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.

Isolation, characterisation and complement fixation activity of acidic polysaccharides from Argemone mexicana used as antimalarials in Mali.

CONTEXT: Global studies on Argemone mexicana L. (Papaveraceae) traditionally used against malaria in Mali are limited to its low-mass compounds activities, and little information on its bioactive polysaccharides is available. OBJECTIVE: This study determines the structure and the immunomodulatory activity of polysaccharides from aerial parts of A. mexicana. MATERIALS AND METHODS: Acidic polysaccharides from this plant material named HMAmA1 and HMAmA2 were isolated from water extracts. Their monosaccharide composition was determined by gas chromatography. Glycosidic linkages were determined using GC-MS. NMR was also applied. The polymers were tested for effects on the human complement system in vitro at different doses. RESULTS: The monosaccharide composition showed that the two polysaccharides contained in different amounts the following monomers: arabinose, rhamnose, galactose, and galacturonic acid. Overall structural analysis showed the presence of a low ratio of 1,2-linked rhamnose compared to 1,4-linked galacturonic acid with arabinogalactans substituted on position 4 of rhamnose. NMR data showed the presence of galacturonans alternated by rhamnogalacturonans bearing arabinose and galactose units. α-Linkages were found for l-arabinose, l-rhamnose and d-galacturonic acid, while ß-linkages were found for d-galactose. The two polysaccharides exhibited strong complement fixation activities, with HMAmA1 being the highest potent fraction. ICH50 value of HMAmA1 was 5 µg/mL, compared to the control BPII being 15.9 µg/mL. DISCUSSION AND CONCLUSIONS: Polysaccharides form A. mexicana presented a complement fixation effect. The complement system is an important part of the immune defense, and compounds acting on the cascade are of interest. Therefore, these polymers may be useful as immunodulatory agents.

A Polysaccharide Isolated from Codonopsis pilosula with Immunomodulation Effects Both In Vitro and In Vivo.

In this study, an acidic polysaccharide from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (WCP-I) and its main fragment, WCP-Ia, obtained after pectinase digestion, were structurally elucidated and found to consist of a rhamnogalacturonan I (RG-I) region containing both arabinogalactan type I (AG-I) and type II (AG-II) as sidechains. They both expressed immunomodulating activity against Peyer's patch cells. Endo-1,4-ß-galactanase degradation gave a decrease of interleukine 6 (IL-6) production compared with native WCP-I and WCP-Ia, but exo-α-l-arabinofuranosidase digestion showed no changes in activity. This demonstrated that the stimulation activity partly disappeared with removal of ß-d-(1→4)-galactan chains, proving that the AG-I side chain plays an important role in immunoregulation activity. WCP-Ia had a better promotion effect than WCP-I in vivo, shown through an increased spleen index, higher concentrations of IL-6, transforming growth factor-ß (TGF-ß), and tumor necrosis factor-α (TNF-α) in serum, and a slight increment in the secretory immunoglobulin A (sIgA) and CD4+/CD8+ T lymphocyte ratio. These results suggest that ß-d-(1→4)-galactan-containing chains in WCP-I play an essential role in the expression of immunomodulating activity. Combining all the results in this and previous studies, the intestinal immune system might be the target site of WCP-Ia.

Characterization of Inulin-Type Fructan from Platycodon grandiflorus and Study on Its Prebiotic and Immunomodulating Activity.

Platycodon grandiflorus is a plant widely used in traditional Chinese medicine, of which polysaccharides are reported to be the main components responsible for its bio-functions. In this work, the inulin-type fructan (PGF) was obtained by DEAE anion exchange chromatography from the water extracted from P. grandifloras. Characterization was performed with methanolysis, methylation, and NMR and the results showed that PGF is a ß-(2-1) linked fructan, with terminal glucose and with a degree of polymerization of 2⁻10. In order to study its biofunctions, the prebiotic and immunomodulation properties were assayed. We found that PGF exhibited good prebiotic activity, as shown by a promotion on six strains of lactobacillus proliferation. Additionally, the PGF also displayed direct immunomodulation on intestinal epithelial cells and stimulated the expressions of anti-inflammatory factors. These results indicated that the inulin from P. grandiflorus is a potential natural source of prebiotics as well as a potential intestinal immunomodulator, which will be valuable for further studies and new applications.

