C. indicum, obtained CIP1, CIP2, CIP3, CIP4. Results demonstrated that there was a distinct difference in inducibility and CIP3 was significantly stronger than other CIPs through bioactivity-tests. Taking CIP3 with total carbohydrate content 91.93 % as a representative, its structure was elucidated as a relative molecular weight of 8. 741 × 10³ g/mol and mainly composed of xylose, galacturonic acid, galactose and glucuronic acid. Through GC, IR and NMR, CIP3 was determined to possess a backbone comprised of T-α-d-GalpA, 1,4-α-d-GlcpA, 1,2-α-d-Xylp, 1,3-α-l-Rhap, 1,2,4-α-l-Rhap and sidechains comprised of 1,3-β-d-Galp, 1,6-α-d-Galp, T-α-Glcp, 1,3-β-d-Glcp, 1,4-α-d-Glcp, 1,3,4-α-d-Manp, T-α-l-Fucp. Further results indicated that CIP3 with active sidechains could significantly increase the expression of defense genes in Atractylodes macrocephala Koidz (AM). It is believed that the sidechains of CIP3 were necessary to its elicitor activity via bioactivity tests.

Characterization of an antioxidant pectic polysaccharide from Platycodon grandiflorus

Platycodonis Radix is widely used as homology of medicine and food in China; polysaccharides are thought to be one of its functional constituents. In this study, a pectic polysaccharide, PGP-I-I, was obtained from the root of the traditional medicine plant Platycodon grandiflorus through ion exchange chromatography and gel filtration. This was characterized being mainly composed of 1,5-α-L-arabinan and both arabinogalactan type I (AG-I) and II chains linked to rhamnogalacturonan I (RG-I) backbone linked to longer galacturonan chains. In vitro bioactivity study showed that PGP-I-I could restore the intestinal cellular antioxidant defense under the condition of hydrogen peroxide (H₂O₂) treatment through promoting the expressions of cellular antioxidant genes and protect against oxidative damages.

Chemical characteristic and bioactivity of hemicellulose-based polysaccharides isolated from Salvia miltiorrhiza

Salvia miltiorrhiza roots (SMRs), the main component of cell wall from the residual waste extraction, differ depending on the forming ways of monosaccharides. The extraction from 8% sodium hydroxide solution (H-8) was characterized by gel permeation chromatography (GPC), monosaccharide composition, Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy. The structure model of hemicellulose-based polysaccharides (HBPs) was derived by combining one-dimensional and two-dimensional NMR. Monosaccharides difference and correlation were performed by partial least square analysis (PLS). Seven H-8s exhibited optimal inhibitory activities, which varied based on different sources of Danshen. The backbone structure indicated that 4-β-D-Xylp served as the main chain connected by 3-α-L-Araf or 5-α-L-Araf-1, 4-β-D-Galp, and β-D-Glcp branch, as well as α-L-Rhap, α-D-GalpA and α-D-GlcpA fragments. The variation of HBPs in terms of the structure and bioactivity of SMRs correlated with different cultivation sites can be a new approach to optimize and utilize the medical materials by chemical and biological aspects of natural macromolecules.

Suppression of High-Fat Diet-Induced Obesity by Platycodon Grandiflorus in Mice Is Linked to Changes in the Gut Microbiota

BACKGROUND

The root of Platycodon grandiflorus (PG) has a long-standing tradition in the Asian diet and herbal medicine, because of its anti-inflammatory and antiobesity effects. Changes in the gut microbiota can have dietary effects on host health, which suggests a relation between the 2.

OBJECTIVES

The aim of our study was to investigate the relation between PG-mediated suppression of obesity and the composition and functioning of the gut microbiota.

METHODS

Six-week-old male C57BL/6J mice were fed either a control diet (CON, 10% kcal from fat), a high-fat diet (HFD, 60% kcal from fat), or a PG-supplemented HFD for 18 wk. PG was administered by oral gavage at 2 g · kg body weight-1 · d-1. Body weight and food intake were monitored. Lipid metabolism, inflammation, and intestinal barrier function were determined. Amplicon sequencing of the bacterial 16S ribosomal RNA gene was used to explore gut microbiota structure, and nontargeted metabolomics analysis was performed to investigate metabolite concentrations in fecal samples.

