Characterization of a novel polysaccharide from tetraploid Gynostemma pentaphyllum makino

Insights into the molecular mechanisms, structure-activity relationships and application prospects of polysaccharides by regulating Nrf2-mediated antioxidant response

The occurrence and development of many diseases are closely related to oxidative stress. In this context, accumulating evidence suggests that Nrf2, as the master switch of cellular antioxidant signaling, plays a central role in controlling the expression of antioxidant genes. The core molecular mechanism of polysaccharides treatment of oxidative stress-induced diseases is to activate Keap1/Nrf2/ARE signaling pathway, promote nuclear translocation of Nrf2, and up-regulate the expression of antioxidant enzymes. However, recent studies have shown that other signaling pathways in which polysaccharides exert antioxidant effects, such as PI3K/Akt/GSK3β, JNK/Nrf2 and NF-κB, have complex crosstalk with Keap1/Nrf2/ARE, may have direct effects on the nuclear translocation of Nrf2. This suggests a new strategy for designing polysaccharides as modulators of Nrf2-dependent pathways to target the antioxidant response. Therefore, in this work, we investigate the crosstalk between Keap1/Nrf2/ARE and other antioxidant signaling pathways of polysaccharides by regulating Nrf2-mediated antioxidant response. For the first time, the structural-activity relationship of polysaccharides, including molecular weight, monosaccharide composition, and glycosidic linkage, is systematically elucidated using principal component analysis and cluster analysis. This review also summarizes the application of antioxidant polysaccharides in food, animal production, cosmetics and biomaterials. The paper has significant reference value for screening antioxidant polysaccharides targeting Nrf2.

Single-cell transcriptome profiling reveals the spatiotemporal distribution of triterpenoid saponin biosynthesis and transposable element activity in Gynostemma pentaphyllum shoot apexes and leaves

Gynostemma pentaphyllum (Thunb.) Makino is an important producer of dammarene-type triterpenoid saponins. These saponins (gypenosides) exhibit diverse pharmacological benefits such as anticancer, antidiabetic, and immunomodulatory effects, and have major potential in the pharmaceutical and health care industries. Here, we employed single-cell RNA sequencing (scRNA-seq) to profile the transcriptomes of more than 50,000 cells derived from G. pentaphyllum shoot apexes and leaves. Following cell clustering and annotation, we identified five major cell types in shoot apexes and four in leaves. Each cell type displayed substantial transcriptomic heterogeneity both within and between tissues. Examining gene expression patterns across various cell types revealed that gypenoside biosynthesis predominantly occurred in mesophyll cells, with heightened activity observed in shoot apexes compared to leaves. Furthermore, we explored the impact of transposable elements (TEs) on G. pentaphyllum transcriptomic landscapes. Our findings the highlighted the unbalanced expression of certain TE families across different cell types in shoot apexes and leaves, marking the first investigation of TE expression at the single-cell level in plants. Additionally, we observed dynamic expression of genes involved in gypenoside biosynthesis and specific TE families during epidermal and vascular cell development. The involvement of TE expression in regulating cell differentiation and gypenoside biosynthesis warrant further exploration. Overall, this study not only provides new insights into the spatiotemporal organization of gypenoside biosynthesis and TE activity in G. pentaphyllum shoot apexes and leaves but also offers valuable cellular and genetic resources for a deeper understanding of developmental and physiological processes at single-cell resolution in this species.

Chinese medicine in the treatment of non-alcoholic fatty liver disease based on network pharmacology: a review

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by abnormalities in hepatic fat deposition, the incidence of which has been increasing year by year in recent years. It has become the largest chronic liver disease globally and one of the important causes of cirrhosis and even primary liver cancer formation. The pathogenesis of NAFLD has not yet been fully clarified. Modern medicine lacks targeted clinical treatment protocols for NAFLD, and most drugs lack efficacy and have high side effects. In contrast, Traditional Chinese Medicine (TCM) has significant advantages in the treatment and prevention of NAFLD, which have been widely recognized by scholars around the world. In recent years, through the establishment of a "medicine-disease-target-pathway" network relationship, network pharmacology can explore the molecular basis of the role of medicines in disease prevention and treatment from various perspectives, predicting the pharmacological mechanism of the corresponding medicines. This approach is compatible with the holistic view and treatment based on pattern differentiation of TCM and has been widely used in TCM research. In this paper, by searching relevant databases such as PubMed, Web of Science, and Embase, we reviewed and analyzed the relevant signaling pathways and specific mechanisms of action of single Chinese medicine, Chinese medicine combinations, and Chinese patent medicine for the treatment of NAFLD in recent years. These related studies fully demonstrated the therapeutic characteristics of TCM with multi-components, multi-targets, and multi-pathways, which provided strong support for the exact efficacy of TCM exerted in the clinic. In conclusion, we believe that network pharmacology is more in line with the TCM mindset of treating diseases, but with some limitations. In the future, we should eliminate the potential risks of false positives and false negatives, clarify the interconnectivity between components, targets, and diseases, and conduct deeper clinical or experimental studies.

