Polysaccharides from Aconitum carmichaelii leaves: Structure, immunomodulatory and anti-inflammatory activities

Extraction, characterization and intestinal anti-inflammatory and anti-oxidative activities of polysaccharide from stems and leaves of Chuanminshen violaceum M. L. Sheh & R. H. Shan

ETHNOPHARMACOLOGICAL RELEVANCE

Chuanminshen violaceum M. L. Sheh & R. H. Shan (CV) is used as a medicine with roots, which have the effects of benefiting the lungs, harmonizing the stomach, resolving phlegm and detoxifying. Polysaccharide is one of its main active components and has various pharmacological activities, but the structural characterization and pharmacological activities of polysaccharide from the stems and leaves parts of CV are still unclear.

AIM OF THE STUDY

The aim of this study was to investigate the optimal extraction conditions for ultrasound-assisted extraction of polysaccharide from CV stems and leaves, and to carry out preliminary structural analyses, anti-inflammatory and antioxidant effects of the obtained polysaccharide and to elucidate the underlying mechanisms.

MATERIALS AND METHODS

The ultrasonic-assisted extraction of CV stems and leaves polysaccharides was carried out, and the response surface methodology (RSM) was used to optimize the extraction process to obtain CV polysaccharides (CVP) under the optimal conditions. Subsequently, we isolated and purified CVP to obtain the homogeneous polysaccharide CVP-AP-I, and evaluated the composition, molecular weight, and structural features of CVP-AP-I using a variety of technical methods. Finally, we tested the pharmacological activity of CVP-AP-Ⅰ in an LPS-induced model of oxidative stress and inflammation in intestinal porcine epithelial cells (IPEC-J2) and explored its possible mechanism of action.

RESULTS

The crude polysaccharide was obtained under optimal extraction conditions and subsequently isolated and purified to obtain CVP-AP-Ⅰ (35.34 kDa), and the structural characterization indicated that CVP-AP-Ⅰ was mainly composed of galactose, galactose, rhamnose and glucose, which was a typical pectic polysaccharide. In addition, CVP-AP-Ⅰ attenuates LPS-induced inflammation and oxidative stress by inhibiting the expression of pro-inflammatory factor genes and proteins and up-regulating the expression of antioxidant enzyme-related genes and proteins in IPEC-J2, by a mechanism related to the activation of the Nrf2/Keap1 signaling pathway.

CONCLUSION

The results of this study suggest that the polysaccharide isolated from CV stems and leaves was a pectic polysaccharide with similar pharmacological activities as CV roots, exhibiting strong anti-inflammatory and antioxidant activities, suggesting that CV stems and leaves could possess the same traditional efficacy as CV roots, which is expected to be used in the treatment of intestinal diseases.

Paotianxiong polysaccharides potential prebiotics: Structural analysis and prebiotic properties

Paotianxiong (PTX) is a processing product of Aconitum carmichaelii Debx., often used as a tonic food daily. However, the structure and activity of the polysaccharide component that plays a major role still need to be determined. In our work, two new polysaccharides were purified from PTX and named PTXP-1 and PTXP-2. Structural analysis showed that PTXP-1 is a glucan with a molecular weight of 915 Da and a structure of 4)-α-D-Glcp-(1 → as the main chain. PTXP-2 is a glucose arabinoglycan with 4)-α-D-Glcp-(1 → as the main chain, containing 8 glycosidic bonds attached, and a molecular weight of 57.9KDa. In vitro probiotic experiments demonstrated that PTXP-1 could significantly promote probiotic growth and acid production. In vivo experiments demonstrated that both PTXP-1 and PTXP-2 exhibited significant effectiveness in promoting the growth of intestinal probiotics. These findings help expand the application of polysaccharide components extracted from tonic herbs as functional food ingredients.

Polysaccharides from Balanophora harlandii Hook: Isolation, characterization, and anti-inflammation activities

Balanophora harlandii Hook (B. harlandii), a folk medicine, has been traditionally employed to treat traumatic bleeding, gastroenteritis, icteric hepatitis, hemorrhoids, and other conditions. In this work, polysaccharides with anti-inflammatory effects were extracted from B. harlandii and purified. The extraction conditions were optimized, and the properties of one purified neutral fraction, denoted as BHPs-W-S3, were analyzed. BHPs-W-S3 has a molecular weight of 14.1 kDa, and its three main monosaccharides are glucose, galactose, and xylose, with a molar ratio of 6.4:1.7:1.1. Its main chain consists of →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, →6)-β-D-Galp-(1→, →3,6)-β-D-Galp-(1→, and it has branch chains at the O-4 and/or O-3 positions. In addition, in vitro experiments showed that the polysaccharides from B. harlandi can decrease the phosphorylation level of p65 and IκBα in LPS-induced RAW264.7 cells to reduce the expression of the pro-inflammatory genes such as TNF-α, IL-6, and IL-1β.

