Physicochemical characterization, rheological properties, and hypolipidemic and antioxidant activities of compound polysaccharides in Chinese herbal medicines by fractional precipitation.

This study aimed to investigate the effects of different compound polysaccharides (CPs) extracted from Folium nelumbinis, Fructus crataegi, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos (w/w, 2:4:2:1:1.5:1) by gradient ethanol precipitation on the physicochemical properties and biological activities. Three CPs (CP50, CP70, and CP80) were obtained and comprised rhamnose, arabinose, xylose, mannose, glucose, and galactose in different proportions. The CPs contained different amounts of total sugar, uronic acid, and proteins. These also exhibited different physical properties, including particle size, molecular weight, microstructure, and apparent viscosity. Scavenging abilities of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 1,1'-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals of CP80 were more potent compared to those of the other two CPs. Furthermore, CP80 significantly increased serum levels of high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL), and hepatic lipase (HL) activity in the liver, while decreasing the serum levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), along with LPS activity. Therefore, CP80 may serve as a natural novel lipid regulator in the field of medicinal and functional food.

Structural characteristics of a low molecular weight velvet antler protein and the anti-tumor activity on S180 tumor-bearing mice.

Velvet antler is a traditional Chinese medicine with various pharmacological values, which is an important raw material for traditional Chinese medicinal wine. Nevertheless, the chemical compositions and bioactivities of velvet antler residue used for making medicinal wine are rarely reported, leading to a waste of resources. In this study, a velvet antler protein (VA-pro) was extracted from velvet antler residue by simulating the gastrointestinal digestion, and its composition, structural characteristics and in vivo anti-tumor activities were determined and investigated. VA-pro possessed high purity with a relatively low molecular weight as 22.589 kDa under HPLC, one- and two-dimensional electrophoresis, and it contained high contents of Pro, Gly, Glu and Ala. Besides, the secondary structure of VA-pro was dominated by ß-turn and ß-sheet, and VA-pro possessed similar protein sequence, isoelectric point and amino acid compositions to hypothetical protein G4228_020061. The in vivo results substantiated that VA-pro could improve the body weights and immune organ indices, increase the expressions of sera cytokines and regulate the distributions of T and B lymphocytes subsets in peripheral blood of S180 tumor-bearing mice. Furthermore, VA-pro could effectively inhibit solid S180 tumors growth by inducing S phase cell cycle arrest mediated through mitochondria. To summarize, our study provided theoretical support that VA-pro had the potential to be used as an immunopotentiator in immunocompromised or cancer-bearing hosts.

Structural Characterization of an Alcohol-Soluble Polysaccharide from Bletilla striata and Antitumor Activities in Vivo and in Vitro.

In general, Bletilla striata polysaccharides were mostly water-soluble. However, the structural property, immunomodulatory effects and antitumor activities of alcohol-soluble Bletilla striata polysaccharide were rarely reported. In this study, an alcohol-soluble Bletilla striata polysaccharide was firstly extracted, investigated the structural property and evaluated the antitumor activity in vivo and in vitro. Results showed that BSAP was a low molecular weight polysaccharide (2.29×104  Da) and consisted of glucose, xylose and mannose (molar ratio: 2.39 : 1.00 : 0.21). Animal experiments results suggested that BSAP could effectively inhibit the expansion of H22 solid tumors, protect thymus and spleen, improve macrophages, lymphocytes and NK cells activities and enhance lymphocyte subsets proportion, presenting a better immunological enhancement effect in vivo. Additionally, the results of cell experiments showed that BSAP had obvious antitumor effect in vitro, including inhibiting the proliferation of H22 cells and inducing the apoptosis of tumor cells. These results would provide theoretical basis and new ideas for the further development and utilization of BSAP in the biomedical field.

Novel Compound Polysaccharides from Chinese Herbal Medicines: Purification, Characterization, and Antioxidant Activities.