Purification and Partial Structural Characterization of a Complement Fixating Polysaccharide from Rhizomes of Ligusticum chuanxiong.

Rhizome of Ligusticum chuanxiong is an effective medical plant, which has been extensively applied for centuries in migraine and cardiovascular diseases treatment in China. Polysaccharides from this plant have been shown to have interesting bioactivities, but previous studies have only been performed on the neutral polysaccharides. In this study, LCP-I-I, a pectic polysaccharide fraction, was obtained from the 100 °C water extracts of L. chuangxiong rhizomes and purified by diethylaminethyl (DEAE) sepharose anion exchange chromatography and gel filtration. Monosaccharide analysis and linkage determination in addition to Fourier transform infrared (FT-IR) spectrometer and Nuclear magnetic resonance (NMR) spectrum, indicated that LCP-I-I is a typical pectic polysaccharide, with homo-galacturonan and rhamnogalacturonan type I regions and arabinogalactan type I and type II (AG-I/AG-II) side chains. LCP-I-I exhibited potent complement fixation activity, ICH50 of 26.3 ± 2.2 µg/mL, and thus has potential as a natural immunomodulator.

Genetic and molecular analyses reveal an evolutionary trajectory for glycan synthesis in a bacterial protein glycosylation system.

Although protein glycosylation systems are becoming widely recognized in bacteria, little is known about the mechanisms and evolutionary forces shaping glycan composition. Species within the genus Neisseria display remarkable glycoform variability associated with their O-linked protein glycosylation (pgl) systems and provide a well developed model system to study these phenomena. By examining the potential influence of two ORFs linked to the core pgl gene locus, we discovered that one of these, previously designated as pglH, encodes a glucosyltransferase that generates unique disaccharide products by using polyprenyl diphosphate-linked monosaccharide substrates. By defining the function of PglH in the glycosylation pathway, we identified a metabolic conflict related to competition for a shared substrate between the opposing glycosyltransferases PglA and PglH. Accordingly, we propose that the presence of a stereotypic, conserved deletion mutation inactivating pglH in strains of Neisseria gonorrhoeae, Neisseria meningitidis, and related commensals, reflects a resolution of this conflict with the consequence of reduced glycan diversity. This model of genetic détente is supported by the characterization of pglH "missense" alleles encoding proteins devoid of activity or reduced in activity such that they cannot exert their effect in the presence of PglA. Thus, glucose-containing glycans appear to be a trait undergoing regression at the genus level. Together, these findings document a role for intrinsic genetic interactions in shaping glycan evolution in protein glycosylation systems.

Complement fixing polysaccharides from Terminalia macroptera root bark, stem bark and leaves.

The root bark, stem bark and leaves of Terminalia macroptera were sequentially extracted with ethanol, 50% ethanol-water, and 50 °C and 100 °C water using an accelerated solvent extractor. Ten bioactive purified polysaccharide fractions were obtained from those crude extracts after anion exchange chromatography and gel filtration. The polysaccharides and their native extracts were characterized with respect to molecular weight, chemical compositions and effects in the complement assay. The chemical compositions showed that the polysaccharides are of pectic nature. The results indicated that there was no great difference of the complement fixation activities in the crude extracts from the different plant parts when extracting with the accelerated solvent extraction system. The purified polysaccharide fractions 100WTSBH-I-I and 100WTRBH-I-I isolated from the 100 °C water extracts of stem and root bark respectively, showed the highest complement fixation activities. These two fractions have rhamnogalacturonan type I backbone, but only 100WTSBH-I-I contains side chains of both arabinogalactan type I and II. Based on the yield and activities of the fractions studied those from the root bark gave highest results, followed by those from leaves and stem bark. But in total, all plant materials are good sources for fractions containing bioactive polysaccharides.

α-Glucosidase inhibition, 15-lipoxygenase inhibition, and brine shrimp toxicity of extracts and isolated compounds from Terminalia macroptera leaves.