The Isolation, Structural Characterization and Anti-Inflammatory Potentials of Neutral Polysaccharides from the Roots of Isatis indigotica Fort

Polysaccharides have been assessed as a potential natural active component in Chinese herbal medicine with anti-inflammatory properties. However, the complex and indefinite structures of polysaccharides limit their applications. This study explains the structures and anti-inflammatory potentials of three neutral polysaccharides, RIP-A1 (Mw 1.8 × 104 Da), RIP-B1 (Mw 7.4 × 104 Da) and RIP-B2 (Mw 9.3 × 104 Da), which were isolated from the roots of Isatis indigotica Fort. with sequenced ultrafiltration membrane columns, DEAE-52 and Sephadex G-100. The planar structures and microstructures of RIP-A1, RIP-B1 and RIP-B2 were further determined by HPGPC, GC-MS, methylation analysis, FT-IR, SEM and AFM, in which the structure of RIP-A1 was elucidated in detail using 1D/2D NMR. The Raw 264.7 cells were used for the anti-inflammatory activity in vitro. The results showed that RIP-A1, RIP-B1 and RIP-B2 are all neutral polysaccharides, with RIP-A1 having the smallest Mw and the simplest monosaccharide composition of the three. RIP-A1 is mainly composed of Ara and Gal, except for a small quantity of Rha. Its main structure is covered with glycosidic linkages of T-α-Araf, 1,2-α-Rhap, 1,5-α-Araf, T-β-Galp, 1,2,4-α-Rhap, 1,3,5-α-Araf and 1,6-β-Galp with 0.33:0.12:1.02:0.09:0.45:11.41:10.23. RIP-A1 significantly inhibited pro-inflammatory cytokines (NO, TNF-α, IL-6 and IL-1β) and increased anti-inflammatory cytokines (IL-4) in LPS-stimulated RAW 264.7 cells. Moreover, RIP-A1 could significantly inhibit the mRNA expression of TNF-α, IL-6 and L-1β. It could also activate IKK, p65 and IκBα (the components of the NF-κB signaling pathway). In conclusion, the above results show the structural characterization and anti-inflammatory potentials of RIP-A1 as an effective natural anti-inflammatory drug.

Extraction, structures, biological effects and potential mechanisms of Momordica charantia polysaccharides: A review

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103-1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L.

Comparative transcriptome revealed the molecular responses of Aconitum carmichaelii Debx. to downy mildew at different stages of disease development

BACKGROUND

Aconitum carmichaelii Debx. has been widely used as a traditional medicinal herb for a long history in China. It is highly susceptible to various dangerous diseases during the cultivation process. Downy mildew is the most serious leaf disease of A. carmichaelii, affecting plant growth and ultimately leading to a reduction in yield. To better understand the response mechanism of A. carmichaelii leaves subjected to downy mildew, the contents of endogenous plant hormones as well as transcriptome sequencing were analyzed at five different infected stages.

RESULTS

The content of 3-indoleacetic acid, abscisic acid, salicylic acid and jasmonic acid has changed significantly in A. carmichaelii leaves with the development of downy mildew, and related synthetic genes such as 9-cis-epoxycarotenoid dioxygenase and phenylalanine ammonia lyase were also significant for disease responses. The transcriptomic data indicated that the differentially expressed genes were primarily associated with plant hormone signal transduction, plant-pathogen interaction, the mitogen-activated protein kinase signaling pathway in plants, and phenylpropanoid biosynthesis. Many of these genes also showed potential functions for resisting downy mildew. Through weighted gene co-expression network analysis, the hub genes and genes that have high connectivity to them were identified, which could participate in plant immune responses.

CONCLUSIONS

In this study, we elucidated the response and potential genes of A. carmichaelii to downy mildew, and observed the changes of endogenous hormones content at different infection stages, so as to contribute to the further screening and identification of genes involved in the defense of downy mildew.

Unlocking the hidden potential: Enhancing the utilization of stems and leaves through metabolite analysis and toxicity assessment of various parts of Aconitum carmichaelii

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii is widely used in traditional Chinese medicine clinics as a bulk medicinal material. It has been used in China for more than two thousand years. Nevertheless, the stems and leaves of this plant are usually discarded as non-medicinal parts, even though they have a large biomass and exhibit therapeutic properties. Thus, it is crucial to investigate metabolites of different parts of Aconitum carmichaelii and explore the relationship between metabolites and toxicity to unleash the utilization potential of the stems and leaves.

AIM OF THE STUDY

Using plant metabolomics, we aim to correlate different metabolites in various parts of Aconitum carmichaelii with toxicity, thereby screening for toxicity markers. This endeavor seeks to offer valuable insights for the development of Aconitum carmichaelii stem and leaf-based applications.

MATERIALS AND METHODS

UHPLC-Q-Orbitrap MS/MS-based plant metabolomics was employed to analyze metabolites of the different parts of Aconitum carmichaelii. The cardiotoxicity and hepatotoxicity of the extracts from different parts of Aconitum carmichaelii were also investigated using zebrafish as animal model. Toxicity markers were subsequently identified by correlating toxicity with metabolites.

