The structures of two polysaccharides from Lepidium meyenii and their immunomodulatory effects via activating NF-κB signaling pathway.

Lepidium meyenii Walp., also known as the "Peruvian national treasure", is a popular functional food in the daily lives of Peruvian people due to its bioactive with main polysaccharides. However, studies on polysaccharides isolated from Lepidium meyenii were few. Two new highly heterogeneous polysaccharides, MCP-1a and MCP-2b, were isolated and purified from the tuber of Lepidium meyenii. The structure characterization revealed that MCP-1a primarily consisted of D-Glc and had a molecular weight of 6.6 kDa. Its backbone was composed of 1,4,6-α-D-Glc, while branches feature T-α-L-Ara, 1,5-α-L-Ara, and T-α-D-Glc attached to the O-6 positions. MCP-2b was a rare arabinogalactan with a molecular weight of 49.4 kDa. Interestingly, the backbone of MCP-2b was composed of 1,6-ß-D-Gal, 1,3,6-ß-D-Gal with a few 1,3-ß-D-GlcpA-4-OMe units inserted. Side chains of MCP-2b were mainly composed of 1,3-ß-D-Gal, T-ß-D-Gal, T-α-L-Ara, 1,5-α-L-Ara, with trace amounts of 1,4-ß-D-Glc and T-ß-D-Glc. The bioactivity assay results revealed that MCP-1a and MCP-2b increased the release of NO, IL-1ß, TNF-α, and IL-6 from RAW 264.7 cells at concentrations ranging from 50 µg/mL to 400 µg/mL. Furthermore, MCP-1a and MCP-2b could promote the expression of key transcription factors (IκB-α, p-IκB-α, p65, and p-p65) in the NF-κB pathway, indicating that MCP-1a and MCP-2b had potential immunomodulatory activities.

Diagnostic Value of Carcinoembryonic Antigen Combined with Multi-Inflammatory Cell Ratios in Colorectal Cancer.

Purpose: To evaluate the diagnostic value of carcinoembryonic antigen (CEA) combined with inflammatory cell ratios in colorectal cancer (CRC). Methods: This retrospective study compared the data of CRC patients with healthy controls. The CEA levels were measured, and the neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (d-NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) were calculated. The receiver-operating characteristic (ROC) curve was used to assess the diagnostic value of each marker and combined detection. Spearman's rank correlation test was used to analyze the correlation between CEA and NLR, d-NLR, and PLR. Results: Inflammatory cell ratios and CEA were significantly higher in the CRC group. ROC curve analysis showed that NLR, d-NLR, and PLR had good diagnostic efficacy. The threshold showed that NLR, d-NLR, and PLR were all related to TNM stage, not to age, gender, tumor location, and degree of differentiation. CEA combined with NLR, d-NLR, and PLR (CNDNP) had a significant diagnostic value in CRC. Correlation studies showed that CEA was positively correlated with NLR and d-NLR but not with PLR. Conclusion: The combination of CEA with CNDNP might be a valuable indicator for CRC diagnosis.

Rheological properties of polysaccharides from Pholiota nameko with different temperature extraction: Concentration, pH, temperature, and saltion.

Cold and hot water extracted polysaccharides (CW-PNPs and HW-PNPs) were isolated from Pholiota nameko. The rheological properties of PNPs were investigated by steady shear and oscillatory rheological measurements. The PNPs exhibited typical non-Newtonian and shear-thinning behavior, which are affected by PNP concentration, temperature, pH value, salt ion, and concentration. Specifically, the apparent viscosity of the two PNPs solutions at concentration of 1% (w/w) was shown as HW-PNPs > CW-PNPs. The apparent viscosity of PNPs decreases under acidic and alkaline conditions and when the temperature rises; K+ and Na+ cause the apparent viscosity of CW-PNPs to decrease, while Ca2+ and Al3+ are opposite. The addition of four different salt ions all caused the apparent viscosity of the HW-PNPs to decrease. The results of dynamic rheological experiments show that G' and G″ showed slightly frequency dependency with G' exceeding G″ throughout the accessible range of frequency for CW-PNPs and HW-PNPs.

Toll-like receptor 4 gene polymorphisms rs4986790 and rs4986791 and age-related macular degeneration susceptibility: a meta-analysis.

