A protein-bound polysaccharide from the stem bark of Eucommia ulmoides and its anti-complementary effect

Advances in Eucommia ulmoides polysaccharides: extraction, purification, structure, bioactivities and applications

Eucommia ulmoides (EU) is a precious tree species native to China originating during the ice age. This species has important economic value and comprehensive development potential, particularly in medicinal applications. The medicinal parts of EU are its bark (Eucommiae cortex) and leaves (Eucommiae folium) which have been successively used as a traditional Chinese medicine to treat diseases since the first century BC. During the last 2 decades, as natural polysaccharides have become of increasing interest in pharmacology, biomedicine, cosmetic and food applications, more and more scholars have begun to study polysaccharides derived from EU as well. EU polysaccharides have been found to have a variety of biological functions both in vivo and in vitro, including immunomodulatory, antioxidant, anti-inflammatory, anticomplementary, antifatigue, and hepatoprotective activities. This review aims to summarize these recent advances in extraction, purification, structural characteristics, pharmacological activities and applications in different fields of EU bark and leaf polysaccharides. It was found that both Eucommiae folium polysaccharides and Eucommiae cortex polysaccharides were suitable for medicinal use. Eucommiae folium may potentially be used to substitute for Eucommiae cortex in terms of immunomodulation and antioxidant activities. This study serves as a valuable reference for improving the comprehensive utilization of EU polysaccharides and further promoting the application of EU polysaccharides.

Preparation techniques, structural features, and bioactivities of Eucommia ulmoides polysaccharides: A review

Eucommia ulmoides Oliv. (tu-chung), as a famous nature medical and edible plant, has the effect of tonifying liver and kidney, strengthening the function of the muscles and bones, and miscarriage prevention. Accumulating evidence has demonstrated that the polysaccharides from Eucommia ulmoides Oliv. (EUPs) are a kind of vital and representative biologically active macromolecules and have various health-promoting biological activities in vivo and in vitro, such as antioxidant activity, immunomodulatory activity, hypolipidemic and hypoglycemic activities, anti-inflammatory activities, anti-tumor activity, and among others. The review aims to comprehensively and systematically collate the recent research progress on extraction and purification methods, structural characteristics, biological activities, mechanism of action, structural modification, and toxicity of EUPs to support their therapeutic potential and health-care functions. New valuable insights for future research with EUPs were also proposed in the areas of structural characterization and pharmacological activities to promoting the development of therapeutic agents and functional foods.

One novel naphthalene derivative and other constituents with anti-complementary activities from the aerial parts of Dracocephalum moldavica

One novel naphthalene derivative, 2-octa-2',4',6'-atriynenaphthalene (1), together with eighteen known compounds (2-19) were isolated from the aerial parts of Dracocephalum moldavica L. Compounds 2, 8, 10, 13, 15-17 and 19 were obtained from the family Lamiaceae for the first time, and compounds 11 and 18 were firstly identified from the genus of Dracocephalum. All the isolates were evaluated for anti-complementary activities through the classical and alternative pathways, and the targets of the most active compounds on the complement activation cascade were also investigated.

Screening of anti-complement active ingredients from Eucommia ulmoides Oliv. branches and their metabolism in vivo based on UHPLC-Q-TOF/MS/MS

Eucommia ulmoides Oliv. (E. ulmoides) is a kind of plant with high medicinal value, there are known as the "gold plants". Some components and contents of barks and branches from E. ulmoides are similar, the barks are mainly used as medicine, but the branches have not been systematically studied and were discarded. In this paper, five fractions extracted from E. ulmoides branches were detected by the classical anti-complement activity assay in vitro. The n-butanol fraction of E. ulmoides branches showed excellent anti-complement activities with a CH₅₀ value of 0.016 ± 0.0014 mg·mL^-1. A total of 76 compounds were identified from the n-butanol fraction, including 9 alkaloids, 18 organic acids, 22 lignans, 15 phenylethanoid glycosides and 12 other compounds. To further prove the anti-complement activity of potential active compounds, those compounds detectable in rat plasma after oral administration were tested by classical anti-complement activity assays. Genipin and pinoresinol 4-O-glucopyranoside had a certain complement inhibitory activity in the 17 potential anti-complements, their CH₅₀ values were 0.050 ± 0.0038 and 0.022 ± 0.0018 mg·mL^-1. UHPLC-Q-TOF/MS/MS was developed to profile and characterize the metabolites of genipin and pinoresinol 4-O-glucopyranoside in rat plasma. Twenty-one and seventeen metabolites were found, respectively. In summary, this study reported important clues for the further pharmacological and clinical studies of E. ulmoides branches. Meanwhile, it provided a practical strategy for rapid screening and identifying of in vivo anti-complement in traditional Chinese medicine.