Carboxymethylated Rhizoma alismatis Polysaccharides Regulate Calcium Oxalate Crystals Growth and Reduce the Regulated Crystals' Cytotoxicity

OBJECTIVE

This study explored the effects of polysaccharides (RAPD) extracted from the traditional anti-stone Chinese medicine Rhizoma alismatis and their carboxymethylated derivatives (RAPs) on the crystal phase, morphology, and size of calcium oxalate (CaOx). It also determined the damaging ability of the regulated crystals on human renal tubular epithelial cells (HK-2).

METHODS

RAPD carboxymethylation with a carboxyl group (-COOH) content of 3.57% was carried out by the chloroacetic acid solvent method. The effects of -COOH content in RAPs and RAP concentration on the regulation of CaOx crystal growth were studied by controlling the variables. Cell experiments were conducted to explore the differences in the cytotoxicity of RAP-regulated crystals.

RESULTS

The -COOH contents of RAPD, RAP1, RAP2, and RAP3 were 3.57%, 7.79%, 10.84%, and 15.33%, respectively. RAPs can inhibit the growth of calcium oxalate monohydrate (COM) and induce the formation of calcium oxalate dihydrate (COD). When the -COOH content in RAPs was high, their ability to induce COD formation was enhanced. In the crystals induced by RAPs, a high COD content can lower the damage to cells. In particular, the cytotoxicity of the crystals induced by RAP3 was the lowest. When the concentration of RAP3 increased, the cytotoxicity gradually increased due to the reduced size of the formed COD crystals. An interaction was observed between RAPs and crystals, and the number of RAPs adsorbed in the crystals was positively correlated with the -COOH content in RAPs.

CONCLUSIONS

RAPs can reduce the damage of CaOx to HK-2 cells by regulating the crystallization of CaOx crystals and effectively reducing the risk of kidney stone formation. RAPs, especially RAP3 with a high carboxyl group content, has the potential to be developed as a novel green anti-stone drug.

Purification, structural characterization and antioxidant activities of two neutral polysaccharides from persimmon peel

Two neutral polysaccharides (PPP1-1 and PPP1-2) were purified from persimmon peel. PPP1-1 (21.84 kDa) was mainly composed of arabinose (22.92 %), galactose (21.09 %), glucose (35.13 %), and xylose (19.09 %), while PPP1-2 (10.42 kDa) mainly contained arabinose (32.98 %), galactose (20.81 %), glucose (26.86 %), xylose (10.46 %), and mannose (7.63 %). Methylation and NMR spectra analysis demonstrated that the backbone of PPP1-1 appeared to be →6)-α-D-Glcp-(1→, →2,6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Manp-(1→, and α-L-Araf-(1 → residues. The main chain of PPP1-2 was composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →1,2)-α-D-Glcp-(6→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →4,6)-α-D-Glcp-(1→, and →4)-β-D-Manp-(1 → residues and terminal of α-L-Araf-(1 → residue. PPP1-2 exhibited stronger antioxidant activities and better thermal stability than PPP1-1. Our results provided the foundation for further investigating the structure and biological activities of persimmon peel polysaccharides and highlighted their potential to become potential antioxidants in functional food.

Structural characteristics and immunostimulatory activity of sea cucumber tendon polysaccharides in cyclophosphamide-induced Balb/c mice

Sea cucumber tendon, one of the main parts of sea cucumber viscera, is widely accepted as a waste residue. In this study, a sea cucumber tendon polysaccharide (SCTPII) was purified from sea cucumber tendons and its primary structures and immunomodulatory activity were investigated. SCTPII is a triple-helix conformation homogeneous polysaccharide with a molecular weight of 3.97 × 10⁶ Da that consists of glucose and fucose with molar ratios of 92.09% and 7.91% with high thermostability. In vivo tests on immunosuppressed Balb/c mice revealed that compared with the model group, the proliferation of T cells and B cells in splenic lymphocytes of mice in the high-dose group was significantly improved by 0.92 times and 5.14 times, respectively. Additionally, SCTPII could improve the proliferation ability and phagocytosis of macrophages, as well as promoting the expression of IL-6, TNF-α and IFN-γ and enhancing the intestinal physical barrier function by increasing the protein expression of claudin-1, occludin, ZO-1 and MUC2. Furthermore, the 16S rRNA sequencing of fecal samples was performed, and gene count and α-diversity analysis revealed that SCTPs could improve the microbial community richness. In particular, SCTPs could increase the relative abundance of Lactobacillus, Bacteroides and Akkermansia and reduce the relative abundance of Lachnospiraceae_NK4A136_group and Rikenellaceae_RC9_gut_group. These results demonstrate that SCPII possesses potential immunoregulatory activities in cyclophosphamide-induced mice by regulating intestinal microbiota diversity and improving immune organs, enhancing the proliferation ability of macrophages and splenocyte proliferation, and enhancing intestinal physical barrier function, which might provide important evidence for the development and utilization of the viscera of sea cucumber.