The present study investigated physicochemical properties and antioxidant activities in vivo and in vitro of purified compound polysaccharides (CPs-1) from Chinese herbal medicines, composed of lotus leaf, hawthorn, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos with the mass ratio of 2 : 4 : 2 : 1 : 1.5 : 1. The HPGPC profile and FT-IR spectra indicated that the average molecular weight of CPs-1 was 38.7 kDa and possessed the α- and ß-D-pyranose, respectively. The methylation analysis and NMR spectrum demonstrated that CPs-1 had a →6)-ß-D-Glcp-(1→6)-ß-D-Glcp(1→ backbone. Furthermore, the antioxidant assays in vitro revealed that CPs-1 displayed high scavenging abilities for DPPH, hydroxyl, and reducing power, as well as ABTS and superoxide scavenging capacity. The antioxidant experiments in vivo revealed that CPs-1 could significantly enhance CAT, SOD, and GSH-Px activities and dramatically reduce MDA levels in liver and serum of high-fat mice. Therefore, CPs-1 could be potentially incorporated into pharmaceutical products or functional foods as a natural antioxidant.

Synthesis of macromolecular Astragalus polysaccharide-nano selenium complex and the inhibitory effects on HepG2 cells.

In the present study, the previously obtained macromolecuar-weight Astragalus polysaccharide (average molecular weight of 1.61 × 106 Da) was used as a stabilizer and dispersing agent for nano-composites preparation by modifying selenium nanoparticles, and then the anti-hepatoma activity on HepG2 cells was investigated as well. Results showed that the nano-composites were obtained under polysaccharide concentration of 2 mg/mL and selenium/polysaccharide mass ratio of 1:15, and exhibited symmetrical spheroid with an average diameter of 62.3 nm, which has a good stability for 35 days at 4 °C. Furthermore, the in vitro anti-hepatoma experiments demonstrated that the composites could significantly inhibit the proliferation of HepG2 cells in a dose-dependent manner, and could induce the morphological changes, arrest the cell cycle in S phase, finally triggering HepG2 cells apoptosis through mitochondrial pathway. These data revealed that the composites had the potential to be a novel therapeutic drug or adjuvant for hepatoma-bearing patient treatments.

Antitumor activity and immunomodulation mechanism of a novel polysaccharide extracted from Polygala tenuifolia Willd. evaluated by S180 cells and S180 tumor-bearing mice.

We recently isolated a polysaccharide from Polygala tenuifolia Willd. (PTP) and reported that such a PTP could induce cell apoptosis with FAS/FAS-L-mediated death receptor pathway in human lung cancer cells. Herein, we indicate antitumor activity and immunoregulation of PTP for S180 sarcoma cells by in vitro and in vivo targeting. In vitro, S180 cells took on prominent characteristics of apoptosis under-treated with PTP in follow-up antitumor activity studies, including irregular shrinkage and fragmentation nuclear, apoptotic bodies formation, and reduction of mitochondrial membrane potential (MMP). Additionally, flow cytometry indicated that the number of normal cells (FITC-/PI-) gradually decreased from 98.08% to 16.31%, while the number of apoptotic cells (FITC+/PI- or FITC+/PI+) increased from 0.87% to 54.84%. The ratio of BAX and Bcl-2 increased, which promoted the release of Cytochrome C (CytC), and it further maximized the expression of activated-caspase-9/-3. Additionally, the PTP revised the immune organ indexes, the activities of NK cells and lymphocytes, and induced the secretion of IL-2 (7.34-16.17%), IFN-γ (14.34-20.85%) and TNF-α (12.32-22.58%) in vivo. Thus, PTP can induce cell apoptosis and activate the immunoregulation mechanism thereby exhibiting biological activity.

A Novel Optimization of Water-Soluble Compound Polysaccharides from Chinese Herbal Medicines by Quantitative Theory and Study on Its Characterization and Antioxidant Activities.

The present study optimized the extraction characterization and antioxidant activities of water-soluble compound polysaccharides (CPs) from hawthorn, lotus leaf, Fagopyrum tataricum, semen cassiae, Lycium barbarum, and Poria cocos Chinese herbal medicines that have mass ratios of 4 : 2 : 2 : 1.5 : 1 : 1. The CPs yield equation was predicted using quantitative theory, to which a maximum CPs yield of 7.18±0.24 % under the following optimal extraction conditions: a water-to-raw material ratio of 30 mL/g, an extraction temperature of 65 °C, an extraction time of 45 min, and extraction mode ultrasonic-assistant extraction. CPs were consisted of Ara, Gal, Glc, Xyl, Man, GalA and GlcA in a molar ratio of 3.1 : 2.6 : 50.6 : 1.7 : 20.4 : 17.2 : 4.2. The HPGPC profiles and FT-IR spectra implied that CPs were heterogeneous acidic polysaccharides and possessed the ß-d-pyranose configuration. Congo red test, CD spectrum and SEM revealed that CPs with three helix conformation showed a flocculent, granulous or sheet-like appearance. Furthermore, the relationships between antioxidant activity and concentration of CPs displayed significant positive correlation, and the scavenging abilities for DPPH, hydroxyl radical, ABTS, superoxide-anion radical and reducing power of CPs were 93.56±2.51 %, 84.03±1.69 %, 83.29±1.93 %, 37.49±1.93 % and 0.467±0.006 at a concentration of 4.0 mg/mL. Therefore, CPs could be applied as a potential natural antioxidant in pharmaceutical or functional food fields.