Structural characterization and anticomplement activity of an acidic polysaccharide containing 3-O-methyl galactose from Juniperus tibetica

A water-soluble acidic polysaccharide containing 3-O-methyl galactose, named YB-PS4, was isolated from the twigs and leaves of Juniperus tibetica Kom. Its structure was characterized by monosaccharide composition analysis, methylation, and NMR spectroscopy. It was concluded that YB-PS4 had a backbone composed of→2,4)-α-Rhap-(1→, →3,5)-α-Araf-(1→, →2,4)-α-Galp-(1 → and →4)-α-GalpA-(1→, with branches of →2)-α-Rhap-(1→,→3)-α-Araf-(1 → and →2)-3-O-Me-α-Galp-(1→. The possible repetitive units were speculated and further analyzed by oligosaccharide analysis. YB-PS4 showed inhibitory effects on complement activation through the classical pathway (CH₅₀ = 94.23 ± 8.90 μg/mL) and alternative pathway (AP₅₀ = 194.76 ± 9.20 μg/mL). Preliminary mechanism study indicated that it interacted with C1q, C2, C3, C4 and C5. These studies pointed a way to understand the active constituents of J. tibetica and provided scientific bases for YB-PS4 as a complement inhibitor.

Anti-Complementary Components of Helicteres angustifolia

A first phenalenon derivative with an acetyl side chain at C-8, 8-acetyl-9-hydroxy-3-methoxy-7-methyl-1-phenalenon (compound 1), and a pair of new sesquilignan epimers at C-7″ of hedyotol C and hedyotol D analogs, hedyotol C 7″-O-β-d-glucopyranoside (compound 2) and hedyotol D 7″-O-β-d-glucopyranoside (compound 3) were isolated from the aerial parts of Helicteres angustifolia together with nine known compounds (4–12). Their structures were elucidated on the basis of spectroscopic methods, including mass spectroscopy, and 1D and 2D nuclear magnetic resonance. Eleven isolates exhibited anti-complementary activity. In particular, compounds 4 and 5 exhibited potent anti-complementary activities against the classical and alternative pathways with CH₅₀ values of 0.040 ± 0.009 and 0.009 ± 0.002 mM, and AP₅₀ values of 0.105 ± 0.015 and 0.021 ± 0.003 mM, respectively. The targets of compounds 4 and 5 in the complement activation cascade were also identified. In conclusion, the anti-complementary components of H. angustifolia possessed chemical diversity and consisted mostly of flavonoids and lignans in this study.

Chemical Structure and Immunomodulating Activities of an α-Glucan Purified from Lobelia chinensis Lour

A neutral α-glucan, named BP1, with a molecular mass of approximately 9.45 kDa, was isolated from Lobelia chinensis by hot-water extraction, a Q-Sepharose Fast Flow column and Superdex-75 column chromatography. Its chemical structure was characterized by monosaccharide analysis, methylation analysis and analysis of its FT-IR, high performance gel permeation chromatography (HPGPC) and 1D/2D-NMR spectra data. The backbone of BP1 consists of →₆α-d-Glcp¹→6,3α-d-Glcp¹→(₆α-d-Glcp¹)x-6,3α-d-Glcp¹-(₆α-d-Glcp¹)y→. The side chains were terminal α-d-Glcp¹→ and α-d-Glcp¹→ (₆α-d-Glcp¹)z→₄α-d-Glcp¹→₃α-d-Glcp¹→₄α-d-Glcp¹→ (x + y + z = 5), which are attached to the backbone at O-3 of 3,6α-d-Glcp¹. The results of the effect of BP1 on mouse macrophage cell line RAW 264.7 indicate that BP1 enhances the cell proliferation, phagocytosis, nitric oxide production and cytokine secretion in a dose-dependent manner. Because the inhibitor of Toll-like receptor 4 blocks the BP1-induced secretion of TNF-α and IL-6, we hypothesize that α-glucan BP1 activates TLR4, which mediates the above-mentioned immunomodulating effects.