Mechanisms of Gynostemma pentaphyllum against non-alcoholic fibre liver disease based on network pharmacology and molecular docking

As a progressive chronic disease, the effective treatment for non‐alcoholic fibre liver disease (NAFLD) has not yet been thoroughly explored at the moment. The widespread use of Gynostemma pentaphyllum (Thunb) for its anti‐insulin resistance effect indicates that potential therapeutic value may be found in Thunb for NAFLD. Hence, this research aims to discover the latent mechanism of Thunb for NAFLD treatment. To achieve the goal of discovering the latent mechanism of Thunb for NAFLD treatment, molecular docking strategy integrated a network phamacology was adopted in the exploration. We acquire Thunb compounds with activeness from TCMSP database. We collect the putative targets of Thunb and NAFLD to generate the network. Key targets and mechanism are screened by PPI analysis, GO and KEGG pathway enrichment analyses. Molecular docking simulation is introduced into the study as assessment method. Through network analysis and virtual screening based on molecular docking, 2 targets (AKT 1 and GSK3B) are identified as key therapeutic targets with satisfying binding affinity. Main mechanism is believed to be the biological process and pathway related to insulin resistance according to the enrichment analyses outcomes. Particularly, the P13K–AKT signalling pathway is recognized as a key pathway of the mechanism. In conclusion, the study shows that Thunb could be a potential treatment against NAFLD and may suppress insulin resistance through the P13K–AKT signalling pathway. The result of the exploration provides a novel perspective for approaching experimental exploration.

Separation, Purification, Structural Characterization, and Anticancer Activity of a Novel Exopolysaccharide from Mucor sp

Mucor sp. has a wide range of applications in the food fermentation industry. In this study, a novel exopolysaccharide, labeled MSEPS, was separated from Mucor sp. fermentation broth through ethanol precipitation and was purified by ion-exchange chromatography, as well as gel filtration column chromatography. MSEPS was composed mostly of mannose, galactose, fucose, arabinose, and glucose with a molar ratio of 0.466:0.169:0.139:0.126:0.015 and had a molecular weight of 7.78 × 10⁴ Da. The analysis of methylation and nuclear magnetic resonance results indicated that MSEPS mainly consisted of a backbone of →3,6)-α-d-Manp-(1→3,6)-β-d-Galp-(1→, with substitution at O-3 of →6)-α-d-Manp-(1→ and →6)-β-d-Galp-(1→ by terminal α-l-Araf residues. MTT assays showed that MSEPS was nontoxic in normal cells (HK-2 cells) and inhibited the proliferation of carcinoma cells (SGC-7901 cells). Additionally, morphological analysis and flow cytometry experiments indicated that MSEPS promoted SGC-7901 cell death via apoptosis. Therefore, MSEPS from Mucor sp. can be developed as a potential antitumor agent.

Structure characterization, antioxidant capacity, rheological characteristics and expression of biosynthetic genes of exopolysaccharides produced by Lactococcus lactis subsp. lactis IMAU11823

Exopolysaccharides (EPSs) from lactic acid bacteria have special functions and complex structures, but the function and structure of EPSs of the important dairy starter, Lactococcus (L.) lactis subsp. lactis, are less known. This study investigated the cytotoxicity, antioxidant capacities, rheological characteristics, chemical structure and expression of biosynthetic genes of EPSs of the L. lactis subsp. lactis IMAU11823. The EPSs showed strong reducing power and no cytotoxicity. EPS-1 comprised glucose and mannose (molar ratio of 7.01: 1.00) and molecular weight was 6.10 × 10⁵ Da, while EPS-2 comprised mannose, glucose and rhamnose (7.45: 1.00: 2.34) and molecular weight was 2.93 × 10⁵ Da. EPS-1 was a linear structure comprised two sugar residues, while EPS-2 was more complex, non-linear, and comprised eight sugar residues. In additions, our study proposed an EPS biosynthesis model for the IMAU11823 strain. The current findings have broadened the understanding of the formation, structure and function of complex EPSs of IMAU11823.