RESULTS

We found that PG significantly ameliorated HFD-induced inflammation, recovered intestinal barrier integrity (reduced permeability by 39% , P = 0.008), reduced fat accumulation by 26% (P = 0.009), and changed the expression of key genes involved in the development of white adipose tissue (P < 0.05) in HFD-fed mice to similar levels in CON mice. Moreover, PG attenuated HFD-induced changes in the gut microbiota; it especially increased Allobaculum (7.3-fold, P = 0.002) relative to HFD, whereas CON was 15.2-fold of HFD (P = 0.002). These changes by PG were associated with an increase in the production of SCFAs (butyrate and propionate, P < 0.001) and other carbohydrate-related metabolites known to have a major role in disease suppression.

CONCLUSIONS

Our study demonstrated that PG beneficially changed the gut microbiota and the gut metabolome in HFD-fed mice, and suggests that the antiobesity effects of PG may be mediated via changes in gut microbiota composition and metabolic activity.

Biochemical Prospects of Various Microbial Pectinase and Pectin: An Approachable Concept in Pharmaceutical Bioprocessing

Both pectin and pectinase are vitally imperative biomolecules in the biotechnological sector. These molecules are a feasible non-toxic contrivance of nature with extensive applicative perception. Understanding pectic substances and their structure, unique depolymerization, and biochemical properties such as a catalytic mechanism and the strong interrelationship among these molecules could immensely enhance their applicability in industries. For instance, gaining knowledge with respect to the versatile molecular heterogeneity of the compounds could be considered as the center of concern to resolve the industrial issues from multiple aspects. In the present review, an effort has been made to orchestrate the fundamental information related to structure, depolymerization characteristics, and classification of pectin as well as the types and biochemical properties of pectinase. Furthermore, various production methods related to the optimization of the product and its significant contribution to the pharmaceutical industry (either pectinase or derived pectic substances) are described in this article.

PRP1, a heteropolysaccharide from Platycodonis Radix, induced apoptosis of HepG2 cells via regulating miR-21-mediated PI3K/AKT pathway

Two polysaccharides (PRP1 and PRP2) were isolated from Platycodonis Radix. Preliminary structural analysis indicated that PRP1 was composed of glucose, fructose, and arabinose in a molar ratio of 1:1.91:1.59 with a molecular weight of 440 kDa, whereas PRP2 was composed of arabinose, fructose, and galactose in a molar ratio of 1:1.39:1.18 with a molecular weight of 2.85 kDa. Compared with PRP2, PRP1 exerted stronger anticancer activity in vitro. Treatment with 5-30 μg/ml of PRP1 significantly inhibited the proliferation of HepG2 cells in vitro, and oral administration at the doses of 75-300 mg/kg also reduced the tumor growth in vivo. The miRNA expression patterns of human liver cancer cells HepG2 in vivo under PRP1 treatment were established, and microRNA-21 (miR-21) as the onco-miRNA was appreciably downregulated. PRP1 repressed the expression of miR-21, which directly targeted and suppressed PTEN (a negative regulator of the PI3K/Akt signaling cascade), and subsequently upregulated the expression of PTEN but downregulated the PI3K/AKT pathway, thereby promoting liver cancer cell apoptosis. These findings indicated that PRP1 inhibited the proliferation and induced the apoptosis of HepG2 mainly via inactivating the miR-21/PI3K/AKT pathway. Therefore, PRP1 could be used as a food supplement and candidate for the treatment of liver cancer.

Structural and rheological properties of pectic polysaccharide extracted from Ulmus davidiana esterified by succinic acid

The present study was carried out to investigate the physicochemical and structural properties of pectic polysaccharide extracted from Ulmus davidiana (UDP) and to determine the physicochemical, structural, and rheological properties of esterified UDP with succinic acid (ES-UDP). The results indicated that UDP had high amounts of galacturonic acids and various neutral sugars, such as galactose, rhamnose, and glucose. UDP was identified as a low methoxyl pectin, consisting of 1,4-linked α-d-GalpA (the main backbone chain), supported by the results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, and 1D Nuclear magnetic resonance (NMR) spectroscopy. In the FT-IR and XRD, no difference was detected between UPD and ES-UDPs. However, ¹H and ¹³C NMR spectra revealed that the new ester bonds were formed between a hydroxyl group of UDP and a carboxyl group of succinic acid during esterification. In the steady shear rheological analysis, the consistency index (K) of ES-UDP was significantly higher than that of UDP and increased significantly with increasing concentration of succinic acid. In the dynamic rheological analysis, the tan δ values of all ES-UDP solutions were significantly lower than those of the UDP solution.

Structural characterization of a novel acidic polysaccharide from Rosa roxburghii Tratt fruit and its α-glucosidase inhibitory activity

An acidic polysaccharide (RTFP-3) extracted from Rosa roxburghii Tratt fruit can inhibit the activity of α-glucosidase.