Intestinal bacterial metabolism and anti-complement activities of three major components of the seeds of Entada phaseoloides

The present study aimed to investigate the metabolism of Entadae Semen by human fecal bacteria to clarify the relationship between its pharmacological activities and intestinal metabolism. Three major components (phaseoloidin, entadamide A-β-D-glucopyranoside and entadamide A) were isolated and identified from Entadae Semen and then incubated with human fecal microflora in vitro to investigate the metabolic processes. The metabolites were analyzed with high-performance liquid chromatography (HPLC). The anti-complement activities of the three components and their metabolites produced by human fecal microflora were evaluated in vitro using a hemolysis assay. Phaseoloidin and entadamide A-β-D-glucopyranoside were metabolized into their respective aglycones during the incubation process, which enhanced their anti-complement effects. These results indicated that the presence of intestinal bacteria likely plays an important role and that the pharmacological effects of Entadae Semen may be dependent on intestinal bacterial metabolism.

Morin hydrate augments phagocytosis mechanism and inhibits LPS induced autophagic signaling in murine macrophage

Morin, a natural flavonoid that is the primary bioactive constituent of the family Moraceae, has been found to be associated with many therapeutic properties. In this study, we evaluated the immunomodulatory activities of increasing concentration of morin hydrate in vitro. Three different concentrations of morin hydrate (5, 10, and 15μM) were used to evaluate their effect on splenocyte proliferation, phagocytic activity of macrophages, cytokine secretion and complement inhibition. We also evaluated the role of morin hydrate on lipopolysaccharide (LPS) induced autophagy. Our study demonstrated that morin hydrate elicited a significant increase in splenocyte proliferation, phagocytic capacity and suppressed the production of cytokines and nitric oxide in activated macrophages. Humoral immunity measured by anti-complement activity showed an increase in inhibition of the complement system after the addition of morin hydrate, where morin hydrate at 15μM concentration induced a significant inhibition. Depending on our results, we can also conclude that morin hydrate protects macrophages from LPS induced autophagic cell death. Our findings suggest that morin hydrate represents a structurally diverse class of flavonoid and this structural variability can profoundly affect its cell-type specificity and its biological activities. Supplementation of immune cells with morin hydrate has an upregulating and immunoprotective effect that shows potential as a countermeasure to the immune dysfunction and suggests an interesting use in inflammation related diseases.

Recent Progress of Research on Herbal Products Used in Traditional Chinese Medicine: the Herbs belonging to The Divine Husbandman's Herbal Foundation Canon ( Shén Nóng Běn Cǎo Jīng)

This article will review selected herbal products from Chinese Materia Medica that are used in Traditional Chinese Medicine. The herbs come from the upper, middle, and lower class medicines as listed in The Divine Husbandman's Herbal Foundation Canon (神農本草經 Shén Nóng Běn Cǎo Jīng). The review will focus on the active constituents of the herbs and their bioactivities, with emphasis on the most recent progress in research for the period of 2003 to 2011.

Isolation of an anti-complementary polysaccharide from the root of Bupleurum chinense and identification of its targets in complement activation cascade

AIM

To isolate and characterize the anti-complementary polysaccharide from the root of Bupleurum chinense.

METHODS

Bioactivity-guided fractionation and purification was used to obtain the anti-complementary polysaccharide from the hot-water extract of the root of Bupleurum chinense. The polysaccharide was characterized by various chemical and spectral analyses. The anti-complementary activities were evaluated by hemolytic assay in vitro. The action targets were identified in the system with individual complement-depleted sera.

RESULTS

A homogeneous polysaccharide BC-PS2 was isolated as an anti-complementary agent. It was identified as a branched polysaccharide with an average molecular weight about 2 000 KDa, composed of Glc, Ara, Gal, and Man in the ratio 3.5 : 2.4 : 2.0 : 1.0, respectively, along with a trace of Rha and Xyl, and only 1.11% of protein. The main linkages of the residues of BC-PS2 include terminal, 1, 6-linked, 1, 3-linked and 1, 3, 6-linked Glcp, terminal and 1, 5-linked Araf, terminal, 1, 4-linked, 1, 6-linked and 1, 4, 6-linked Galp, terminal, and, 1, 4-linked and 1, 4, 6-linked Manp. The bioassay experiments revealed that BC-PS2 inhibited complement activation on both the classical and alternative pathways, with CH50 and AP50 of (0.222 ± 0.013) and (0.356 ± 0.032) mg·mL(-1), respectively. Preliminary mechanism studies indicated that BC-PS2 interacted with C1q, C2, and C9 components.