RESULTS

A total of 113 alkaloids were identified from the extracts of various parts of Aconitum carmichaelii, with 64 different metabolites in stems and leaves compared to daughter root (Fuzi), and 21 different metabolites in stems and leaves compared to mother root (Wutou). The content of aporphine alkaloids in the stems and leaves of Aconitum carmichaelii is higher than that in the medicinal parts, while the content of the diester-diterpenoid alkaloids is lower. Additionally, the medicinal parts of Aconitum carmichaelii exhibited cardiotoxicity and hepatotoxicity, while the stems and leaves have no obvious toxicity. Finally, through correlation analysis and animal experimental verification, mesaconitine, deoxyaconitine, and hypaconitine were used as toxicity markers.

CONCLUSION

Given the low toxicity of the stems and leaves and the potential efficacy of aporphine alkaloids, the stems and leaves of Aconitum carmichaelii hold promise as a valuable medicinal resource warranting further development.

Screening and characterization of an anti-inflammatory pectic polysaccharide from Cucurbita moschata Duch

Pectin polysaccharides have demonstrated diverse biological activities, however, the inflammatory potential of pectin polysaccharides extracted from Cucurbita moschata Duch remains unexplored. This study aims to extract, characterize and evaluate the effects of pumpkin pectin polysaccharide on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and dextran sulfate sodium (DSS)-induced colitis in mice, along with its underlying mechanism of action. Initially, we extracted three fractions of pectin polysaccharides from pumpkin and screened them for anti-inflammatory activity in LPS-induced macrophages, identifying CMDP-3a as the most potent anti-inflammatory fraction. Subsequently, CMDP-3a underwent comprehensive characterization through chromatography and spectroscopic analysis, revealing CMDP-3a as an RG-I-HG type pectin polysaccharide with →4)-α-D-GalpA-(1 → and →4)-α-D-GalpA-(1 → 2,4)-α-L-Rhap-(1 → as the main chain. Further, in the LPS-induced RAW264.7 cells model, treatment with CMDP-3a significantly down-regulated the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) by inhibiting the MAPK and NF-κB signaling pathways. Finally, in a mouse colitis model, CMDP-3a administration obviously inhibited DSS-induced pathological alterations and reduced inflammatory cytokine expressions in the colonic tissues by down-regulating the TLR4/NF-κB and MAPK pathways. These findings provide a molecular basis for the potential application of CMDP-3a in reducing inflammatory responses.

Structural and in vivo-in vitro myocardial injury protection features of two novel polysaccharides from Allium macrostemon Bunge and Allium chinense G. Don

This study aimed to investigate the structural characteristics, in vivo antiatherosclerosis activity, and in vitro myocardial injury protection effects of polysaccharides from Allium macrostemon Bunge and Allium chinense G. Don. Thus, crude polysaccharides of Allium macrostemon Bunge and Allium chinense G. Don significantly reduced serum lipid levels, improved cardiac myocyte morphology and arrangement, and relieved the development of myocardial fibrosis. Meanwhile, the lesion areas of the aorta and aortic valve had evident visual improvements. Furthermore, two main novel purified polysaccharides, namely, AMB-1 and ACGD-1, were isolated and characterized from crude Allium macrostemon Bunge and Allium chinense G. Don fractions, respectively. The purified polysaccharides mainly consisted of fructose and glucose and had molecular weights of 25.22 and 19.53 kDa, respectively. In addition, Fourier transform infrared spectroscopy, methylation, and nuclear magnetic resonance data revealed the primary structures of the AMB1 (or ACGD1) backbone with branched side chains. Scanning electron microscope analysis showed that the purified polysaccharides were both piled together in a lamellar or clastic form with a smooth surface along with linear or irregular bulges. Moreover, the purified polysaccharides both showed nontoxicity on H9c2 cells and effectively dropped hypoxia/reoxygenation-induced apoptosis by the BCL-2/BAX pathway. Overall, the characterization of the structural properties and in vivo and in vitro myocardial injury protection effects of Allium macrostemon Bunge and Allium chinense G. Don polysaccharides enriched our understanding of their nutritional and medicinal values. To the best of our knowledge, this is the first study on the structural characteristics and bioactivities of Allium chinense G. Don polysaccharides.

Research progress in the preparation, structural characterization, and biological activities of polysaccharides from traditional Chinese medicine

Traditional Chinese medicines are tremendous sources of polysaccharides, which are of great interest in the human welfare system as natural medicines, food, and cosmetics. This review aims to highlight the recent trends in extraction (conventional and non-conventional), purification and analytic techniques of traditional Chinese medicine polysaccharides (TCMPs), and the chemical structure, biological activities (anti-tumor, hypoglycemic, antioxidant, intestinal flora regulation, immunomodulatory, anti-inflammatory, anti-aging, hypolipidemic, hepatoprotective, and other activities), and the underlying mechanisms of polysaccharides extracted from 76 diverse traditional Chinese medicines were compared and discussed. With this wide coverage, a total of 164 scientific articles were searched from the database including Google Scholar, PubMed, Web of Science, and China Knowledge Network. This comprehensive survey from previous reports indicates that TCMPs are non-toxic, highly biocompatible, and good biodegradability. Besides, this review highlights that TCMPs may be excellent functional factors and effective therapeutic drugs. Finally, the current problems and future research advances of TCMPs are also introduced. New valuable insights for the future researches regarding TCMPs are also proposed in the fields of therapeutic agents and functional foods.