Background: Several studies have investigated two single nucleotide polymorphisms (SNPs) (rs4986790 and rs4986791) of toll-like receptor 4 (TLR4) and age-related macular degeneration (AMD) susceptibility. However, their results varied. Here, we performed a systematic review and meta-analysis to investigate the association between these two SNPs and AMD susceptibility.Materials and Methods: We searched the PubMed and Web of Science databases for articles indexed up to July 20, 2019. Studies investigating the association between TLR4 polymorphisms rs4986790 (Asp299Gly) and rs4986791 (Thr399Ile) and AMD susceptibility were included in this systematic review. The results of the included studies were pooled with allele contrast, recessive, dominant and overdominant models. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Egger's test was used to evaluate publication bias.Results: Six studies with 9 cohorts were included in this systematic review and meta-analysis. The recessive and overdominant models showed that rs4986790 was significantly associated with AMD susceptibility, with odds ratios (ORs) of 0.73 and 1.41, respectively. By contrast, rs4986791 was not associated with AMD susceptibility. No publication bias was observed for either rs4986791 or rs4986790.Conclusion: The current evidence supports the hypothesis that rs4986790 but not rs4986791 is associated with AMD susceptibility.

Comparisons of the anti-tumor activity of polysaccharides from fermented mycelia and cultivated fruiting bodies of Cordyceps militaris in vitro.

A comparison of the anti-tumor activity of CMPS-II and CBPS-II polysaccharides, respectively is obtained from the fermented mycelium and cultivated fruiting bodies of Cordyceps militaris. This in vitro anti-tumor activity is investigated using an MTT assay, immunofluorescence staining, a Western Blot assay, a qRT-PCR assay, and Annexin V-FITC/PI double staining. The experimental results indicate that the inhibition rate of CMPS-II on H1299 tumor cells is higher than that of CBPS-II. With a concentration of 500 µâ€¯g/mL, the inhibition rate of CMPS-II and CBPS-II were 54.55% and 34.80%, respectively. Both CMPS-II and CBPS-II can increase the protein and mRNA expression level of cell apoptosis factors Caspase-3, Caspase-9, and p53, while reducing the protein and mRNA expression levels of proliferating cell nuclear antigen (PCNA), to induce tumor cells apoptosis. The induction effect of CMPS-II was stronger than CBPS-II. These results suggest that CMPS-II is superior to CBPS-II regarding the inhibition of H1299 lung cancer cells. Furthermore, CMPS-II is a potentially useful substitution for CBPS-II in the treatment of lung cancer and provides new insights into the mechanism of its anti-tumor activity.

The effect of fermentation conditions on the structure and anti-tumor activity of polysaccharides from Cordyceps gunnii.

This study investigates the effect of fermentation conditions on the structure and anti-tumor activity of intracellular polysaccharides (IPS) of Cordyceps gunnii (C. gunnii) in submerged fermentation. The environmental and nutritional conditions are determined in a shaker flask by a single factor test. The inhibition of IPS on S180 cells was as an optimization index. The results show that the optimal fermentation conditions of C. gunnii are an initial pH value of 6, a temperature of 25 °C, a rotation speed of 150 rpm, 4% glucose, and 1.0% peptone. Under these conditions, the macro molecular weight (M w) polysaccharide content and anti-tumor activity of IPS are significantly higher than that in the basal culture medium. GC, HPGPC, periodate oxidation-Smith degradation, NMR, and FT-IR determine the structural characteristics of CPS-JC and CPS-YH (pure IPS cultured in basal culture medium and optimal culture medium, respectively). The results indicate that CPS-JC is mainly composed of α-d-glucans, whereas CPS-YH primarily contain α-d-glucans with a trace amount of ß-d-glucans.

A new perspective for analyzing clinical characteristics of idiopathic retinal vasculitis, aneurysms, and neuroretinitis syndrome.

PURPOSE: We aimed to analyze the clinical characteristics of idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome. Furthermore, we aimed to correlate the number and location of retinal aneurysms with the size of retinal non-perfusion area and neovascularization. METHODS: Six patients with IRVAN syndrome (1 male and 5 females, age 5-38 years) were enrolled in this study. Fundus fluorescein angiography (FFA) was used to determine the total number of retinal aneurysms, number of aneurysms within the first branch of the retinal artery, minimum distance between the non-perfusion margin and the optic disc, and the number of retinal aneurysms in each quadrant, as well as the type of neovascularization. RESULTS: The size of the non-perfusion area was positively correlated with the total number of retinal aneurysms, the number of aneurysms within the first branch of the retinal artery, and the number of retinal aneurysms in each quadrant (P < 0.05). During the 5-year follow-up, one patient exhibited a dynamic change in the number and location of retinal aneurysms. CONCLUSIONS: In IRVAN syndrome, the number and location of retinal aneurysms correlate with the size of retinal non-perfusion area and type of neovascularization.