CONCLUSION

The results demonstrated that BC-PS2 is an anti-complementary polysaccharide, and should be important constituent of the root of Bupleurum chinense for its application in the treatment of diseases associated with the excessive activation of complement system.

Two new phenolic glycosides from Gnaphalium affine D. Don and their anti-complementary activity

Two new phenolic glycosides, named gnaphaffine A and B (compounds 1 and 2), were isolated from Gnaphalium affine. together with six known compounds, including caffeic acid (3), everlastoside L (4), isorhamnetin-7-O-β-D-glucopyranoside (5), quercetin- 3-O-β-D-glucopyranoside (6), scutellarein-7-O-β-D-glucoside (7) and api-genin-7-O-β-D- glucopyranoside (8). Their structures were elucidated by spectroscopic methods, including ESI-MS and 2D NMR spectroscopy (HMQC and HMBC). All compounds were evaluated for their anti-complementary activity on the classical pathway of the complement system in vitro.

Influence of red algal sulfated polysaccharides on blood coagulation and platelets activation in vitro

The influence of sulfated polysaccharides (λ-, κ-, and κ/β-carrageenan and porphyran) - on platelet activation was studied. Carrageenans were much weaker inhibitors of a coagulation process than heparin, while porphyran had not that effect. Results of the aPTT and PT assays suppose that carrageenans affected mostly intrinsic pathway of coagulation, while their effect on the extrinsic pathway is extremely low (λ and κ/β) or absent (κ, LMW derivative of κ-carrageenan). λ-Carrageenan was the most potent anticoagulant agent in TT, aPTT, PT, and anti-factor Xa activity. This sample was also the strongest inhibitor of collagen-induced platelet aggregation in PRP. Generally, the correlation of anticoagulant and antithrombotic action in PRP is preserved for carrageenans but not for heparin. Carrageenans and porphyran affected platelet adhesion to collagen by influencing glycoprotein VI. Low molecular weight κ-carrageenan had a similar effect on platelet adhesion mediated with both major collagen receptors: integrin α2 β1 and glycoprotein VI as native polysaccharide had. Carrageenans resulted in activation of platelets under platelet adhesion mediated by integrin αIIb β3 with less degree than heparin. The least sulfated κ/β-carrageenan that possessed an inhibiting effect on thrombin- and collagen-induced aggregation of washed platelets and on the PT test but it had no significant effect on TT was the weakest promoter of integrin αIIb β3 mediated platelet activation. In summary, our study showed that the polysaccharide action was complex, since it depended on its molecular mass, sulfation degree, and monosaccharide contents (3,6-anhydrogalactose).

Flavone C-glycosides from the flowers of Trollius chinensis and their anti-complementary activity

Phytochemical investigation of ethanol extract from the flowers of Trollius chinensis Bunge resulted in the isolation of two new flavone C-glycosides (1-2), along with 10 known compounds (3-12). The structures of the new compounds were established as 6‴-(3-hydroxy-3-methylglutaroyl)-2″-O-β-d-galactopyranosyl orientin (1) and 6‴-(3-hydroxy-3-methylglutaroyl)-2″-O-β-d-galactopyranosyl vitexin (2) on the basis of various spectroscopic analysis (including different 1D and 2D NMR spectroscopies, high-resolution electrospray ionization mass spectrometry) and chemical evidences. Bioassay showed that eight flavonoids inhibited complement activation on the classic pathway in vitro, with their IC50 values ranging from 0.88 to 4.02 mM, which may contribute to the applications of the herb in treatment of acute respiratory distress syndrome, etc.