Structural characterization of a pure polysaccharide from Bletilla striata tubers and its protective effect against H2O2-induced injury fibroblast cells

The present study investigated the structural characteristics and its protective effect against H₂O₂-induced injury fibroblast cells of Bletilla striata tuber polysaccharide. The polysaccharides were gently extracted by water and recovered using the method of alcohol precipitation, and after further purification by DEAE-Sepharose Fast Flow gel column, a pure polysaccharide (pBSP) was finally obtained. The structural characterization of pBSP were investigated by using periodate oxidation studies, Smith-degradation, FT-IR spectroscopy, 1D and 2D NMR spectroscopy. The antioxidant effect of pBSP was evaluated by inhibiting the production of reactive oxygen species (ROS) in human fibroblast model cells induced by H₂O₂. It was firstly reported that pBSP was composed of d-glucose and D-mannose in a molar ratio of 1.00:1.34 with a molecular weight of 327.6 kDa. The repeating units of pBSP contained (1 → 4)-linked-β-D-Manp, (1 → 4)-linked-α-D-Glcp and (1 → 3)-linked-β-D-Manp, and there was no branched chain. pBSP exhibited no toxic effect on fibroblasts cells and could protect them against H₂O₂-induced injuries. After pretreatment with pBSP for 24 h, the content of ROS in fibroblasts decreased significantly. These results not only confirm the availability B. striata, but also indicate that pBSP have potential antioxidant capacity. Our observations can provide foundation for further development of pBSP-based cosmetics.

Isolation, Purification, Characterization, and Immunomodulatory Activity Analysis of α-Glucans from Spirulina platensis

Crude polysaccharides from Spirulina platensis (SP) were isolated by maceration with a hot alkali solution and further fractionated by DEAE-52 cellulose and Sephadex G-100 chromatography into two purified fractions PSP-1 and PSP-2. The monosaccharide composition analysis indicated that SP was mainly composed of rhamnose and glucose, while PSP-1 and PSP-2 were composed only of glucose. The composition analysis of PSP-1 and PSP-2 by HPLC, FT-IR, and NMR showed that PSP-1 and PSP-2 were branching dextran, and their structures were (1 → 4)-linked-α-D-Glcp as the main chain, and C-6 replaced the single α-D-Glcp as the linear structure of the branch chain. The glucans (SP/PSP-1/PSP-2) can significantly improve the phagocytic ability of macrophages, enhance iNOS activity, promote NO production, and increase IL-6 mRNA expression, so they may possess certain immunomodulatory activity.

Structural characterization and immunomodulatory activity of intracellular polysaccharide from the mycelium of Paecilomyces cicadae TJJ1213

Two intracellular polysaccharide fractions (IPS1 and IPS2) were obtained from the mycelium of Paecilomyces cicadae TJJ1213, and the structures were conducted. Results showed that they were homogenous with the average molecular weight of 2.40 × 10⁶ Da and 6.79 × 10⁵ Da. Two fractions were composed of mannose, glucose and galactose with molar ratios of 1.35: 6.93: 1.0 and 2.04: 1.0: 1.87, respectively. The backbone of IPS1 was → 4)-α-D-Glcp (1 → and → 3,4)-α-D-Manp (1 → residues with a side chain consisted of T-α-D-Galp. IPS2 was consisted of → 4)-α-D-Glcp-(1→, →3,4)-α-D-Manp-(1 → and → 2,6)-α-D-Manp-(1 → residues and the branches were also consisted of T-α-D-Galp. In addition, the scanning electron microscope and atomic force microscope images presented different features of IPS1 and IPS2, respectively. Furthermore, two fractions exhibited better immunomodulatory effects. They could markedly promote the proliferation of RAW264.7 cells and enhance phagocytosis, nitric oxide release and cytokines production. These results indicated that IPS1 and IPS2 had potential to enhance immune responses.