CONTEXT: Terminalia macroptera Guill. & Perr. (Combretaceae), a tree that grows in West Africa, has been used in traditional medicine against a variety of diseases such as hepatitis, gonorrhea, skin diseases, and diabetes. OBJECTIVE: To investigate enzyme inhibitory activity against α-glucosidase and 15-lipoxygenase (15-LO) and toxicity against brine shrimp of extracts and compounds from T. macroptera leaves. MATERIALS AND METHODS: Methanol extract, ethyl acetate, and butanol extracts obtained from the methanol extract, six isolated polyphenols (chebulagic acid, chebulic acid trimethyl ester, corilagin, methyl gallate, narcissin, and rutin), and shikimic acid were evaluated for enzyme inhibition and toxicity. RESULTS: In enzyme inhibition assays, all extracts showed high or very high activity. Chebulagic acid showed an IC50 value of 0.05 µM towards α-glucosidase and 24.9 ± 0.4 µM towards 15-LO, in contrast to positive controls (acarbose: IC50 201 ± 28 µM towards α-glucosidase, quercetin: 93 ± 3 µM towards 15-LO). Corilagin and narcissin were good 15-LO and α-glucosidase inhibitors, as well, while shikimic acid, methyl gallate, and chebulic acid trimethyl ester were less active or inactive. Rutin was a good α-glucosidase inhibitor (IC50 ca. 3 µM), but less active towards 15-LO. None of the extracts or the isolated compounds seemed to be very toxic in the brine shrimp assay compared with the positive control podophyllotoxin. CONCLUSION: Inhibition of α-glucosidase in the gastrointestinal tract may be a rationale for the medicinal use of T. macroptera leaves against diabetes in traditional medicine in Mali. The plant extracts and its constituents show strong inhibition of the peroxidative enzyme 15-LO.

Polyherbal Combinations Used by Traditional Health Practitioners against Mental Illnesses in Bamako, Mali, West Africa.

This study explores the traditional knowledge of plants used by traditional health practitioners (THPs) in the treatment of symptoms or syndromes related to mental illnesses in the district of Bamako in Mali, along with the identification of affiliated traditional treating methods. An exploratory and cross-sectional ethnopharmacological survey was conducted in the district of Bamako. The Malian Federation of Associations of Therapists and Herbalists (FEMATH) assisted in the identification and inclusion of the THPs. Data sampling included semi-structured interviews, questionnaires, and in-depth interviews. Quantitative data were evaluated by analysing reports of the use of different medicinal plants and the number of participants. Fifteen THPs belonging to the district of Bamako participated. In total, 43 medicinal plants belonging to 22 plant families were used by the THPs. The most cited plant species was Securidaca longepedunculata (violet tree), followed by Khaya senegalensis (African mahogany) and Boscia integrifolia (rough-leaved shepherds tree). A great number of herbal combinations, preparation methods, and administration routes were used, often with honey as an adjuvant. To our knowledge, this is the first ethnobotanical survey on the use of medicinal plants in the treatment of all types of mental disorders in Bamako.

Salvia miltiorrhiza polysaccharide and its related metabolite 5-methoxyindole-3-carboxaldehyde ameliorate experimental colitis by regulating Nrf2/Keap1 signaling pathway.

The roots of Salvia miltiorrhiza have been used in Traditional Chinese Medicine for thousands of years. However, tons of aerial parts of this plant are usually discarded in the production of roots preparation. To make better use of these plant resources, the polysaccharide isolated from the aerial part of S. miltiorrhiza was investigated for its potential protection against intestinal diseases. A pectic polysaccharide (SMAP-1) was isolated and characterized being composed of homogalacturonan as the main chain and rhamnogalacturonan type I as ramified region, with side chains including arabinans and possible arabinogalactan type I and II. SMAP-1 exhibited robust protective effects against dextran sodium sulfate (DSS)-induced colitis and restored colitis symptoms, colonic inflammation, and barrier functions. Anti-oxidative effects were also observed by up-regulating Nrf2/Keap1 signaling pathway. Additionally, the level of serum 5-methoxyindole-3-carboxaldehyde (5-MC) was restored by SMAP-1 identified in metabolomic analysis, being correlated with the aforementioned effects. Protection against oxidative stress on intestinal porcine enterocyte cells (IPEC-J2) by 5-MC was observed through the activation of Nrf2/Keap1 system, as also shown by SMAP-1. In conclusion, SMAP-1 could be a promising candidate for colitis prevention, and 5-MC could be the signal metabolite of SMAP-1 in protecting against oxidative stress in the intestine.