Structural elucidation of a polysaccharide from Chrysanthemum morifolium flowers with anti-angiogenic activity

The flowers of Chrysanthemum morifolium were extracted with 5% sodium hydroxide, yielding a neutral polysaccharide (JHB0S2) with a molecular weight of 16 kDa by anion-exchange chromatography on a DEAE-cellulose column and gel permeation chromatography on a Sephacryl S-200 HR column. JHB0S2 was found to contain glucose, xylose, arabinose and galactose in molar ratio of 2.9:2.3:1.0:1.2. Through the linkage analysis, partial acid hydrolysis and NMR spectra and so forth, indicated that its backbone consisted of 1,4-linked β-Glcp, nearly 50% of which was substituted at O-6 by 1,2-linked α-Xylp terminated with Galp or Xylp. Furthermore, some of 1,2-linked α-Xylp was substituted at O-4 by α-Araf-(1→5)-α-Araf-(1→6)-β-Galp. The biological test showed that JHB0S2 could inhibit the tube formation of HMEC-1 cells.

Characterization of two homogalacturonan pectins with immunomodulatory activity from green tea

Two natural homogalacturonan (HG) pectins (MW ca. 20 kDa) were isolated from green tea based on their immunomodulatory activity. The crude tea polysaccharides (TPS1 and TPS2) were obtained from green tea leaves by hot water extraction and followed by 40% and 70% ethanol precipitation, respectively. Two homogenous water soluble polysaccharides (TPS1-2a and TPS1-2b) were obtained from TPS1 after purification with gel permeation, which gave a higher phagocytic effect than TPS2. A combination of composition, methylation and configuration analyses, as well as NMR (nuclear magnetic resonance) spectroscopy revealed that TPS1-2a and TPS1-2b were homogalacturonan (HG) pectins consisting of a backbone of 1,4-linked α-D-galacturonic acid (GalA) residues with 28.4% and 26.1% of carboxyl groups as methyl ester, respectively. The immunological assay results demonstrated that TPS1-2, which consisted mainly of HG pectins, showed phagocytosis-enhancing activity in HL-60 cells.

Structural characterization and immunomodulatory effect of a polysaccharide HCP-2 from Houttuynia cordata

Immunomodulation of natural polysaccharides has been the hot topic of research in recent years. In order to explore the immunomodulatory effect of Houttuynia cordata Thunb., the water extract was studied and a polysaccharide HCP-2 with molecular weight of 60,000 Da was isolated by chromatography using DEAE Sepharose CL-6B and Sephacryl S-500 [corrected] HR columns. The structure characterization of HCP-2 was performed by Fourier transform infrared spectroscopy (FTIR), acidic hydrolysis, PMP derivation, HPLC analysis and nuclear magnetic resonance spectra (NMR). HCP-2 was elucidated as a pectic polysaccharide with a linear chain of 1,4-linked α-D-galacturonic acid residues in which part of the 6-carboxyl groups were methyl esterified and part of 2-hydroxyl groups were acetylated. The bioactivity assays showed that HCP-2 could increase the secretions of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), macrophage inhibitory protein-1α (MIP-1α), macrophage inhibitory protein-1β (MIP-1β), and RANTES (regulated on activation, normal T cell expressed and secreted) in human peripheral blood mononuclear cells (PBMCs), which play critical roles in the innate immune system and shape the adaptive immunity. Our results implied that HCP-2 could be an immune enhancer.

Homogalacturonans from preinfused green tea: structural characterization and anticomplementary activity of their sulfated derivatives

Two homogeneous water-soluble polysaccharides (TPSR4-2B and TPSR4-2C) were obtained from preinfused green tea. Their average molecular weights were estimated to be 41 kDa and 28 kDa, respectively. A combination of composition, methylation, and configuration analysis, as well as NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1-4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and 28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester. Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid-pyridine ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C demonstrated a stronger inhibitory effect on the complement activation through the classic pathway, compared to that of heparin. Preliminary mechanism studies by using complement component depleted-sera indicated that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r, C1s, C2, C5, and C9 but not with C3 and C4. The relationship between DS and the anticomplementary activity of sulfated derivatives of homogalacturonans showed that low sulfated derivatives of homogalacturonans also exhibited potent anticomplementary effect, which might greatly reduce the side effects related to heparin and oversulfated chondroitin sulfate, such as anticoagulant activity and allergic-type reaction. These results suggested that sulfated derivatives of homogalacturonans might be promising drug candidates for therapeutic complement inhibition.