FAS/FAS-L-mediated apoptosis and autophagy of SPC-A-1 cells induced by water-soluble polysaccharide from Polygala tenuifolia.

In this study, a water-soluble polysaccharide was extracted from Polygonum tenuifolia to inhibit the proliferation of SPC-A-1 cells by the FAS/FAS-L-mediated pathway and autophagy. The molecular weight, composition, and structure of the Polygala tenuifolia polysaccharide (PTP) was detected by HPLC, HPAEC-PAD, NMR and FT-IR. The purified polysaccharide was composed of Ara, Gal, and Glc (molar ratio: 2.6:1.8:1.0) with α- and ß-configurations. Morphological changes were observed with microscopes, and the cell apoptosis-related markers detected by flow cytometry indicated that apoptosis and autophagy occurred in the SPC-A-1 cells. Western blot analysis showed that the expression of proteins was related to apoptosis and autophagy. The death receptor pathway demonstrated the up-regulated expression of FAS, ligand FAS-L, and FADD, which led to a cascade reaction of the caspase family that induced cell apoptosis. The up-regulation of LC 3B-II and the down-regulation of P62 indicated the occurrence of autophagy. In summary, these results showed that PTP can induce FAS/FAS-L-mediated apoptosis and autophagy in SPC-A-1 cells, and provide a strong theoretical basis for tumor prevention and clinical application of PTP in the future.

Relationship between heat treatment on structural properties and antitumor activity of the cold-water soluble polysaccharides from Grifola frondosa.

Grifola frondosa is a basidiomycete fungus with potential biomedical applications owing to the presence of bioactive polysaccharides. The activities of polysaccharides are influenced by many factors, particularly temperature; however, the optimal temperature and conditions for preparation of polysaccharides from this organism have not yet been determined. Therefore, in this study, cold-water soluble polysaccharides from Grifola frondosa were extracted at 4 °C (GFP-4) and purified. GFP-4-30, GFP-4-60 and GFP-4-90 were obtained from GFP-4 after treatment at 30 °C, 60 °C, or 90 °C, respectively, for 6 h. MTT results showed that GFP-4 had the highest inhibitory effects on the proliferation of SPC-A-1 cells in vitro. High-performance gel permeation chromatography results demonstrated that the molecular weight of GFP-4 was 1.05 × 106 Da and that GFP-4-30, GFP-4-60, and GFP-4-90 showed different levels of degradation and generated small molecule sugars. Fourier transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance results indicated that GFPs mainly consisted of α-D-Galp, α-D-Manp and α-D-Glcp. Periodate oxidation, Smith degradation, and methylation results showed that the backbones of the molecules consisted of 1,3-linked-Galp. After heat treatment, percentages of (1 → 3,4) α-D-Galp in heat-treated polysaccharides were obviously decreased, indicating their lower branching degree, and resulting in weaker antitumor effects. Overall, our findings demonstrated changes in the structure-activity relationships of GFP-4 after heat treatment and provided a theoretical basis for the application of GFP-4 in the food and drug industries.

Antitumor activity of selenium modification of the bovine milk component ß-Lg (Se-ß-Lg) on H22 cells.

