Characterization and comparison of bioactive polysaccharides from the tubers of Gymnadenia conopsea

Novel glucomannan-like polysaccharide from Lycium barbarum L. ameliorates renal fibrosis via blocking macrophage-to-myofibroblasts transition

The macrophage to myofibroblasts transition (MMT) has been reported as a newly key target in renal fibrosis. Lycium barbarum L. is a traditional Chinese medicine for improving renal function, in which its polysaccharides (LBPs) are the mainly active components. However, whether the role of LBPs in treating renal fibrosis is related to MMT process remain unclear. The purpose of this study was to explore the relationship between the regulating effect on MMT process and the anti-fibrotic effect of LBPs. Initially, small molecular weight LBPs fractions (LBP-S) were firstly isolated via Sephadex G-100 column. Then, the potent inhibitory effect of LBP-S on MMT process was revealed on bone marrow-derived macrophages (BMDM) model induced by TGF-β. Subsequently, the chemical structure of LBP-S was elucidated through monosaccharide, methylation and NMR spectrum analysis. In vivo biodistribution characteristics studies demonstrated that LBP-S exhibited effectively accumulation in kidney via intraperitoneal administration. Finally, LBP-S showed a satisfactory anti-renal fibrotic effect on unilateral ureteral obstruction operation (UUO) mice, which was significantly reduced following macrophage depletion. Overall, our findings indicated that LPB-S could alleviate renal fibrosis through regulating MMT process and providing new candidate agents for chronic kidney disease (CKD) related fibrosis treatment.

Structural elucidation a complex galactosyl and glucosyl-rich pectin from the pericarp of immature fruits of Juglans mandshurica Maxim

A glucosyl-rich pectin, JMMP-3 (Mw, 2.572 × 104 g/mol, O-methyl % = 3.62%), was isolated and purified from the pericarp of the immature fruit of Juglans mandshurica Maxim. (QingLongYi). The structure of JMMP-3 was studied systematically by infrared spectroscopy, monosaccharide compositions, methylation analysis, partial acid hydrolysis, and 1/2D-NMR. The backbone of JMMP-3 possessed a smooth region (→ 4GalA1 →) and a hairy region (→ 4GalA1 → 2Rha1 →) with a molar ratio of 2: 5. The substitution of four characteristic side chains (R1-R4) occurs at C-4 of → 2,4)-α-Rhap-(1→, where R1 is composed of → 5)-α-Araf-(1→, R2 is composed of → 4)-β-Galp-(1 → and β-Galp-(1→, R3 is composed of α-Glcp-(1→, →4)-α-Glcp-(1 → and → 4,6)-α-Glcp-(1→, and R4 is composed of → 5)-α-Araf-(1→, β-Galp-(1→, → 4)-β-Galp-(1→, → 3,4)-β-Galp-(1→, → 4,6)-β-Galp-(1 → and → 2,4)-β-Galp-(1 → . In addition, the antitumor activity of JMMP-3 on HepG2 cells was preliminarily investigated.

Separation and purification of benzylester glucosides and derivatives from tubers of Gymnadenia conopsea (L.) R. Br. by linear gradient counter-current chromatography combined with elution-extrusion mode

Tubers of Gymnadenia conopsea (L.) R. Br. (Orchidaceae), a traditional medicine and food homologous plant, has a broad application and development prospect in the food and drug industries. Benzylester glucosides, the main effective active components in this plant, are difficult to separate due to their similar structures and high polarity. In this study, linear gradient counter-current chromatography was used to separate benzylester glucosides and derivatives, combined with elution-extrusion mode. The main separation parameters were optimized, including the ratio of mobile phase and sample loading. Finally, seven compounds were successfully separated, including 4-hydroxybenzyl alcohol (1), 4-hydroxybenzaldehyde (2), dactylorhin B (3), loroglossin (4), dactylorhin A (5), 4-(ethoxymethyl) phenol (6), and militarine (7). The structures were analyzed by mass spectrometry and nuclear magnetic resonance spectrometry. According to our findings, the established method was an efficient approach to separate benzylester glucosides and derivatives from tubers of G. conopsea. The established strategy could be applied to purify other similar high-polarity compounds from complex natural products.

