Jianhua Xie

Purification, physicochemical characterisation and anticancer activity of a polysaccharide from Cyclocarya paliurus leaves

A Cyclocarya paliurus (Batal.) Iljinskaja polysaccharide (CPP) was isolated and purified by hot water extraction, ethanol precipitation, deproteinisation and anion-exchange chromatography. Its physicochemical properties were characterised by gel permeation chromatography (GPC), gas chromatography-mass spectrometry (GC-MS), thermal gravimetric analysis (TGA), Fourier transform infrared spectrometry (FTIR), UV-visible spectrophotometry, dynamic light scattering (DLS) and viscometry analysis. The anticancer effect of CPP in human gastric cancer HeLa cells was also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the molecular weight of CPP was 900 kDa, and it contained 64.8% total sugar, 23.5% uronic acid, 9.26% protein, and six kinds of monosaccharides, including glucose, rhamnose, arabinose, xylose, mannose and galactose, with molar percentages of 32.7%, 9.33%, 30.6%, 3.48%, 10.4%, and 13.5%, respectively. Furthermore, the results showed that CPP exhibited a strong inhibition effect on the growth of human gastric cancer HeLa cells.

Ultrasonic-assisted extraction, antimicrobial and antioxidant activities of Cyclocarya paliurus (Batal.) Iljinskaja polysaccharides

Recently, renewed interest has grown in the use of ultrasonic-assisted extraction as an alternative approach to the traditional extraction methods. In this study, this novel extraction method was used to isolate polysaccharides from Cyclocarya paliurus (Batal.) Iljinskaja, and response surface methodology (RSM) was employed to optimize the extraction conditions. The optimal conditions for the extraction of polysaccharides were determined to be the ratio of liquid to solid of 8, extraction time of 59 min and extraction temperature of 58 °C. Under these optimal conditions, the yield of polysaccharides obtained was 4.91 ± 0.11%, which was well matched with the value predicted by the model. In vitro antioxidant assays showed that the polysaccharides exhibited strong DPPH radicals (92.09% at 0.25 mg/ml) and self-oxidation of 1,2,3-phentriol (37.22% at 1 mg/ml) scavenging activities, moderate hydroxyl radicals (43.18% at 1 mg/ml) scavenging activity and lipid peroxidation inhibitory effect (31.66% at 1 mg/ml). In addition, the polysaccharides showed moderate antimicrobial activity.

Extraction, chemical composition and antioxidant activity of flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja leaves.

Microwave-assisted extraction of flavonoids from Cyclocarya paliurus (Batal.) Iljinskaja leaves, its chemical composition and antioxidant activity were investigated in this study. The influences of parameters including temperature, extraction time, ratio of material to solvent and solvents on the yield of flavonoids were studied. The optimal conditions were determined and the quadratic response surfaces were drawn from the mathematical models. The maximum extraction yield of 15.64 mg/g was achieved at temperature of 76.8 °C, extraction time of 15 min, alcohol concentration of 63.2% and ratio of solvent to material of 21.4:1. Five main constituents in the extract including quercetin-3-O-β-D-glucuronide, quercetin, kaempferol-3-O-β-D-glucuronide, kaempferol-7-O-α-L-rhamnoside and kaempferol were identified by LC-MS. In vitro antioxidant assays showed that the extract exhibited a strong DPPH radical-scavenging ability with IC50 value of 0.146 mg/mL. Results indicated that MAE was a suitable approach for the selective extraction of flavonoids from C. paliurus (Batal.) Iljinskaja leaves.

Advances on Bioactive Polysaccharides from Medicinal Plants

In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

Analysis of monosaccharide composition of Cyclocarya paliurus polysaccharide with anion exchange chromatography

A simple, rapid and sensitive analytical method for the determination of monosaccharide composition in Cyclocarya paliurus polysaccharide was developed and validated. This method was based on hydrolysis of the polysaccharides followed by high-performance anion-exchange chromatography analysis. The effects of sodium hydroxide concentration and column temperature on retention and separation of the monosaccharide were investigated with Carbo PAC™ PA10 analytical column. The established method was validated and the results showed that this method had good linearity (R(2), 0.9987-0.9999), adequate accuracy (98.53-102.13% recovery), high precision (relative standard deviation <3.8%) and sensitive detection limits (2.57-7.86 nM), with a simple preparation of the samples (no need to derivatize the samples) and short run time (20 min). The results showed that the C. paliurus polysaccharide consisted of rhamnose, arabinose, galactose, glucose, mannose and xylose in the molar ratio of 1.00:1.85:3.26:3.12:0.85:0.29.