In this study, the apoptosis induction and antitumor activity of a novel complex, seleno-ß-lactoglobulin (Se-ß-Lg), on H22 cells were explored. In in vitro experiments, the MTT assay showed that Se-ß-Lg was cytotoxic to H22 cells in a concentration- and time-dependent manner and displayed few proliferation inhibition effects on normal liver L02 cells. Annexin V-FITC/PI and PI staining assays showed that Se-ß-Lg induced apoptosis changes of H22 cells from early to late apoptosis and led to S phase cell cycle arrest. Western blot and Z-VAD-FMK inhibitor assays showed that Se-ß-Lg triggered the Fas/FasL-mediated caspase 8-dependent extrinsic death receptor pathway in H22 cells. In in vivo experiments, Se-ß-Lg effectively repressed the growth of transplanted H22 solid tumors in a dose-dependent manner and exhibited few toxic effects on the host animals. H&E and PI staining of tumor tissues showed that Se-ß-Lg caused the occurrence of typical apoptosis morphology features and dose-dependently increased the proportion of apoptosis peaks (Sub-G1 peak) in H22 solid tumors. These results suggest that Se-ß-Lg has the capacity to induce H22 tumor cell apoptosis in vitro and in vivo and support that Se-ß-Lg can be applied as a functional complex in food.

An Attempt of Using ß-Sitosterol-Corn Oil Oleogels to Improve Water Barrier Properties of Gelatin Film.

Oleogel with tailored viscoelasticity is a great interest for food structuring, while its potential benefits for edible film performance are not clear. In this study, ß-sitosterol (0, 5, 10, 15, and 20 wt%)-corn oil oleogel was developed and used in the formation of gelatin-based films. Importantly, adding oleogel significantly decreased water vapor permeability of the gelatin films, however, it had little negative influence on film strength. In addition, the results of this study demonstrated that increasing the sitosterol in oleogels led to an increasing number of ordered crystals formed in the oleogel, which contributed to compact and smooth surface of the film. Moreover, the incorporation of oleogel also caused some changes in molecule conformation and film barrier property. Therefore, the superior mechanical performance and moisture resistance properties of the film were obtained when 15% ß-sitosterol was used to prepare oleogel. PRACTICAL APPLICATION: Corn oil oleogels ß-sitosterol was incorporated with gelatin to prepare the gelatin film aiming to improve the water resistance of the films for its variety of practical production. The enhanced vapor permeability and accepted strength of the emulsion film indicated the potential application of it with a variety of edible packaging forms, such as films, pouch and sachet in medium and high humid condition.

Effects of Heat Treatment on the Structural Characteristics and Antitumor Activity of Polysaccharides from Grifola frondosa.

This study investigated the effects of heat treatment on structural characteristics and in vitro antitumor activity of polysaccharides from Grifola frondosa. GFP-4 (extracted at 4 °C), GFP-4-80 (80 °C treatment on GFP-4) and GFP-80 (extracted at 80 °C) were prepared, and the chemical composition analysis showed that their total sugar contents were all higher than 90%, high-performance gel-permeation chromatography (HPGPC), ion chromatography (IC) and Fourier-transform infrared spectroscopy (FTIR) results demonstrated that GFP-4 were degraded and denatured after 80 °C heat treatment, MTT and JC-1 results showed that GFP-4 exhibited higher inhibitory effects on HepG2 cells in vitro than GFP-4-80 and GFP-80. Our study suggested that heat treatment at 80 °C on polysaccharides from Grifola frondosa would destroy their structure and attenuate their antitumor effects.

Relationship between structural properties and antitumor activity of Astragalus polysaccharides extracted with different temperatures.

This study investigated the effects of different temperatures on structural characterization and antitumor activity of polysaccharides from Astragalus membranaceus. APS4 and APS90 were extracted at 4°C and 90°C, respectively, and purified by Sephadex G-200 column. APS4-90 were obtained from APS4 after treatment at 90°C for 6h. MTT results showed that APS4 possessed the highest inhibitory effects on MGC-803, A549 and HepG2 cells. HPGPC analysis showed that the average molecular weights of these polysaccharides were approximately 1.5×106Da, while the asymmetrical peak of APS4-90 suggested heat degradation and configuration changes of APS4. GC, NMR and methylation results showed that these three polysaccharides had similar monosaccharide components (mainly contain glucose), and their backbones were composed of (1→2)­α­d­Glcp. However, APS4 showed higher content of (1→2,6)­α­d­Glcp compared to APS4-90 and APS90, which indicated that higher branched degree would be responsible for the stronger in vitro antitumor activity in APS4. These results were also confirmed by specific rotation and SEM analysis. Our study suggested that APS4 had the potential application for cancer treatment.

Pinocembrin⁻Lecithin Complex: Characterization, Solubilization, and Antioxidant Activities.