Anti-metastatic effect of polysaccharide isolated from Colocasia esculenta is exerted through immunostimulation

In the present study, an edible corm of the plant Colocasia esculenta, commonly known as Taro was extracted with cold water (4˚C). Finally, 10.44 g (1.04%) of the crude polysaccharide (Taro-0) was obtained from Taro. The purified active compound (Taro-4-I) was isolated using DEAE-Sepharose FF and Sephadex G-100. The anti-complementary activity of Taro-4-I (57.3±4.5%) was similar to that of polysaccharide K (used as the positive control). The molecular weight of Taro-4-I was 200 kDa and it was a polysaccharide composed of 64.4% neutral sugars and 35.6% uronic acid. Taro-4-I activated the complement system through the classical and alternative pathways. The treatment of peritoneal macrophages with Taro-4-I significantly increased the production of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. However, IL-12 production showed maximal activity at 56 µg/ml and subsequently decreased. Splenocytes obtained from mice which were administered Taro-4-I intravenously showed a higher toxicity to Yac-1 cells compared to those obtained from untreated mice in a effector‑to‑target (E/T) ratio-dependent manner. The group treated with 50 µg/ml Taro-4-I showed a significantly increased toxicity to Yac-1 cells compared to the group treated with 500 µg/ml Taro-4-I. The administration of Taro-4-I significantly inhibited the lung metastasis of B16BL6 melanoma cells. However, the group treated with 50 µg/mouse Taro-4-I had a significantly lower number of tumors compared to the group injected with 500 µg/mouse Taro-4-I.

Validation of a HPLC-tandem MS/MS method for pharmacokinetics study of (+)-pinoresinol-di-β-D-glucopyranoside from Eucommia ulmoides Oliv extract in rats' plasma

Natural plant compounds have an unexceptional influence in pharmacy as they provide an uncountable number of invaluable lead molecules. Phytochemical researches nowadays focus on bio-assay guided revealing of the therapeutic profile and synergism of medicinal herbs and their constituents. Assessing the clinical and biological potential and determining the pharmacokinetics of herbal constituents is also an area of much interest. This work was conducted in order to carry out a sensitive liquid chromatography tandem mass spectrum (HPLC-MS/MS) method for the pharmacokinetics study of (+)-pinoresinol-di-β-D-glucopyranoside (PG) in rats' plasma after oral administration of Eucommia ulmoides Oliv extract. The validated method was by means of linearity, precision, matrix effect and recovery so that it could be used for the pharmacokinetic study of PG. The obtained pharmacokinetic parameters shown that PG pertains to one-compartment model and 95% of PG was eliminated within 12h.

Beneficial effect of Eucommia polysaccharides on systemic lupus erythematosus-like syndrome induced by Campylobacter jejuni in BALB/c mice

The stem bark of Eucommia ulmoides Oliv. is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia in traditional Chinese medicine. This study was to determine whether the crude polysaccharides (EUPs) isolated from the stem bark of E. ulmoides had beneficial effects on lupus-like syndrome in mice. BALB/c mice were immunized with CJ-S(131) in Freund's complete adjuvant on day 0, and then boosted on day 14. EUPs 15 or 30 mg kg(-1)·day(-1), or prednisone 5 mg kg(-1)·day(-1) was given to BALB/c mice intragastrically from day 0 to 34. Treatment with EUPs 15 or 30 mg kg(-1)·day(-1) for 35 days protected kidney from glomerular injury with reduced immunoglobulin deposition and lowered proteinuria. The increased production of serum autoantibodies and total immunoglobulin G (IgG) was also inhibited. These findings suggested that Eucommia polysaccharides had a beneficial effect on systemic lupus erythematosus-like syndrome induced by CJ-S(131) in BALB/c mice.

Progression of atherosclerotic lesions in the arteries and related gene expression: protective effect of phytonutrients

We investigated the effect of the phytocompound Denshici-to-Chiusei (DTS) on the atherogenesis in apolipoprotein E(-/-)/low-density lipoprotein receptor(-/-) (apoE(-/-)/LDL receptor(-/-)) mice (E0). E0 mice were fed for 16 weeks with: (1) placebo or (2) 25 mg or (3) 50 mg of DTS/day. Aortic lesions were reduced by 38% (p < 0.01) in mice fed 50 mg/day, whereas peritoneal macrophages after both dosages had a 45%-60% lower (p < 0.01) capacity to oxidize LDL and to degrade it. This was associated with reduced LDL-associated lipoperoxides and a 22% inhibition (p < 0.05) in LDL aggregation. Tumor necrosis factor-alpha (TNF-alpha) expression and immunoreactivity in the aortic media increased five-fold, but this was significantly mitigated by DTS (50 mg > 25 mg) (p < 0.05). DTS significantly attenuated inflammatory mechanisms preceding atherogenesis with reduced LDL susceptibility to oxidation-aggregation.