Sulfated polysaccharides from Cyclocarya paliurus reduce H2O2-induced oxidative stress in RAW264.7 cells

In this study, two sulfated polysaccharides (S-CP1-4 and S-CP1-8) from Cyclocarya paliurus were produced by chlorosulfonic acid-pyridine method. Hydrogen peroxide (H2O2) was used to develop an oxidative stress model in the mouse macrophage cell line RAW264.7. Effects of the two sulfated polysaccharides on H2O2-induced oxidative stress were investigated. The results showed that S-CP(1-8) improved the viability of the H2O2-induced stressed RAW264.7 cells, as well as inhibited the lipid oxidation as determined by the level of malondialdehyde (MDA). Meanwhile, treatment with S-CP(1-4) increased superoxide dismutase (SOD) activity in these cells. The sulfated polysaccharides were found to have a better protective effect against H2O2-induced oxidative stress as compared to the native polysaccharide. Scanning electron microscopy also showed a significant change in the surface morphology of sulfated polysaccharides, but the degradation of main chain of polysaccharides was unconspicuous according to the results of monosaccharide composition. In addition, the sulfated polysaccharides had noticeable DPPH radical scavenging activity. In summary, our results demonstrated that H2O2 was able to induce oxidative stress in RAW264.7 cells, and sulfated group might play an important role in resistance to H2O2-induced oxidative damage.

Preparation, characterization and antioxidant activities of acetylated polysaccharides from Cyclocarya paliurus leaves.

In this study, polysaccharides extracted from Cyclocarya paliurus leaves were modified to obtain its three acetylated derivatives, Ac-CP1, Ac-CP2, and Ac-CP3. The physicochemical characteristics and antioxidant activities of acetylated derivatives were investigated. The results of chemical and FT-IR spectrum analysis showed differences between acetylated derivatives and native C. paliurus polysaccharide, which revealed that the acetylation were successful. Relative to unmodified polysaccharide, the protein contents of acetylated derivatives decreased, while carbohydrate values increased. The molecular weight (Mw) of acetylated derivatives were approximately 1.05-1.09×10(6)Da and were mainly composed of Ara, Gal, Glc, Man, GalA. Ac-CP1 with relatively low degree of substitution (0.13±0.01) exhibited excellent antioxidant activity in DPPH radical assay (95.21±0.89%), and also had strong chelating activity on β-carotene-linoleic acid assay (34.64±2.07%) at 0.5mg/ml. In addition, scanning electron microscope (SEM) observations suggested that acetylation could change the morphology and structure of polysaccharides from C. paliurus leaves.

Simultaneous analysis of 18 mineral elements in Cyclocarya paliurus polysaccharide by ICP-AES

The contents of 18 kinds of mineral elements in Cyclocarya paliurus polysaccharide samples were determined by ICP-AES. The limits of detection (LOD) of the method for 18 elements were in the range of 0.01-3.80 mg/kg. The average recoveries obtained by the standard addition method were found between 94.34% and 105.69% (RSD, 1.01-4.23%). The results showed that C. paliurus polysaccharides were abundant in major and trace elements which are healthy for human body. The contents of Ca, Al, Mg, K, Fe, Mn and P were very high, ranging from 274.5±10.3 to 5980.0±102.7 mg/kg, while the contents of Zn, Na, Se, Cr, Pb, Cu and As ranged from 0.9±0.1 to 37.1±4.2 mg/kg. Finally, the levels of Ni, Cd, V and Co were not detected in the samples. ICP-AES is a simple, precise and efficient method for the determination of many mineral elements in polysaccharide samples simultaneously.

Carboxymethylation of polysaccharide from Cyclocarya paliurus and their characterization and antioxidant properties evaluation

In this study, three chemically carboxymethyl polysaccharides (CM-CPs) were derived from Cyclocarya paliurus polysaccharides. The physicochemical properties and antioxidant activity in vitro of carboxymethyl derivatives were determined. The results of degree of substitution and FT-IR analysis showed the carboxymethylation of polysaccharides were successful. Compared with unmodified polysaccharides, the contents of carbohydrate and protein were decreased while CM-CP3 with highest DS value had more uronic acid. The carboxymethyl derivatives was mainly composed of Ara, Gal, Glc, Man, GalA, with a molecular weight (Mw) of 1.03-1.08 × 10(6)Da. Compared with the native polysaccharide, the CM-CP3 with highest DS and Mw exhibited the highest antioxidant activity in β-carotene-linoleic acid assay. However, the superoxide radical and hydroxyl radical scavenging activity were decreased by CM-CPs. These results demonstrated appropriate carboxymethylation modification could enhance the potential of C. paliurus polysaccharide as oxidation inhibitor.

Biological activities and pharmaceutical applications of polysaccharide from natural resources: A review

Pharmacotherapy using natural substances can be currently regarded as a very promising future alternative to conventional therapy. As biological macromolecules, polysaccharide together with protein and polynucleotide, are extremely important biomacromoleules which play important roles in the growth and development of living organism. Polysaccharide is important component of higher plants, membrane of the animal cell and the cell wall of microbes. It is also closely related to the physiological functions. Recently, increasing attention has been paid on polysaccharides as an important class of bioactive natural products. Numerous researches have demonstrated the bioactivities of natural polysaccharides, which lead to the application of polysaccharides in the treatment of disease. In this paper, the various aspects of the investigation results of the bioactivities of polysaccharides were summarized, including its diversity pharmacological applications, such as immunoregulatory, anti-tumor, anti-virus, antioxidation, and hypoglycemic activity, and their application of polysaccharides in the treatment of disease are also discussed. We hope this review can offer some theoretical basis and inspiration for the mechanism study of the bioactivity of polysaccharides.