Characterization and comparison of cardiomyocyte protection activities of non-starch polysaccharides from six ginseng root herbal medicines

Ginseng is rich of polysaccharides, however, the evidence supporting polysaccharides to distinguish various ginseng species is rarely reported. Focusing on six root ginseng (e.g., Panax ginseng-PG, P. quinquefolius-PQ, P. notoginseng-PN, red ginseng-RG, P. japonicus-PJ, and P. japonicus var. major-PJM), the contained non-starch polysaccharides (NPs) were structurally characterized and compared by both the chemical and biological evaluation. Holistic fingerprinting at three levels (the NPs and the acid hydrolysates involving oligosaccharides and monosaccharides) utilized various chromatography methods, and the treatment of H9c2 cells with the NPs by OGD and H2O2-induced injury models was used to assess the protective effect. NPs from six Panax herbal medicines occupied about 20 % of the total polysaccharides, which were of the highest content in RG and the lowest in PN. NPs from six ginseng exhibited weak differentiations in the molecular weight distribution, while marker oligosaccharides were found to distinguish PN and RG from the others. Glc and GalA were more abundant in the NPs for PG and RG, respectively. NPs from PQ (100/200 μg/mL) showed significant cardiomyocyte protection effect by regulating the mitochondrial functions. This work further testifies the role of polysaccharides in quality control of herbal medicine, with new markers discovered beneficial to distinguish the ginseng.

Characterization and Comparison of Bioactive Polysaccharides from Grifola frondosa by HPSEC-MALLS-RID and Saccharide Mapping Based on HPAEC-PAD

Grifola frondosa polysaccharides (GFPs) from different regions in China were characterized and compared using HPSEC-MALLS-RID and saccharide mapping based on HPAEC-PAD analysis for achieving and improving its quality control. The results showed that HPSEC chromatograms and molecular weight distributions of GFPs were similar. The average contents of each polysaccharide fraction (Peaks 1, 2, and 3) showed that Peak 3 was the main component and much higher than the other two polysaccharide fractions, which also contained protein. The result of saccharide mapping showed that α-1,4-glycosidic, β-1,4-glycosidic and few β-1,3-glycosidic linkages were existed in GFPs. The similarity result showed that HPAEC-PAD fingerprints of the oligosaccharide fragments after hydrolysis by endoglycosidase were certainly different, especially α-amylase with a mean similar index of only 0.781 ± 0.207. The result of hierarchical cluster analysis (HCA) showed that different batches of GFPs from China can be divided into different clusters. Furthermore, immune-enhancing activity based on RAW 264.7 cells showed significant differences among different GFPs. Based on grey relational analysis (GRA), the fractions of Peak 3 were regarded as the major contributors to its immuno-enhancing activity in GFPs. Overall, the implications from these results were found to be stable, comprehensive, and valid for improving the quality control of GFPs.

Optimization of the extraction process and metabonomics analysis of uric acid-reducing active substances from Gymnadenia R.Br. and its protective effect on hyperuricemia zebrafish

Background

As Gymnadenia R.Br. (Gym) has an obvious uric acid-lowering effect, but its specific bioactive substances and mechanism are still unclear. The key metabolites and pathways used by Gym to reduce uric acid (UA) were identify.

Methods

An optimized extraction process for urate-lowering active substances from Gym was firstly been carried out based on the xanthine oxidase (XOD) inhibition model in vitro; then, the Ultra-high-performance liquid chromatography and Q-Exactive mass spectrometry (UHPLC-QE-MS) based on non-targeted metabolomics analysis of Traditional Chinese Medicine were performed for comparison of Gym with ethanol concentration of 95% (low extraction rate but high XOD inhibition rate) and 75% (high extraction rate but low XOD inhibition rate), respectively; finally, the protective effect of ethanolic extract of Gym on zebrafish with Hyperuricemia (referred to as HUA zebrafish) was explored.

Results

We found that the inhibition rate of Gym extract with 95% ethanol concentration on XOD was 84.02%, and the extraction rate was 4.32%. Interestingly, when the other conditions were the same, the XOD inhibition rate of the Gym extract with 75% ethanol concentration was 76.84%, and the extraction rate was 14.68%. A total of 539 metabolites were identified, among them, 162 different metabolites were screened, of which 123 were up-regulated and 39 were down-regulated. Besides significantly reducing the contents of UA, BUN, CRE, ROS, MDA, and XOD activity in HUA zebrafish by Gym and acutely reduce the activity of SOD.

Conclusion

Along with the flavonoids, polyphenols, alkaloids, terpenoids, and phenylpropanoids, the ethanolic extract of Gym may be related to reduce the UA level of Gym.