Herbal therapy for ameliorating nonalcoholic fatty liver disease via rebuilding the intestinal microecology

The worldwide prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, and this metabolic disorder has been recognized as a severe threat to human health. A variety of chemical drugs have been approved for treating NAFLD, however, they always has serious side effects. Chinese herbal medicines (CHMs) have been widely used for preventing and treating a range of metabolic diseases with satisfactory safety and effective performance in clinical treatment of NAFLD. Recent studies indicated that imbanlance of the intestinal microbiota was closely associated with the occurrence and development of NAFLD, thus, the intestinal microbiota has been recognized as a promising target for treatment of NAFLD. In recent decades, a variety of CHMs have been reported to effectively prevent or treat NAFLD by modulating intestinal microbiota to further interfer the gut-liver axis. In this review, recent advances in CHMs for the treatment of NAFLD via rebuilding the intestinal microecology were systematically reviewed. The key roles of CHMs in the regulation of gut microbiota and the gut-liver axis along with their mechanisms (such as modulating intestinal permeability, reducing the inflammatory response, protecting liver cells, improving lipid metabolism, and modulating nuclear receptors), were well summarized. All the knowledge and information presented here will be very helpful for researchers to better understand the applications and mechanisms of CHMs for treatment of NAFLD.

New dammarane-type glycosides from Gynostemma pentaphyllum and their lipid-lowering activity

Gynostemma pentaphyllum (Thunb.) Makino has a long history as food and diary supplement in China. At present, there are some products for hyperlipidemia in the market, including G. pentaphyllum tea, healthy wine and healthy food. In order to discover proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fourteen new triterpenoid saponins named gypenoside LXXXVIII-CI (1-14) along with six known compounds (15-20) were isolated from G. pentaphyllum. Their structures were elucidated by means of various spectroscopic techniques. Eight isolates were evaluated the inhibitory effect on PCSK9 in HepG2 cells. The results showed that three dammarane-type glycosides (2, 3, 15) remarkably reduced PCSK9 expression at 10 μM concentration. These findings suggested that G. pentaphyllum was worthy of further investigation to find small molecule PCSK9 inhibitors and facilitate their utilization as functional food ingredients.

Mechanism of gypenosides of Gynostemma pentaphyllum inducing apoptosis of renal cell carcinoma by PI3K/AKT/mTOR pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Gynostemma pentaphyllum (Thunb.) Makino is a traditional medicine commonly used in China, East Asia and Southeast Asia. In clinic, it is mainly used for hyperlipidemia and antitumor. Its antitumor activity was first recorded in "Illustrated Catalogue of Plants". Gypenosides were the main active ingredients of G. pentaphyllum. The anticancer activity of gypenosides in vivo and in vitro had been widely reported. However, the mechanism of gypenosides in renal cell carcinoma (RCC) still unclear.

AIM OF THE STUDY

In this study, we tried to investigate the active constituents from G. pentaphyllum and potential mechanisms in RCC treatment through network pharmacology and in vitro experiments.

MATERIAL/METHODS

Active compounds and their targets were evaluated and screened through TCMSP and Swiss Target Prediction database. Notably, nine preliminary screened components obtained from database were identified by LC-MS and LC-MS/MS. The targets associated with RCC were obtained from OMIM, TTD and GeneCards database. The PPI network and active component/target/pathway networks were constructed to identify the potential drug targets using String database and Cytoscape software. The functions and pathways of targets were analyzed through DAVID database. Finally, AutoDockTools 1.5.6 was used for molecular docking to assess the binding ability between compounds and targets. To support our prediction, we then explore the antitumor effect and mechanism of gypenosides by vitro experiments. CCK8 and flow cytometry were performed to evaluate cell death treated with gypenosides. Quantitative real-time PCR and Western blot were conducted to detect the changes of PI3K/AKT/mTOR signaling pathway.

RESULTS

Nine saponins and 68 targets have been screened. The hub targets covered PIK3CA, VEGFA, STAT3, JAK2, CCND1 and MAPK3. Enrichment analysis showed that the pathways mainly contained PI3K/Akt/mTOR, HIF-1, TNF, JAK-STAT and MAPK signaling pathways. Gypenosides extracted from G. pentaphyllum showed strong activity against 786-O and Caki-1 cells, and cell apoptosis were detected through Annexin V/PI dual staining assay. RT-qPCR showed that gypenosides downregulated the levels of PIK3CA, Akt and mTOR in Caki-1 and 786-O cells. Mechanistically, gypenosides induced apoptosis of RCC cells through regulating PI3K/Akt/mTOR signaling pathway which was implemented though decreasing the phosphorylation level of Akt and mTOR.

CONCLUSIONS

Gypenosides induced apoptosis of RCC cells by modulating PI3K/Akt/mTOR signaling pathway.