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

Roots of Aconitum carmichaelii are used in Asian countries due to its content of bioactive alkaloids. In the production of root preparations, tons of leaves are usually discarded, leading to a huge waste of herbal material. The aim of this study is to investigate the polysaccharides in these unutilized leaves. A neutral polysaccharide (AL-N) appeared to be a mixture of heteromannans, and two purified acidic polysaccharides (AL-I-I and AL-I-II) were shown to be pectins containing a homogalacturonan backbone substituted with terminal ß-Xylp-units. AL-I-I consisted of a type-I rhamnogalacturonan core, with arabinan and type-II arabinogalactan domains while AL-I-II was less branched. AL-N and AL-I-I were able to modulate the complement system, while AL-I-II was inactive. Interestingly, AL-N, AL-I-I and AL-I-II were shown to exert anti-inflammatory effects on porcine enterocyte IPEC-J2 cells. AL-I-I and AL-I-II were able to down-regulate the expression of toll-like receptor 4 (TLR4) and nucleotide-binding oligomerization domain 1 (NOD1).

Benefits of neutral polysaccharide from rhizomes of Polygonatum sibiricum to intestinal function of aged mice.

One purified neutral polysaccharide fraction was obtained from the rhizome of Polygonatum sibiricum by DEAE ion exchange and gel chromatography. Structure elucidation was performed by methanolysis, methylation, FT-IR, and NMR. The results indicated that PSP-NP was composed of 1,4-ß-D-Gal,1, 4, 6-ß-D-Gal, T-α-D-Man,1, 4-α-D-Glc, and T-α-D-Glc with a molecular weight of 43.0 kDa. We supplied this polysaccharide to aged mice and found it is of benefits to intestinal functions, as indicated by better tissue integrity and motility, improved oxidative stress and inflammation, reduced intestinal permeability and serum LPS level, as well as balanced gut microbial composition and short-chain fatty acids production. These results display a novel Polygonatum sibiricum polysaccharide to improve the intestinal function of aged mice, which provides pieces of evidence for its further development and utilization.

Structural Features and Immunomodulatory Effects of Water-Extractable Polysaccharides from Macrolepiota procera (Scop.) Singer.

Macrolepiota procera (MP) is an edible mushroom used in the treatment of diabetes, hypertension and inflammation. However, the structure and biological effects of its polysaccharides (PSs) are unclear. This study investigates the structural features of a PS complex from MP (MP-PSC), its immunomodulatory activities and effects on probiotic and pathogenic bacteria. MP-PSC was obtained by boiling water, and PSs were characterized by 2D NMR spectroscopy. The immunomodulatory effects on blood and derived neutrophils, other leukocytes, and murine macrophages were studied by flow cytometry, chemiluminescence, spectrophotometry, and ELISA. The total carbohydrate content of MP-PSC was 74.2%, with glycogen occupying 36.7%, followed by ß-D-glucan, α-L-fuco-2-(1,6)-D-galactan, and ß-D-glucomannan. MP-PSC (200 µg/mL) increased the number of CD14+ monocyte cells in the blood, after ex vivo incubation for 24 h. It dose-dependently (50-200 µg/mL) activated the spontaneous oxidative burst of whole blood phagocytes, NO, and interleukin 6 productions in RAW264.7 cells. MP-PSC exhibited a low antioxidant activity and failed to suppress the oxidative burst and NO generation, induced by inflammatory agents. It (2.0%, w/v) stimulated probiotic co-cultures and hindered the growth and biofilm development of Escherichia coli, Streptococcus mutans and Salmonella enterica. MP PSs can be included in synbiotics to test their immunostimulating effects on compromised immune systems and gut health.