Purification and structural characterization of two polysaccharides with anti-inflammatory activities from Plumbago zeylanica L

Plumbago zeylanica L., a traditional Chinese medicine, has anti-bacterial and anti-inflammatory effects, and it is critical important to explore the chemical compounds and evaluate their biological actions from the medicinal plant. However, the chemical structure and biological activities of polysaccharides from P. zeylanica. were still poorly understood. In this study, two water-soluble polysaccharides named WPZP-2-1 and WPZP-2-2 were purified from P. zeylanica L. Chemical and spectroscopic tests showed that the main chain of WPZP-2-1 was →4)-α-D-GalpA-(1 → 2)-α-L-Rhap-(1→, and the branch chain was galactose or arabinose. The main chain of WPZP-2-2 was composed of →4)-α-D-GalpA-(1 → 2)-α-L-Rhap-(1→, and the O-2 and O-3 of →4)-α-D-GalpA had a small amount of acetylation. In addition, in vitro test showed that WPZP-2-1 and WPZP-2-2 significantly improved the inflammatory damage of LPS + IFN-γ-induced THP-1 cells via reducing the protein levels of CD14, TLR4 and MyD88, thereby promoting IL-10 expression and inhibiting the mRNA levels of TNF-α and IL-1β. Those findings indicated that WPZP-2-1 and WPZP-2-2 from the plant should be served as the potential anti-inflammatory agents.

The structural characteristic of acidic-degraded polysaccharides from seeds of Plantago ovata Forssk and its biological activity

In this study, a response surface methodology (RSM) was used to determine the best combination for acid degradation parameters to reduce the viscosity of Plantago ovata Forssk seed polysaccharide (POFP). Then, the two major homogeneous polysaccharides (AH-POFP1 and AH-POFP3) were obtained by DEAE-650 M and Sephadex G-100 column chromatography. The apparent structure of the main fraction AH-POFP1 was characterized by SEM, TG and XRD, and the linkage of AH-POFP1 was determined by a combination of partial acidolysis, Smith's degradation, methylation analysis and 2D NMR analysis. Structural analysis showed that AH-POFP1 was mainly composed of xylose, with a molecular weight of 618.1 kDa, and had a backbone of 1 → 4-linked Xylp, as well as branches of T-linked Xylp, 1 → 4-linked Xylp attached to the O-2 position. The antioxidant activity assays showed that the both AH-POFP1 and AH-POFP3 possess strong scavenging radical ability. Moreover, AH-POFP1 inhibits the secretion of pro-inflammatory factors, and promotes the secretion of anti-inflammatory factors, thereby exerting anti-inflammatory effects. These findings may help to guide future applications of Plantago ovata Forssk in the fields of food, health care, and pharmacy.

Structural analysis of a soluble polysaccharide GSPA-0.3 from the root of Panax ginseng C. A. Meyer and its adjuvant activity with mechanism investigation

A novel polysaccharide (GSPA-0.3) was isolated and purified from the root of cultivated Panax ginseng C. A. Meyer, and its structure, adjuvant activities, and mechanisms for inducing the maturation of mouse dendritic 2.4 cells (DC2.4) were extensively studied. Fraction GSPA-0.3, mainly composed by the galacturonic acid, galactose, arabinose, glucose, rhamnose, mannose, and xylose, had a molecular weight of 62,722 Da. The main chain of GSPA-0.3 was composed of →3)-α-L-Rhap-(1→, →4)-α-D-GalpA-(1→, and →3, 4)-α-D-GalpA-(1→. Branched chains comprised α-L-Araf-(1→3, 5)-α-L-Araf-(1→5)-α-L-Araf-(1→, α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glcp-(1→, β-D-Galp-(1→4)-β-D-Galp-(1→4)-β-D-Galp-(1→, and α-D-GalpA-(1→ units connected to the C3 position of →3, 4)-α-D-GalpA-(1→. In vivo, GSPA-0.3 was found to stimulate the production of IgG, IgG1, and IgG2a; increase the splenocyte proliferation index; and promote the expression of GATA-3, T-bet, IFN-γ, and IL-4 in H1N1 vaccine-immunized mice. Moreover, GSPA-0.3 significantly increased the levels of neutralizing antibodies in the mice, and its adjuvant activity was found to be superior to aluminum adjuvant (Alum adjuvant). Mechanistic investigations showed that GSPA-0.3 activated the TLR4-dependent pathway by upregulating the expressions of TLR4, MyD88, TRAF-6, and NF-κB proteins and gens. The results presented herein suggested that GSPA-0.3 could significantly promote the efficacy of the H1N1 vaccine by modulating Th1/Th2 response via the TLR4-MyD88-NF-κB signaling pathway.

Bioactive polysaccharides in different plant parts of Aconitum carmichaelii

BACKGROUND

Aconitum carmichaelii is an industrially cultivated medicinal plant in China and its lateral and mother roots are used in traditional Chinese medicine due to the presence of alkaloids. However, the rootlets and aerial parts are discarded after collection of the roots, and the non-toxic polysaccharides in this plant have attracted less attention than the alkaloids and poisonous features. In this study, five neutral and 14 acidic polysaccharide fractions were isolated systematically from different plant parts of A. carmichaelii, and their structural features and bioactivity were studied and compared.