Purification, characterization and anti-atherosclerotic effects of the polysaccharides from the fruiting body of Cordyceps militaris

Hyperlipidemia is one major cause of atherosclerosis, which is a basic pathological change of cardiovascular diseases. Polysaccharide is a water-soluble component with lipid-lowering effects. In this study, alkaline-extracted polysaccharides were obtained from the fruiting body of C. militaris. Polysaccharides were purified via anion exchange and size exclusion chromatography. Their structural characteristics were investigated via chemical and spectroscopic methods. CM3I was mainly composed of →4)α-D-Glcp(1 → glycosyls and differed from starch due to the presence of →4,6)β-D-Glcp(1 → glycosyls. CM3II was characterized by its backbone, which was composed of →4)-β-D-Manp(1 → 6)-α-D-Manp(1 → 6)-β-D-Manp(1 → linked glycosyls, and especially the presence of O-methyl. Moreover, CM3II exhibited powerful anti-atherosclerotic effects via lowering plasma lipid levels in apolipoprotein E-deficient mice. The underlying mechanisms were attributed to its promoting effect on LXRα and inhibitory effect on SREBP-2. Collectively, CM3I and CM3II are different from the previously reported polysaccharides from C. militaris, and CM3II has a potential application in hypolipidemia and anti-atherosclerosis.

Purification, structural characterization, and PCSK9 secretion inhibitory effect of the novel alkali-extracted polysaccharide from Cordyceps militaris

One novel alkali-extracted polysaccharide, CM3-SII, was obtained from the fruiting body of C. militaris via column chromatography. Its structural characteristics were investigated via chemical and spectroscopic methods. The backbone of CM3-SII was composed of →4)-β-D-Manp(1→, →6)-β-D-Manp(1→, and →6)-α-D-Manp(1→ glycosyls, and branching at the O-4 positions of →6)-β-D-Manp(1→ glycosyls with β-D-Galp, (1→2) linked-β-D-Galf, and →2,6)-α-D-Manp(1→ residues. Furthermore, O-6 and O-2 positions of the →2,6)-α-D-Manp(1→ residues were substituted with methyl and β-D-Galp, respectively. This polysaccharide significantly enhanced the intracellular protein expression of low-density lipoprotein receptor and proprotein convertase subtilisin/kexin type 9 (PCSK9) via regulating sterol regulatory element-binding protein 2 in hepatoma Huh7 cells. Of note, CM3-SII significantly decreased PCSK9 secretion at the concentration of 200 μg/mL. Collectively, CM3-SII is different from the previously reported alkali-extracted polysaccharides isolated from the fruiting body of C. militaris, and it may have potential application in hypolipidemia or as a pharmaceutical additive.

Dammarane-Type Saponins from Gynostemma pentaphyllum Prevent Hypoxia-Induced Neural Injury through Activation of ERK, Akt, and CREB Pathways

Gynostemma pentaphyllum possesses neuroprotective bioactivity. However, the effect of gypenosides on hypoxia-induced neural damage remains obscure. In this study, Gyp, the active fraction extracted from G. pentaphyllum and its bioactive compounds as well as the underlying molecular mechanisms were investigated. Eighteen dammarane-type saponins were isolated from Gyp. The absolute configurations of six unreported compounds (13-18) were assessed via electron capture detection (ECD) analyses. The results of cell viability assay showed that Gyp and its bioactive compounds (13-16 and 18) effectively protected PC12 cells from hypoxia injury. Gyp pretreatment also improved mice spatial memory impairment caused by hypoxia exposure. At the molecular level, Gyp and its bioactive compounds could activate the signaling pathways of ERK, Akt, and CREB in vitro and in vivo. In summary, Gyp and its bioactive compounds could prevent hypoxia-induced injury via ERK, Akt, and CREB signaling pathways.

Medicinal Value and Potential Therapeutic Mechanisms of Gynostemma pentaphyllum (Thunb.) Makino and Its Derivatives: An Overview

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Gynostemma pentaphyllum (Thunb.) Makino (GpM) and its derivatives, especially gypenosides (Gyps), are widely used as safe and convenient natural herbal drugs for the treatment of many diseases for a long time, and Gyps have different oral bioavailability (OB) values and low ability to cross the blood-brain barrier (BBB). The effects of GpM and isolates on fibrosis, inflammation, oxidation, proliferation and migration are proved. GpM shows bidirectional regulation effect on proliferation, oxidation and apoptosis in tumor and non-tumor cells. GpM and its extractions can resist proliferation, activate oxidation and apoptosis in tumor cells and have opposite effects on non-tumor cells. We succinctly present some current views of medicinal value and potential therapeutic mechanisms of GpM and its derivatives.