Pinocembrin is a natural flavonoid compound which is capable of antioxidant, antibacterial, anti-inflammatory, and antineoplastic activities. The present study aimed to enhance the solubility and antioxidant activities of pinocembrin by complex formation with lecithin. The physicochemical characteristics of pinocembrin⁻lecithin complex were analyzed by ultraviolet (UV), fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and solubility assay, and the antioxidant activities of pinocembrin⁻lecithin complex were evaluated via radical scavenging capacities for 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl, and superoxide-anion. The results indicated that pinocembrin complex with lecithin could significantly improve the solubility of pinocembrin in water and n-octane, the pinocembrin⁻lecithin complex displayed no characteristic endothermic peak and the appearance of amorphous state, compared to the pinocembrin, and no new covalent bond was produced in the pinocembrin and lecithin compound. It was demonstrated that the antioxidant activities of pinocembrin were obviously enhanced by the complex with lecithin, and the scavenging capacities for hydroxyl radical, DPPH, superoxide-anion radical, and ABTS radical of pinocembrin⁻lecithin complex were 82.44 ± 2.21%, 40.07 ± 1.32%, 59.15 ± 0.86%, and 24.73 ± 1.04% at 1.0 mg/mL, respectively. It suggested that the pinocembrin⁻lecithin complex had a great potential application prospect in the healthcare industry and in clinical practice.

Characterization of Se-enriched Pleurotus ostreatus polysaccharides and their antioxidant effects in vitro.

Selenium-enriched polysaccharides have become a major research focus owing to their high anti-oxidant activities. Selenium-enriched Pleurotus ostreatus polysaccharide (Se-POP) and the native polysaccharide (POP) were obtained by hot water extraction from fresh fruiting bodies of P. ostreatus with or without selenium. Se-POP and POP had similar average molecular weights (0.95×104Da and 0.94×104Da, respectively). Se-POP was mainly composed of fucose, rhamnose, arabinose, galactose, glucose, and xylose, similar to the composition of POP, but in different molar ratios. In an FT-IR analysis, in comparison to POP, two new absorption peaks at 941cm-1 and 1048cm-1 were observed due to COSe and SeO bonds. In vitro study of DPPH, hydroxyl, and ABTS free radicals, Se-POP had a stronger antioxidant capacity than that of POP. Compared to POP, Se-POP had a superior ability to reduce hydrogen peroxide (H2O2)-induced oxidative stress and apoptosis in murine skeletal muscle (C2C12) cells. In general, selenium in Se-POP contributed to high antioxidant and biological activities. Se-POP acts as a potent antioxidant and has the ability to prevent oxidation via reactive oxygen species (ROS) and free radicals in humans. These results suggest that Se-POP is a candidate dietary supplement for functional foods.

Extraction of a Novel Cold-Water-Soluble Polysaccharide from Astragalus membranaceus and Its Antitumor and Immunological Activities.

The polysaccharides of Astragalus membranaceus have received extensive study and attention, but there have been few reports on the extraction of these polysaccharides using cold water (4 °C). In this study, we fractionated a novel cold-water-soluble polysaccharide (cAMPs-1A) from Astragalus membranaceus with a 92.00% carbohydrate content using a DEAE-cellulose 52 anion exchange column and a Sephadex G-100 column. Our UV, Fourier-transform infrared spectroscopy (FTIR), high-performance gel permeation chromatography, and ion chromatography analysis results indicated the monosaccharide composition of cAMPs-1A with 1.23 × 104 Da molecular weight to be fucose, arabinose, galactose, glucose, and xylose, with molar ratios of 0.01:0.06:0.20:1.00:0.06, respectively. The UV spectroscopy detected no protein and nucleic acid in cAMPs-1A. We used FTIR analysis to characterize the α-d-pyranoid configuration in cAMPs-1A. In addition, we performed animal experiments in vivo to evaluate the antitumor and immunomodulatory effects of cAMPs-1A. The results suggested that cAMPs-1A oral administration could significantly inhibit tumor growth with the inhibitory rate of 20.53%, 36.50% and 44.49%, respectively, at the dosage of 75,150, and 300 mg/kg. Moreover, cAMPs-1A treatment could also effectively protect the immune organs, promote macrophage pinocytosis, and improve the percentages of lymphocyte subsets in the peripheral blood of tumor-bearing mice. These findings demonstrate that the polysaccharide cAMPs-1A has an underlying application as natural antitumor agents.