RESULTS

The neutral fraction isolated from the rootlets differed from those isolated from the lateral and mother roots. It consisted of less starch and more possible mannans, galactans, and/or xyloglucans, being similar to those of the aerial parts. Pectic polysaccharides containing homogalacturonan and branched type-I rhamnogalacturonan (RG-I) were present in all plant parts of A. carmichaelii. However, more arabinogalactan (AG)-II side chains in the RG-I backbone were present in the aerial parts of the plants, while more amounts of arabinans were found in the roots. Various immunomodulatory effects were observed, determined by complement fixation activity and anti-inflammatory effects on the intestinal epithelial cells of all polysaccharide fractions.

CONCLUSION

This study highlighted the diversity of polysaccharides present in A. carmichaelii, especially in the unutilized plant parts, and showed their potential medicinal value. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Structural elucidation of novel pro-inflammatory polysaccharides from Daphne mezereum L

Daphne mezereum L., an important medicinal plant in Scandinavian folk medicine, was used to treat ailments such as diarrhea, swelling and stomach pain. A range of natural compounds have been isolated, but little attention has been given to the polysaccharides in this plant. Previous work in our group have shown that a polysaccharide enriched fraction from the bark of D. mezereum exhibited pro-inflammatory effects. To pursue this further, the aim of the present work was to isolate and characterize these polysaccharides. From the ethanol-precipitate of a water extract, one neutral (DMP-NF) and one acidic (DMP-AF) fraction was isolated by anion-exchange chromatography. GC, GC-MS and 1D- and 2D-NMR were used to characterize the polysaccharide structures. DMP-NF appeared to be a mixture of arabinan, arabinogalactan and hemicelluloses such as xyloglucan, mannan and xylan. DMP-AF contained a pectic polysaccharide mainly consisting of an unusually long homogalacturonan backbone. Enzymatic treatment by pectinase of DMP-AF yielded DMP-ED, which contained a rhamnogalacturonan-I backbone with arabinan, galactan and arabinogalactan side chains. Both DMP-NF and DMP-ED induced IFN-γ and TNF-α secretion in peripheral blood mononuclear cells (PBMCs), DMP-ED being the most potent fraction. DMP-AF was less active, which might be due to a less sterically available rhamnogalacturonan-I domain.

Lipopolysaccharides from a Shiraia fruiting body-associated bacterium elicit host fungal hypocrellin A biosynthesis through nitric oxide generation

Hypocrellin A (HA) is an excellent perylenequinone photosensitizer from Shiraia fruiting bodies. A dominant bacterium Pseudomonas fulva SB1 in the fruiting body was found to promote HA biosynthesis. The bacterial LPS were purified and the O-specific polysaccharide (OPS) consisted of rhamnose (Rha), galactose (Gal) and N-acetyl-galactosamine (GalNAc) with an average molecular weight of 282.8 kDa. Although the OPS composing of Rhap and Galp backbone showed elicitation capability on fungal HA accumulation, the highest HA production (303.76 mg/L) was achieved by LPS treatment at 20 μg/mL on day 3 of the mycelium culture. The generation of nitric oxide (NO) in Shiraia mycelia was triggered by LPS, which was partially blocked by inhibitors of nitric oxide synthase (NOS) and nitrate reductase (NR), leading to the depressed HA production. Transcriptome analysis revealed that NO mediated LPS-induced HA production via upregulating the expressions of critical genes associated with central carbon metabolism and downstream HA biosynthesis genes. This is the first report of LPS-induced NO to regulate fungal secondary metabolite production, which provides new insights on the role of bacterial LPS in bacterium-fungus interactions and an effective strategy to enhance hypocrellin production.

Isolation, structural characterization, and bioactivities of neutral polysaccharides from Zizania latifolia

The swollen culm (also known as Jiaobai) of Zizania latifolia is formed by the smut Ustilago esculenta invades the Z. latifolia. The new tissue formed due to the symbiotic relationship has entices the attention of researchers to study its polysaccharide structure along with biological evaluation. Five fractions of polysaccharides were obtained owing to hot water extraction, alcoholic precipitation, and chromatographic purification. Bioactivity assays showed that ZLPs have good antioxidant, hypoglycemic activities and protective activity against oxidative damage. The ZLP-1 and ZLP-2 were determined to be neutral polysaccharides with high purity, exhibiting propitious bioactivity, consequently they were subjected to indispensable structural characterization. These results showed that ZLP-1 has molecular weight (Mw) of 103 kDa and glucose (Glc) (76.68 %) as the primary monosaccharide; the ZLP-2 has Mw of 122 kDa and galactose (Gal) (41.04 %) and arabinose (Ara) (27.12 %). Structural elucidation by methylation and nuclear magnetic resonance (NMR) analysis suggested ZLP-1 is a glucan, with →3)-β-Glcp-(1→3)-β-Glcp-(1→4)-β-Glcp-(1→4)-β-Glcp-(1→3,6)-β-Galp-(1→3)-β-Glcp-(1→ as the mainchain and the terminal Araf and Glcp; the ZLP-2 is a Galactoxylan, with →3,4)-β-xylp-(1→3)-β-Galp-(1→3,6)-β-Galp-(1→3,6)-β-Galp-(1→ as the mainchain and the terminal Araf and Glcp. The structural arrangements provide a chemical basis for understanding the nutritional and pharmacological activities of polysaccharides from Zizania latifolia.