Purification, structural elucidation and in vivo immunity-enhancing activity of polysaccharides from quinoa (Chenopodium quinoa Willd.) seeds

Quinoa crude polysaccharides (QPS) were extracted from Chenopodium quinoa Willd. The soluble non-starch polysaccharide fraction (QPS1) was subsequently purified by DEAE-52 cellulose and Sephadex G-50 gel chromatography, using QPS as raw materials. Its chemical structure was identified using FT-IR, NMR, AFM, SEM and Congo red staining. High performance gel permeation chromatography (HPGPC) was used to determine molecular weight, and composition by HPLC. QPS1, with a molecular weight of 34.0 kDa, was mainly composed of mannose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose at a molar ratio of 2.63:2.40:1.64:6.28:1.95:2.48:5.01. In addition, we evaluated the ameliorative effects of QPS1 on the improvement of anti-cyclophosphamide (CTX)-induced immunosuppression in ICR mice. The result exhibited significantly immune-enhancing activity: QPS1 successfully improved the content of IFN-γ, IL-6, IFN-ɑ, IgM and lysozyme (LYSO) in serum for three weeks, enhanced the phagocytic function of mononuclear macrophages and ameliorated delayed allergy in mice.

Purification, structural elucidation and anti-inflammatory activity in vitro of polysaccharides from Smilax china L

Smilax china L. is a traditional Chinese medicine mainly used for the treatment of pelvic inflammation. Polysaccharide might be one of the anti-inflammatory components of Smilax china L. Based on this hypothesis, this work aimed at extraction, purification and structural elucidation of Smilax china L. polysaccharides and their preliminary anti-inflammatory effects were also studied. Two polysaccharides named SCLP1 (Smilax china L. polysaccharide 1, 42.1kDa) and SCLP3-2 (Smilax china L. polysaccharide 3-2, 16.8kDa) were for the first time purified from Smilax china L. The structures of SCLP1 and SCLP3-2 were elucidated by chemical and spectral analysis. The results revealed that SCLP1 was a neutral polysaccharide composed of glucose and mannose (54.5:1.0). Its backbone was 1,4‑linked α‑Glcp interspersed with 1,2‑linked α‑Glcp and Manp; the branches were 1,6‑linked α-Glcp and terminated with α‑Glcp. SCLP3-2 was composed of galacturonic acid, arabinose, galactose and rhamnose (23.3:2.1:1.7:1.0) and was a pectin-type polysaccharide with an α‑1,4‑linked homogalacturonan backbone which was partially methyl-esterified and slightly acetylated. The side chains consisted of α‑Rhap, β‑Galp and α‑Araf. SCLP1 and SCLP3-2 could inhibit the production of NO, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells via NF-κB and MAPKs (ERK1/2, JNK) pathways, indicating that they possessed a potential anti-inflammatory activity.

Isolation, Structures, and Bioactivities of the Polysaccharides from Gynostemma pentaphyllum (Thunb.) Makino: A Review

Polysaccharides obtained from Gynostemma pentaphyllum (Thunb.) Makino have promising prospects in functional food and nutraceuticals due to its broad range of biological activities including antioxidant, immunomodulatory, antitumor, hepatoprotective, neuroprotective, and antifatigue activities. These beneficial biological activities are related to chemical composition and structure of the G. pentaphyllum polysaccharides. The molecular weight, monosaccharide composition, and chemical structures could be influenced by both different extraction/purification techniques employed to obtain polysaccharide enriched products. The purpose of this article is to review previous and current literature regarding the extraction, purification, structural characterization, and biological activity of G. pentaphyllum polysaccharides. This review provides a useful bibliography for the further investigation, production, and application of G. pentaphyllum polysaccharides as functional foods and nutraceuticals.

Structural characteristics and bioactive properties of a novel polysaccharide from Flammulina velutipes

A new water-soluble polysaccharide (FVP1) was extracted from Flammulina velutipes by traditional method "water extraction and alcohol precipitation" and purified by column chromatography. Physicochemical characterization showed that FVP1 was a homogeneous polysaccharide with a relative molecular weight of 54.78 kDa. It is composed of mannose (7.74%), glucose (70.41%), and galactose (16.38%). FVP1 (1000 mg/mL) possessed significant immune activity by increasing the secretion of nitric oxide (NO), tumour necrosis factor-α (TNF-α) (3183 ± 133.84 pg/mL), interleukin (IL)-6 (1133.21 ± 39.05 pg/mL), and IL-12 (579.96 ± 74.53 pg/mL) in macrophages. Furthermore, FVP1 showed significant hepatitis B surface antibody (anti-HBV) activity through reducing the expression of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA replication. These results suggest a novel role for FVP1 to be applied as an immunomodulators in dietary supplements to prevent HBV infection.