Structural features and antioxidant activities of polysaccharides from different parts of Codonopsis pilosula var. modesta (Nannf.) L. T. Shen.

In this study, three acidic polysaccharides from different plant parts of Codonopsis pilosula var. Modesta (Nannf.) L. T. Shen were obtained by ion exchange chromatography and gel filtration chromatography, and the yields of these three polysaccharides were different. According to the preliminary experimental results, the antioxidant activities of the polysaccharides from rhizomes and fibrous roots (CLFP-1) were poor, and was thus not studied further. Due to this the structural features of polysaccharides from roots (CLRP-1) and aerial parts (CLSP-1) were the object for this study and were structurally characterized, and their antioxidant activities were evaluated. As revealed by the results, the molecular weight of CLRP-1and CLSP-1 were 15.9 kDa and 26.4 kDa, respectively. The monosaccharide composition of CLRP-1 was Ara, Rha, Fuc, Xyl, Man, Gal, GlcA, GalA in a ratio of 3.8: 8.4: 1.0: 0.8: 2.4: 7.4: 7.5: 2.0: 66.7, and Ara, Rha, Gal, GalA in a ratio of 5.8: 8.9: 8.0: 77.0 in for CLSP-1. The results of structural elucidation indicated that both CLRP-1 and CLSP-1 were pectic polysaccharides, mainly composed of 1, 4-linked galacturonic acid with long homogalacturonan regions. Arabinogalactan type I and arabinogalactan type II were presented as side chains. The antioxidant assay in IPEC-J2 cells showed that both CLRP-1 and CLSP-1 promoted cell viability and antioxidant activity, which significantly increase the level of total antioxidant capacity and the activity of superoxide dismutase, catalase, and decrease the content of malondialdehyde. Moreover, CLRP-1 and CLSP-1 also showed powerful antioxidant abilities in Caenorhabditis elegans and might regulate the nuclear localization of DAF-16 transcription factor, induced antioxidant enzymes activities, and further reduced reactive oxygen species and malondialdehyde contents to increase the antioxidant ability of Caenorhabditis elegans. Thus, these finding suggest that CLRP-1 and CLSP-1 could be used as potential antioxidants.

A novel serine protease from pseuderanthemum latifolium B. Hansen: Characterization and fibrino(geno)lytic activities.

Protease (PPL) was isolated from Pseuderanthemum latifolium B. Hansen and had a molecular mass of 70 kDa. The N-terminal sequence of PPL showed 70-80% similarity with of subtilisin-like serine proteases from plants, but it did not show any sequence homology with known plant proteases. Serine protease inhibitors (PMSF, DFP) effectively blocked about 90% of PPL activity. PPL was highly activity at the pH range from 6 to 9 and temperatures from 50 °C to 80 °C, with an optimum at pH 7.0 and temperatures 70 °C. PPL had stability in a variety of pH, temperature, surfactant and oxidizing agents. PPL with concentration of 2.5 µg completely hydrolyzed the Aα-chain of fibrinogen within 5 min and hydrolyzed the Bß and the γ-chain after 10 h. Fibrin also was strong hydrolyzed by PPL with concentration of 0.3 µg. Thus, PPL is a unique serine protease, which it had strong fibrino(geno)lytic activities.

Pectic polysaccharide from Nelumbo nucifera leaves promotes intestinal antioxidant defense in vitro and in vivo.

In this study, the Nelumbo nucifera leaf polysaccharide (NNLP) was isolated by hot water extraction and ethanol precipitation. DEAE anion exchange chromatography and gel filtration were further performed to obtained the purified fraction NNLP-I-I, the molecular weight of which was 16.4 kDa. The monosaccharide composition analysis and linkage units determination showed that the fraction NNLP-I-I was a pectic polysaccharide. In addition, the NMR spectra analysis revealed that NNLP-I-I mainly consisted of a homogalacturonan backbone and rhamnogalacturonan I, containing a long HG region and short RG-I region, with AG-II and 1-3 linked rhamnose as side chains. The biological studies demonstrated that NNLP-I-I displayed antioxidant properties through mediating the Nrf2-regulated intestinal cellular antioxidant defense, which could protect cultured intestinal cells from oxidative stress and improve the intestinal function of aged mice.