Isolation, characterization, trypsin inhibition, liver protective and antioxidant activities of arabinoxylan from Massa Medicata Fermentata and its processed products

Massa Medicata Fermentata (MMF) is a traditional Chinese medicine widely used in feed additives and human medicine. In this study, two neutral polysaccharides (SMMFP-1 and CMMFP-1) were isolated from two forms of MMF (sheng and chao MMF), and their structural characteristics and bioactivities were studied. The results showed that CMMFP-1 had higher average Mw compared with that of SMMFP-1. SMMFP-1 had a lower proportion of Ara, Xyl, GalA, and GlcA, but higher levels of Fuc, Gal, Man, and GulA. Compared with CMMFP-1, SMMFP-1 had a triple helix structure. SMMFP-1 had a layered structure, whereas CMMFP-1 had a curly layered structure. More glycosidic linkage types were found in SMMFP-1 than in CMMFP-1, and SMMFP-1 had a greater number of side chains. More importantly, SMMFP-1 showed better trypsin inhibition activity in vitro, liver-protective activity in vivo, and stronger antioxidant activity in vivo than CMMFP-1. Thus, arabinoxylans may be one of the active substances for different efficacies between MMF and its processed product. The results of this study facilitate the exploration of the correlation between the structural characteristics and biological functionalities of MMF arabinoxylans. Moreover, a theoretical basis is established for further study of the unique properties of arabinoxylans and their applications.

Ficus carica polysaccharide extraction via ultrasound-assisted technique: Structure characterization, antioxidant, hypoglycemic and immunomodulatory activities

In this research, the ultrasound-assisted extraction (UAE) conditions of the water-soluble polysaccharide (FCPS) from Ficus carica fruits were optimized using the response surface methodology. The optimal FCPS yield was 7.97 % achieved by conducting ultrasound-assisted extraction four times at a solid-liquid ratio of 1:20 (g/mL) and an ultrasound temperature of 70 °C. Then, the structure, antioxidant properties, hypoglycemic effects, and immunomodulatory activities of FCPS were evaluated. FCPS was characterized as irregular, rough-surfaced, flaky materials consisting of pyran-type polysaccharides with α- and β-glycosidic linkages, and composed of multiple monosaccharides and only one homogeneous concentrated polysaccharide component (FCPS1) with a molecular weight of 4.224 × 104 Da. The results suggested FCPS exhibited remarkable antioxidant activity in vitro, as evidenced by improved cell viability and reduced the reactive oxygen species (ROS) levels. Meanwhile, FCPS effectively improved liver-related insulin resistance by promoting glucose consumption in hepatocytes and activated the immune response through activation of murine bone marrow-derived dendritic cells (DCs) and upregulation of interleukin 6 (IL6) and interleukin 12 (IL-12) expression. The findings demonstrate the efficacy of the UAE technique in isolating FCPS with biological functionality and FCPS could potentially serve as a beneficial organic antioxidant source and functional food, carrying important implications for future studies.

Ultrasound-assisted extraction and characterization of Penthorum chinense polysaccharide with anti-inflammatory effects

Penthorum chinense has been used in both food and medication for many years, and polysaccharide of which was considered as one of the bioactive compounds. However, the extraction process of polysaccharide from P. chinense (PCP) was not well optimized. Ultrasound-assisted extractionhas been widely employed in the extraction of natural products for its compliance with the concept of green and economic chemistry. To better investigate the structure and biology activity of PCP, response surface methodology was employed to optimize the ultrasound-assisted extraction conditions of PCP. The optimum extraction for the ultrasound-assisted extraction of PCP were obtained as ratio of solvent to material 40 mL/g, ultrasonic power 380 W, and extraction time of 50 min. The yield of PCP reached 8.71% under these optimized conditions. PCP was further purified by using anion exchange chromatography and gel filtration, an acidic fraction PCP-AP-1 was hereby obtained. The results of structural elucidation indicated that PCP-AP-1 was a typical pectic polysaccharide with a molecular weight of 66360 Da, mainly composed of galacturonic acid (68.5 mol%), followed by arabinose (9.8 mol%), rhamnose (9.4 mol%), glucose (7.7 mol%), with homogalacturonan region and rhamnogalacturonan I regions. In vitro study showed that PCP-AP-1 could improve the inflammation induced by lipopolysaccharide in intestinal epithelial cells, which was probably performed through the inhibition of multiple signaling pathways including the inhibition of TLR4, NOD1/2 and NF-κB pathway, as well as the reduction of NLRP3 inflammasome. This study defined the type of polysaccharide present in P. chinense and revealed a potential of application this plant in the prevention of intestinal inflammatory diseases.