Recent advances in qualitative and quantitative analysis of polysaccharides in natural medicines: A critical review

Polysaccharides from natural medicines, being safe and effective natural mixtures, show great potential to be developed into botanical drugs. However, there is yet one polysaccharide-based case that has fulfilled the Botanical Guidance definition of a botanical drug product. One of the reasons is the analytical methods commonly used for qualitative and quantitative analysis of polysaccharides fall far behind the quality control criteria of botanical drugs. Here we systemically reviewed the recent advances in analytical methods. A critical evaluation of the strength and weaknesses of these methods was provided, together with possible solutions to the difficulties. Mass spectrometry with or without robust chromatographic separation was increasingly employed. And scientists have made significant progress in simplifying polysaccharide quantification by depolymerizing it into oligosaccharides. This oligosaccharides-based strategy is promising for qualitative and quantitative analysis of polysaccharides. And continuous efforts are still needed to develop a standardized quality control method that is specific, accurate, repeatable, and applicable for analyzing individual components in natural medicine formulas.

A quantitative method for polysaccharides based on endo-enzymatic released specific oligosaccharides: A case of Lentinus edodes

Polysaccharides exhibit multiple pharmacological activities, which are closely related to their structural characteristics. Therefore, quantitative quality control of polysaccharides based on chemical properties is of importance for their applications. However, polysaccharides are mixed macromolecular compounds that are difficult to separate, and the lack of standards made direct quantification more difficult. In this study, we proposed a new quantitative method based on the released specific oligosaccharides for polysaccharides from Lentinus edodes (shiitake) and other related fungi. Specific oligosaccharides were firstly released from polysaccharides using 1,3-β-glucanase, then derivatized with 2-aminobenzamide (2-AB), which further separated by hydrophilic interaction chromatography (HILIC) and quantitatively determined by UPLC coupled with fluorescence detector (FLR). Laminaritriose was used as the universal standard for quantification of all the oligosaccharides. This method was validated according to linearity, limit of detection, limit of quantitation, precision, accuracy, repeatability and stability. In addition, the four specific oligosaccharides released from polysaccharides in L. edodes were qualitatively analyzed by extracted ion chromatogram (EIC) from UPLC-MS profiles, which were identified to be disaccharide, trisaccharide and tetrasccharide. The proposed strategy not only realized the quantitative analysis of polysaccharides by UPLC-FLR, but also could achieve the qualitative distinction of different polysaccharides.

Multiple fingerprint profiling for quality evaluation of polysaccharides and related biological activity analysis of Chinese patent drugs: Zishen Yutai Pills as a case study

ETHNOPHARMACOLOGICAL RELEVANCE

Zishen Yutai Pills (ZYP), a famous traditional Chinese patent medicine, has been widely applied to avoid recurrent miscarriage and treat threatened abortion. Polysaccharides of ZYP (ZYPPs) play an essential role in the theraprutic effects of ZYP. However, the complex compositions of ZYP and the complicated structure of ZYPPs have posed great challenges and barriers to the quality evaluation of ZYP.

AIM OF THE STUDY

To identify and characterize the ZYPPs for better quality control of ZYP, a reliable and valid quality control system was established in this study.

MATERIALS AND METHODS

A multi-fingerprint profile strategy based on HPSEC-MALL-RID, FT-IR, and HPLC (complete acid digested fingerprint, partial acid digested fingerprint and enzymatically digested fingerprint) was established to identify and discriminate the chemical structure of ZYPPs. Besides, the purpose of revealing the relationships between structure and biological activity of ZYPPs, their chemical characteristics, in vitro antioxidant and anti-glycation activities were investigated and discussed.

RESULTS

The similarity evaluation of ZYPPs indicated ZYPPs from different batches showed a high similarity based on the correlation coefficient values of multi-fingerprints. Furthermore, ZYPPs exhibited remarkable antioxidant and antiglycation properties, which might be attributed to their molecular weights and the content of uronic acids.

CONCLUSIONS

These results indicated that the multiple fingerprint technique was reliable and effective for the improvement of quality control of ZYPPs, suggesting the multiple fingerprint technique could also be potentially applied as a valid and feasible strategy to control the quality of polysaccharide-enriched herbal medicines.