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.

Bioactive arabinogalactans from the leaves of Opilia celtidifolia Endl. ex Walp. (Opiliaceae).

The leaves of the tree Opilia celtidifolia have a long tradition for being used in Mali and other West African countries against various ailments such as for wound healing. Previous studies on polysaccharides from these leaves showed the presence of pectic-like polymers with an effect on the human complement system as well as the ability to activate macrophages. The present study shows that bioactive arabinogalactans isolated by water of 50°C could be separated into two acidic fractions, Oc50A1 and Oc50A2. The former could, by gel filtration on Sephacryl S-400, be separated into two fractions, which were further purified on a Superdex 200 column to give the fractions Oc50A1.I.pur and Oc50A1.II.pur. These fractions were subjected to chemical and biological studies. The polysaccharides consisted mainly of heavily branched type II arabinogalactans and minor amounts of rhamnogalacturonan I regions. The isolated polymers had a high human complement-fixating ability, as well as the ability to stimulate rat macrophages and dendritic cells (DCs) and to induce B cell proliferation. These effects were especially pronounced for the higher molecular weight fraction of Oc50A1.I.pur. The fractions Oc50A1.I.pur and Oc501.II.pur stimulated secretion of pro-inflammatory cytokines from purified B cells or DCs. Collectively, these results indicate that the arabinogalactan type II polymers present in the leaves of O. celtidifolia may be used to develop medical devices for regulating inflammatory processes.

Structural features of pectic polysaccharides from stems of two species of Radix Codonopsis and their antioxidant activities.

In this study, two pectic polysaccharides from stems of Codonopsis pilosula (CPSP-1) and C. tangshen (CTSP-1) were obtained by ion exchange chromatography and gel filtration. The molecular weight of CPSP-1 and CTSP-1 were 13.1 and 23.0 kDa, respectively. The results of structure elucidation indicated that both CPSP-1 and CTSP-1 are pectic polysaccharides with long homogalacturonan regions (HG) (some of galacturonic acid units were methyl esterified) and rhamnogalacturonan I (RG-I) regions. Side chains for CTSP-1 are both arabinogalactan type I (AG-I) and type II (AG-II), while CPSP-1 only has AG-II. The biological test demonstrated that CPSP-1 and CTSP-1 displayed an antioxidant property through mediating the intestinal cellular antioxidant defense system, which could protect cultured intestinal cells from oxidative stress induced oxidative damages and cell viability suppression. CPSP-1 and CTSP-I showed different bioactivities and mechanisms, which may be due to the difference in their structures.

Neutral Polysaccharide from the Leaves of Pseuderanthemum carruthersii: Presence of 3-O-Methyl Galactose and Anti-Inflammatory Activity in LPS-Stimulated RAW 264.7 Cells.

Pseuderanthemum carruthersii (Seem.) Guillaumin is a native tree in Vietnam. The water extract of the leaves from this tree gives a highly viscous product that has been used to heal wounds and treat inflammations. Our previous studies showed that the leaves of P. carruthersii have a high content of polysaccharides. In this study, the structure and influence of the neutral polysaccharide from Pseuderanthemum carruthersii (PCA1) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were investigated. The PCA1 isolated from P. carruthersii is a galactan-type polysaccharide, containing galactose (77.0%), 3-O-methyl galactose (20.0%), and arabinose (3.0%). Linkage analysis of PCA1 showed that both the 3-O-methyl galactose and galactose were 1,4-linked. The presence of 3-O-methyl galactose units as part of the polysaccharide is important and can be used as a chemotaxonomic marker. The molecular weight of the PCA1 was 170 kDa. A PCA1 concentration of 30-40 µg/mL strongly inhibited TNFα, IL-1ß, and IL-6 inflammatory cytokine production, and reactive oxygen species (ROS) release. PCA1 had inhibitory activities on pro-inflammatory cytokine and ROS release in LPS-stimulated mouse macrophages in vitro through MAPK signaling.