A new heteropolysaccharide from the seed husks of Plantago asiatica L. with its thermal and antioxidant properties

A new heteropolysaccharide (PMH) with a molecular weight of 1.4 × 10³ kDa was isolated from the seed husks of Plantago asiatica L. The monosaccharide composition of PMH was determined as glucose, xylose, arabinose, rhamnose, galactose and galacturonic acid with a molar ratio of 1.0 : 1.8 : 2.4 : 3.8 : 4.9 : 8.5. The backbone of PMH consisted of 1,4-β-d-GalpA with the side chains mainly composed of 1,3-α-d-Galp and 1,2-α-d-Galp which were attached to the O-3 of GlapA. The thermal analysis using the Flynn-Wall-Ozawa (FWO) method revealed that PMH had an apparent activation energy (E_a) of 173.1 kJ mol^-1. PMH experienced a major decomposition during the heating process at a temperature of 91.1 °C with a dry weight loss of 31.1%. Moreover, PMH exhibited stronger antioxidant ability than commercial psyllium, partially due to its higher content of uronic acid. The results suggested that PMH could be used in functional foods due to its structural, thermal and antioxidant characteristics.

Bioassay-guided isolation and identification of anticancer and antioxidant compounds from Gynostemma pentaphyllum (Thunb.) Makino

Gynostemma pentaphyllum (Thunb.) Makino is a medicinal and edible plant in China whose buds and leaves are used for making a popular kind of tea drink. The anticancer and antioxidant properties of the ethyl acetate (EA) and n-butanol (n-Bu) fractions provide a basis for conducting experiments for isolation and identification of key compounds that may be responsible for the aforementioned properties of G. pentaphyllum. Four compounds were isolated from the two fractions using ODS packing column, silica gel column, polyamide column, Sephadex LH-20 gel column and HPLC. With the aid of ¹H, ¹³C NMR and mass spectrometry, they were identified as 3,4-dihydroxy phenyl-O-β-d-glucoside, gypenoside XLVI, gypenoside L and ginsenoside Rd. 3,4-Dihydroxy phenyl-O-β-d-glucoside showed the strongest DPPH (97.23%) and ABTS (101.37%) scavenging effect and ferric ion reducing power (FRAP value 0.8846), which may be closely related to the hydrogen atoms of phenolic hydroxyls. Gypenoside L and ginsenoside Rd displayed the highest inhibition of tumor cell proliferation of A549 and MCF-7 cell lines, which had to do with the chemical structure of the compounds bearing glycosylated parts and free hydroxyls at the 20th or 21st carbon atom of dammarane-type saponin.

Gynostemma pentaphyllum (Thunb.) Makino is a medicinal and edible plant in China whose buds and leaves are used for making a popular kind of tea drink.

Triterpenes derived from hydrolyzate of total Gynostemma pentaphyllum saponins with anti-hepatic fibrosis and protective activity against H2O2-induced injury

Gynostemma pentaphyllum is a popular functional food, and it is also used as a traditional medicine in Asia. In this study, five previously undescribed triterpenes, gypensapogenin M, gypensapogenin N, gypensapogenin O, gypensapogenin P, and gypensapogenin Q, together with five known compounds were isolated from the hydrolyzate of total G. pentaphyllum saponins. The bioassay data showed that all the triterpenes exhibited significant protective activity against H₂O₂-induced myocardial cell injury and anti-hepatic fibrosis activity. Taken together, the discovery of these triterpenes from the hydrolyzate of total G. pentaphyllum saponins expands its use as a functional food for preventing myocardial injury and liver fibrosis.

Further New Gypenosides from Jiaogulan (Gynostemma pentaphyllum)

Jiaogulan (Gynostemma pentaphyllum) has been widely used as a herbal tea, dietary supplement, and vegetable in Asian countries. In this study, six new gypenosides (1-6) were isolated from the aerial parts of G. pentaphyllum. Their molecular structures were elucidated through spectroscopic analysis and acid hydrolysis. Gypenosides 1 and 2 represented the first example of a dammar-21-O- glucopyranoside without any unsaturated functional group and a dammar-3-O-glucopyranosyl-25-O-glucopyranoside without any cyclization in the side chain, respectively. In addition, gypenosides 5 and 6 exhibited the first example of a 24-hydroperoxy-19-oxo-dammarane triterpenoid and 19-oxo-dammar-21-O-glucopyranoside with a saturated side chain, respectively. Gypenoside 5 was found to possess protein tyrosine phosphatase 1B inhibitory activity, with an IC₅₀ value of 8.2 ± 0.9 μM, and moderate cytotoxicity against human breast cancer cells MCF7, MCF7/ADR, and MDA-MB-231, with IC₅₀ values ranging from 10.5 ± 1.4 to 14.2 ± 2.6 μM. The outcome of the study provided crucial information regarding the structural diversity and health benefits of gypenosides.