Structural characterization, antioxidant activity, and immunomodulatory activity of non-starch polysaccharides from Chuanminshen violaceum collected from different regions

Chuanminshen violaceum has been used as an important traditional Chinese medicine and a popular tonic food in China. Polysaccharides are considered the major bioactive components in C. violaceum. In this study, in order well understand the chemical structures and bioactivities of non-starch polysaccharides in C. violaceum (CVPs), the physicochemical structures, antioxidant activities, and immunomodulatory activities of CVPs in C. violaceum collected from different regions of China were investigated and compared. Results showed that the constituent monosaccharides and Fourier transform infrared spectra of CVPs in C. violaceum collected from different regions were similar. However, their molar ratios of constituent monosaccharides, molecular weights, and contents of uronic acids were different. Furthermore, CVPs exerted remarkable antioxidant activities (ABTS and nitric oxide radical scavenging capacities) and immunomodulatory activities (promoted production of nitric oxide, IL-6, and TNF-α from RAW 264.7 macrophages in vitro). Meanwhile, the antioxidant and immunomodulatory activities of CVPs extracted from C. violaceum also varied by cultivated regions. Moreover, results indicated that the antioxidant and immunomodulatory activities of CVPs were closely correlated to their α-1,4-d-galactosiduronic linkages. Results are helpful for better understanding of the structure-bioactivity relationships of CVPs, and beneficial for the improvement of their applications in pharmaceutical and functional food industries.

Structural characteristics, rheological properties, and biological activities of polysaccharides from different cultivars of okra (Abelmoschus esculentus) collected in China

In order to well understand the physicochemical characteristics and biological activities of polysaccharides (OPPs) from different cultivars of okra collected in China, the chemical characteristics, rheological properties, antioxidant activities, in vitro binding properties, and in vitro inhibitory effects on α-glucosidase of polysaccharides from five representative okra cultivars, including 'Lvjian', 'Kalong8', 'Shuiguo', 'Taiwanwufu', and 'Kalong3', were investigated and compared. Results showed that the constituent monosaccharides of OPPs were similar, which composed of rhamnose, galacturonic acid, galactose, and arabinose. However, their weight-average molecular weights varied from 2.76 × 10³ to 4.20 × 10³ kDa, and from 0.11 × 10³ to 0.90 × 10³ kDa, respectively. The uronic acids and degrees of esterification of OPPs ranged from 39.32% to 61.68%, and from 21.66% to 30.02%, respectively. OPPs exhibited typical shear-thinning behavior and viscoelastic properties. Furthermore, OPPs exhibited remarkable antioxidant activities, in vitro binding capacities, and inhibitory effects on α-glucosidase, which might be attributed to their relatively high content of uronic acids, high degrees of esterification, and high molecular weights. Results are helpful for better understanding of the physicochemical structures and bioactivities of OPPs, and OPPs had good application prospects as functional food ingredients for industrial applications.

Physicochemical properties, immunostimulatory activity of the Lachnum polysaccharide and polysaccharide-dipeptide conjugates

The physicochemical properties and the immunoregulatory actions in vitro of an exopolysaccharide from Lachnum (LEP) and its conjugation with a dipeptide (LEP-RH) were investigated aiming to improve their functional characteristics. The structure characteristic of the LEP and LEP-RH were determined via FT-IR and NMR. The physicochemical properties were evaluated by scanning electron microscopy (SEM), rheometer, and differential scanning calorimeter (DSC). SEM results showed that LEP-RH had a rough surface and relatively loose distribution that different from LEP. Rheological studies of LEP and LEP-RH at the same concentration indicated that LEP and LEP-RH have similar shear-thinning behaviors and gel-like structures, while LEP-RH has a better thermal stability than LEP. Bioassay results showed that treatment with the higher dosage (200 μg/mL) of LEP and LEP-RH stimulated the proliferation, cytokine secretion (IL-2, IL-6 and TNF-α) of RAW264.7 macrophages.

Advanced strategies for quality control of Chinese medicines

Quality control is always the critical issue for Chinese medicines (CMs) with their worldwide increasing use. Different from western medicine, CMs are usually considered that multiple constituents are responsible for the therapeutic effects. Therefore, quality control of CMs is a challenge. In 2011, the strategies for quantification, related to the markers, reference compounds and approaches, in quality control of CMs were reviewed (Li, et al., J. Pharm. Biomed. Anal., 2011, 55, 802-809). Since then, some new strategies have been proposed in these fields. Therefore, the review on the strategies for quality control of CMs should be updated to improve the safety and efficacy of CMs. Herein, novel strategies related to quality marker discovery, reference compound development and advanced approaches (focused on glyco-analysis) for quality control, during 2011-2016, were summarized and discussed.