Structure-activity relationship of low molecular weight Astragalus membranaceus polysaccharides produced by Bacteroides

Astragalus membranaceus polysaccharides (APS) possess significant biological activities, such as anti-tumor, antiviral, and immunomodulatory activities. However, there is still a lack of research on the structure-activity relationship of APS. In this paper, two carbohydrate-active enzymes from Bacteroides in living organisms were used to prepare degradation products. The degradation products were divided into APS-A1, APS-G1, APS-G2, and APS-G3 according to molecular weight. Structural analysis showed that all degradation products had an α-1,4-linked glucose backbone, but APS-A1 and APS-G3 also had branched chains of α-1,6-linked galactose or arabinogalacto-oligosaccharide. In vitro, immunomodulatory activity evaluation results indicated that APS-A1 and APS-G3 had better immunomodulatory activity, while the immunomodulatory activities of APS-G1 and APS-G2 were comparatively weaker. Molecular interaction detection showed that APS-A1 and APS-G3 could bind to toll-like receptors-4 (TLR-4) with a binding constant of 4.6 × 10^-5 and 9.4 × 10^-6, respectively, while APS-G1 and APS-G2 failed to bind to TLR-4. Therefore, the branched chains of galactose or arabinogalacto-oligosaccharide played a crucial role in the immunomodulatory activity of APS.

Polysaccharides and Bioactive Phenolics from Aconitum septentrionale Roots

Aconitum septentrionale is known to contain toxic diterpene alkaloids, while other bioactive compounds in the plant remain unclear. The aim of this study was to explore the phenolic compounds and polysaccharides from the water extract of A. septentrionale roots. Fifteen phenolic compounds were isolated and identified by NMR and MS, including fourteen known and one new dianthramide glucoside (2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-4,5-dihydroxybenzoic acid methyl ester, 14). One neutral (complex of glucans with minor amounts of mannans) and two acidic polysaccharide fractions (complexes of pectic polysaccharides and glucans) were also obtained. Hydroxytyrosol (1), hydroxytyrosol-1-O-β-glucoside (2) and bracteanolide A (7) inhibited the release of nitric oxide by dendritic cells. Magnoflorine (8) and 2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-5-hydroxybenzoic acid methyl ester (12) inhibited 15-lipoxygenase, and bracteanolide A (7) was a moderate inhibitor of xanthine oxidase. This study is the first to describe the diversity of phenolics and polysaccharides from A. septentrionale and their anti-inflammatory and anti-oxidant activities.

A review on efforts for improvement in medicinally important chemical constituents inAconitum through biotechnological interventions

The genus Aconitum belongs to the family Ranunculaceae, is endowed with more than 350 species on the earth. Medicinally important aconitine type of diterpenoid alkaloids are the characteristic compounds in most of the Aconitum species. The present review endeavored the major research carried out in the field of genetic resource characterization, pharmacological properties, phytochemistry, major factors influencing quantity, biosynthetic pathways and processing methods for recovery of active ingredients, variety improvement, propagation methods, and important metabolite production through cell/organ culture of various Aconitum species. More than 450 derivatives of aconitine-type C19 and C20-diterpenoid alkaloids along with a few other non-alkaloidal compounds, such as phenylpropanoids, flavonoids, terpenoids, and fatty acids, have been identified in the genus. A few Aconitum species and their common diterpenoid alkaloid compounds are also well characterized for analgesic, inflammatory and cytotoxic properties. However, the different isolated compound needs to be validated for supporting other traditional therapeutical uses of the plant species. Aconitine alkaloids shared common biosynthesis pathway, but their diversification mechanism remains unexplored in the genus. Furthermore, the process needs to be developed on secondary metabolite recovery, mass-scale propagation methods, and agro-technologies for maintaining the quality of products. Many species are losing their existence in nature due to over-exploitation or anthropogenic factors; thus, temporal monitoring of the population status in its habitat, and suitable management programs for ascertaining conservation needs to be developed.

Beyond cellulose: pharmaceutical potential for bioactive plant polysaccharides in treating disease and gut dysbiosis

Polysaccharides derived from plants, algae, or fungi serve as the major components of some human diets. Polysaccharides have been shown to exhibit diverse biological activities in improving human health, and have also been proposed to function as potent modulators of gut microbiota composition, thus playing a bi-directional regulatory role in host health. Here, we review a variety of polysaccharide structures potentially linked to biological functions, and cover current research progress in characterizing their pharmaceutical effects in various disease models, including antioxidant, anticoagulant, anti-inflammatory, immunomodulatory, hypoglycemic, and antimicrobial activities. We also highlight the effects of polysaccharides on modulating gut microbiota via enrichment for beneficial taxa and suppression of potential pathogens, leading to increased microbial expression of carbohydrate-active enzymes and enhanced short chain fatty acid production. This review also discusses polysaccharide-mediated improvements in gut function by influencing interleukin and hormone secretion in host intestinal epithelial cells.