ZBTB20 is required for anterior pituitary development and lactotrope specification.

The anterior pituitary harbours five distinct hormone-producing cell types, and their cellular differentiation is a highly regulated and coordinated process. Here we show that ZBTB20 is essential for anterior pituitary development and lactotrope specification in mice. In anterior pituitary, ZBTB20 is highly expressed by all the mature endocrine cell types, and to some less extent by somatolactotropes, the precursors of prolactin (PRL)-producing lactotropes. Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes. In ZBTB20-null mice, although lactotrope lineage commitment is normally initiated, somatolactotropes exhibit profound defects in lineage specification and expansion. Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ. In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro. In conclusion, our findings point to ZBTB20 as a critical regulator of anterior pituitary development and lactotrope specification.

Selenium modification of ß-lactoglobulin (ß-Lg) and its biological activity.

ß-Lg is a major whey protein in cow's milk. This study was aimed to find a new kind of organic selenium compound synthesized with ß-Lg and selenium dioxide as raw materials under the conditions of vacuum and low temperature. Fourier transformed infrared spectroscopy revealed that seleno-ß-lactoglobulin (Se-ß-Lg) displayed a strong band at 878cm(-1), belonging to SeO. Circular dichroism spectra results indicated that the conformation of Se-ß-Lg was transformed and α-helical, and unordered structures were increased by 9% and 11.2%, respectively, while ß-sheet and ß-turn were reduced by 14.2% and 6%, respectively. Electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry results showed that there were two protein bands (1-Seß-Lg and 2-Seß-Lg) in Se-ß-Lg, only one ß-Lg connected with selenate in 1-Seß-Lg, but two ß-Lgs, connected to each other, and with selenate, in 2-Seß-Lg. Morphological observation and hematoxylin and eosin staining indicated that Se-ß-lg could induce K562 cell apoptosis. These results indicated that Se-ß-Lg could be synthesized by selenium conjugating ß-Lg and it had antitumor activity.

Effect of ultrasonic treatment on structure and antitumor activity of mycelial polysaccharides from Cordyceps gunnii.

Taking mycelial polysaccharides from Cordyceps gunnii (C. gunnii) as the study subject, the effect of ultrasonic power, time and concentration of polysaccharides on antitumor activity of the polysaccharides was investigated. The ultrasonic processing condition of the polysaccharides was optimized by using orthogonal test design, and determined to be 400 W, 15 min and 1g/L. The change of structures of polysaccharides before and after ultrasonic treatment was also studied. Results show that ultrasonic treatment did not change the characteristic attribute of polysaccharides from C. gunnii. The composition of monosaccharide residues and the category of glycosidic bond have not been changed. But the molecular weight and intrinsic viscosity was reduced, and the alpha-helicity was enhanced after ultrasonic treatment. It was possible that ultrasonic treatment is an effective way for enhancing antitumor activity of polysaccharides.

Polysaccharides from Lycium barbarum leaves: isolation, characterization and splenocyte proliferation activity.

The polysaccharides from the fruits of Lycium barbarum have received considerable attention in previous publication, but the polysaccharides from the leaves were rarely reported. In the present work, four water-soluble polysaccharide fractions: LBP-I, LBP-II, LBP-III and LBP-IV isolated from L. barbarum leaves were purified through DEAE-Sephadex A-25. LBP-II and LBP-IV respectively showed one symmetrical peak on HPGPC with average molecular weight of 9.39 × 104 Da and 4.18 × 105 Da. UV and IR analysis of the two fractions showed the characteristics of acidic polysaccharides combined with polypeptides or proteins. GC analysis showed LBP-IV was mainly composed of rhamnose, arabinose, xylose, glucose and galactose with molar ratio of 1.61:3.82:3.44:7.54:1.00, and the uronic acid content was 47.68% (w/w) determined by sulfuric acid-carbazole method. ¹H and ¹³C NMR spectra of LBP-IV also showed the presence of carboxyl carbon and five anomeric carbons, and suggested there may be both α- and ß-anomeric configurations in this fraction. Moreover, splenocyte proliferation activity assay showed that LBP-IV significantly enhanced the proliferation of splenocyte stimulated by ConA or LPS, indicating the fraction has the beneficial effect on immunostimulating activity.