Characterization of Polysaccharides with Antioxidant and Hepatoprotective Activities from the Edible Mushroom Oudemansiella radicata

The preliminary structure, in vitro antioxidant and in vivo hepatoprotective activities of water-soluble polysaccharides (ORWP) and alkali-soluble polysaccharides (ORAP), prepared from the mushroom Oudemansiella radicata, were investigated. Both ORWP and ORAP were heteropolysaccharides with mannose, glucose and galactose being the main monosaccharide components. Regarding the antioxidant activities, ORWP and ORAP showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, hydrogen peroxide scavenging activity and lipid peroxidation inhibitory effects, as well as moderate reducing power and Fe²⁺ chelating activity. For the hepatoprotective activity, administration of ORWP and ORAP prevented the increase in serum alanine aminotransferase and aspartate aminotransferase activities in a carbon tetrachloride-induced acute liver damage model, suppressed hepatic malondialdehyde formation and stimulated the activities of hepatic superoxide dismutase and glutathione peroxidase. Thus, we speculate that ORWP and ORAP may protect the liver from CCl₄-induced hepatic damage via antioxidant mechanisms.

Gymnadenia conopsea (L.) R. Br.: A Systemic Review of the Ethnobotany, Phytochemistry, and Pharmacology of an Important Asian Folk Medicine

Gymnadenia conopsea (L.) R. Br. (Orchidaceae) is a perennial herbaceous orchid plant that grows widely throughout Europe and in temperate and subtropical zones of Asia. In China, its tuber has been used in traditional Chinese medicines, Tibetan medicines, Mongolian medicines and other ethnic medicines, and taken to treat numerous health conditions. The present paper provides a review of the traditional uses, phytochemistry, biological activities, and toxicology to highlight the future prospects of the plant. More than 120 chemical compounds have been isolated, and the primary components are glucosides, dihydrostilbenes, phenanthrenes, aromatic compounds, and other compounds. G. conopsea and its active constituents possess broad pharmacological properties, such as the tonifying effect, anti-oxidative activity, anti-viral activity, immunoregulatory, antianaphylaxis, antigastric ulcer, sedative, and hypnotic activities, etc. However, overexploitation combined with the habitat destruction has resulted in the rapid decrease of the resources of this plant, and the sustainable use of G. conopsea is necessary to study. Meanwhile, the toxicity of this plant had not been comprehensively studied, and the active constituents and the mechanisms of action of the tuber were still unclear. Further, studies on G. conopsea should lead to the development of scientific quality control and new drugs and therapies for various diseases; thus, its use and development require additional investigation.

Structural characterization and hypolipidemic effect of Cyclocarya paliurus polysaccharide in rat

Polysaccharide is one of the important active ingredients of Cyclocarya paliurus (Batal.) Iljinskaja leaves. The aims of this work were to analyze the structure of the polysaccharide of Cyclocarya paliurus (Batal.) Iljinskaja leaves (CPP), and to investigate the antihyperlipidemic effect of CPP on high-fat emulsion (HFE)-induced hyperlipidaemic rats. CPP, comprised of two polysaccharides with average molecular weight (Mw) of 1.35×10(5)Da and 9.34×10(3)Da, was consisted of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.00:2.23:0.64:0.49:0.63:4.16. Oral administration of CPP could significantly decrease levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), increase high density lipoprotein (HDL-C) in hyperlipidemic rats. CPP exerts therapeutic effects on hyperlipidaemic rats, by up-regulating expressions of adipose triglyceride lipase (ATGL) and peroxisome proliferator-activated receptor alpha (PPARα), via down-regulating fatty acid synthase (FAS) and hydroxy methylglutaryl coenzyme A reductase (HMG-CoA). This study demonstrates that CPP may be beneficial for the treatment of hyperlipidemia.

Characterization and hypoglycemic activity of a β-pyran polysaccharides from bamboo shoot (Leleba oldhami Nakal) shells

The bamboo shoot (Leleba oldhami Nakal) shell is a by-product during bamboo shoot processing. It is a cheap and available resource for dietary polysaccharides. Herein, a novel polysaccharide BSSP2a was isolated and characterized from the bamboo shoot shell polysaccharides, and it was identified as a homogeneous highly-branched beta type pyran polysaccharide with a molecular weight of 1.63×10(4)kDa, which consisted of arabinose, xylose, mannose, glucose and galactose at a molar ratio of 20.4:4.9:1:3.4:20.6. The crude polysaccharides (BSSP) from the bamboo shoots shell showed hypoglycemic activity on the high fat diet and streptozotocin induced diabetic mice in a dose-dependent manner. The administration of high dose BSSP (400mg/kg) improved body weight loss and serum insulin loss, and significantly decreased the blood glucose level, serum triglycerides as well as total cholesterol levels by 48.7%, 34.8% and 26.5%, respectively. The results highlight the potential of the bamboo shoot shell polysaccharides as a natural anti-diabetic agent.