Rhopilema esculentum polysaccharides enhance epithelial cell barrier in vitro and alleviate chronic colitis in mice

The purposes of this study were to characterize polysaccharides from Rhopilema esculentum and to explore their impacts on gut barrier function and inflammation in vitro and in mice with chronic colitis triggered by long-term administration of dextran sulfate sodium (DSS). Two polysaccharides were isolated and purified from Rhopilema esculentum, named REP-1 and REP-2. REP-1 with a molecular weight of 8.21 kDa was composed of mannose, glucosamine, galactosamine, glucose, galactose, and arabinose with a molar ratio of 0.04:0.03:0.38:1:1.36:0.06, and REP-2 with a molecular weight of 10.11 kDa mainly consisted of mannose, glucuronic acid, galactosamine, glucose, galactose, and arabinose with a molar ratio of 0.04:0.12:0.41:1:1.2:0.06. Compared to REP-1, REP-2 displayed better ability to up-regulate the expression of genes related to tight junctions and mucus in LPS-stimulated Caco-2 cells and better immunomodulatory activities in RAW264.7 macrophages. Then mice experiments showed that REP-2 efficiently attenuated the symptoms of colitis, decreased the secretion of pro-inflammatory cytokines, and restored intestinal barrier function in mice with chronic colitis. These results demonstrate that REP-2 might be a promising agent for protecting intestinal and mucus barrier and mitigating inflammation-associated intestinal diseases such as ulcerative colitis.

Structure and potential anti-fatigue mechanism of polysaccharides from Bupleurum chinense DC

Two polysaccharides, BCP-1 and BCP-2, were obtained from Bupleurum chinense DC. by water extraction and ultrafiltration. BCP-1 (1.04 × 10⁵ Da) and BCP-2 (2.14 × 10⁴ Da) were composed of Mannose, Rhamnose, Glucose, Galactose, Arabinose, and Galacturonic acid in different proportions. They both contained oligogalacturonides in their main chain. Besides, the backbone of BCP-1 was composed of 4-β-Galp and 4,6-β-Glcp, and branched at C4 of 4,6-β-Glcp. While BCP-2 contained a backbone of 3,5-α-Araf residues with branches at C3. BCP-2 effectively extended the forced swimming time, improved the glycogen reserves and antioxidant system, decreased the levels of blood urea nitrogen, lactic acid, lactate dehydrogenase and creatinine kinase expression. It alleviated physical fatigue through regulating 5'-AMP-activated protein kinase (AMPK) and Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) signalling pathway in skeletal muscles. This study demonstrated that BCP-2 exhibited more effective anti-fatigue activity than BCP-1 potentially associated with its primary and higher structures.

Diverse alkaloids from the aerial parts of Aconitum carmichaelii and antiproliferative activity of costemline via inhibiting SIRT1/ROCK1/P-STAT3 pathways

Six undescribed alkaloids together with 15 known alkaloids were isolated from the aerial parts of Aconitum carmichaelii. Their structures were elucidated extensively by NMR and HRESIMS spectroscopy. The absolute configurations of N-formyllaurotetanine, and the known compounds glaucine-β-N-oxide and glaucine-α-N-oxide were established by electronic circular dichroism (ECD) spectra. Notably, it was the discovery of rare indole alkaloids from the genus Aconitum, and biosynthetic pathway of compounds 1 and 6 was deduced. Evaluation of the antiproliferative activity of these alkaloids demonstrated that costemline exhibited significant anti-proliferation effects against HCT116, SKOV3, and A549 cells with IC₅₀ values of 5.6, 14.2, and 6.8 μM, respectively. Costemline could also inhibit the cell invasion activity of HCT116 cells. Mechanistic studies in HCT116 cells suggested that the antiproliferative activity of costemline was attributable to SIRT1/ROCK1/P-STAT3 pathways regulation. This study revealed the potential for developing and utilizing the aerial parts of Aconitum carmichaelii.

Preparation, structural characterization, antioxidant activity and protection against cisplatin-induced acute kidney injury by polysaccharides from the lateral root of Aconitum carmichaelii

Response surface methodology (RSM) and Box- Behnken design (BBD) based on one-way experiments were used to optimize the extraction parameters of the lateral root polysaccharides of Aconitum carmichaelii. The extracted polysaccharides were named as refined fucose polysaccharide. The optimal conditions included a water to raw material ratio of 43, an extraction time of 2 h, and an extraction temperature of 90°C. The shape of RFP was shown by infrared spectroscopy (IR) and scanning electron microscopy (SEM) analysis. The monosaccharide composition and molecular weight of RFP was determined by high-performance liquid chromatography (HPLC). Furthermore, RFP exhibited moderate antioxidant activity by analyzing the scavenging rates of 2,2-diphenyl-1-picrylhydrazyl radical, superoxide anion radical, hydroxyl radical, and ABTS + radical. RFP exerted cytoprotective effects against hydrogen peroxide (H2O2)-induced injury in the rat renal tubular epithelial cell line rat renal tubular epithelial cells (NRK-52E) and inhibited apoptosis. In addition, researches found that RFP could alleviate cisplatin-induced acute kidney injury in mice by enhancing the levels of glutathione (GSH) and glutathione peroxidase-4 (GPX-4), decreasing the levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), reducing lipid peroxidation, and thus inhibiting ferroptosis. In conclusion, this study provides a good strategy for obtaining bioactive polysaccharides from Fuzi.