Association between the 8-oxoguanine DNA glycosylase gene Ser326Cys polymorphism and age-related cataract: a systematic review and meta-analysis.

PURPOSE: To investigate the association between the 8-oxoguanine DNA glycosylase (OGG1) gene Ser326Cys (rs1052133) polymorphism and age-related cataract (ARC). METHODS: MEDLINE and EMBASE were searched to identify potential studies published before May 19, 2017, investigating the association between the OGG1 gene Ser326Cys polymorphism and ARC risk. The quality of eligible studies was assessed using the Newcastle-Ottawa Scale tool. The association between the OGG1 gene Ser326Cys polymorphism and ARC was analyzed using meta-analysis. Publication bias and sensitivity analyses were also performed. RESULTS: Six studies were included in this systematic review, and five of these studies with Hardy-Weinberg equilibrium were included in a meta-analysis. The sample size of the meta-analysis was 3716, including 1831 patients with cataract and 1885 controls. Odds ratios (ORs) were 0.67 (95% confidence interval (CI) 0.52-0.85), 0.90 (95% CI 0.54-1.51), 0.52 (95% CI 0.32-0.85) and 0.72 (95% CI 0.56-0.92) for recessive, dominant, additive and allele contrast models, respectively. Sensitivity analysis indicated that the results of the meta-analysis were robust. No publication bias was observed. CONCLUSIONS: The OGG1 gene Ser326Cys polymorphism was associated with ARC risk.

Micropathogen Community Analysis in Hyalomma rufipes via High-Throughput Sequencing of Small RNAs.

Ticks are important vectors in the transmission of a broad range of micropathogens to vertebrates, including humans. Because of the role of ticks in disease transmission, identifying and characterizing the micropathogen profiles of tick populations have become increasingly important. The objective of this study was to survey the micropathogens of Hyalomma rufipes ticks. Illumina HiSeq2000 technology was utilized to perform deep sequencing of small RNAs (sRNAs) extracted from field-collected H. rufipes ticks in Gansu Province, China. The resultant sRNA library data revealed that the surveyed tick populations produced reads that were homologous to St. Croix River Virus (SCRV) sequences. We also observed many reads that were homologous to microbial and/or pathogenic isolates, including bacteria, protozoa, and fungi. As part of this analysis, a phylogenetic tree was constructed to display the relationships among the homologous sequences that were identified. The study offered a unique opportunity to gain insight into the micropathogens of H. rufipes ticks. The effective control of arthropod vectors in the future will require knowledge of the micropathogen composition of vectors harboring infectious agents. Understanding the ecological factors that regulate vector propagation in association with the prevalence and persistence of micropathogen lineages is also imperative. These interactions may affect the evolution of micropathogen lineages, especially if the micropathogens rely on the vector or host for dispersal. The sRNA deep-sequencing approach used in this analysis provides an intuitive method to survey micropathogen prevalence in ticks and other vector species.

[The correlation research on miRNA378* and calumenin,endoplasmic reticulum stress,apoptosis in suckling mouse myocardial cells infected with coxsackie virus B3].

OBJECTIVE: To investigate the effects of silencing miRNA378* on apoptosis, endoplasmic reticulum stress and calumenin of cardiomyocyte with coxsackie virus B3 (CVB3) infection. METHODS: Primary cultured suckling mouse myocardium were divided into control group (normal cell), coxsackie virus infection group (normal cell and coxsackie virus B3), miRNA378* control group (normal cell +coxsackie virus B3+miRNA378* empty plasmid), miRNA378* silencing plasmid group(normal cells + coxsackie virus B3 + miRNA378* silencing plasmid). Four groups of cells were transfected, infected and treated in CO2 incubator at 37℃. The α-SMA protein, cell apoptosis rate, calumenin, glucose regulated protein 78 (GRP78), activation transcription factor 6(ATF6) and transcription factors c/ebp homologue protein (CHOP) in endoplasmic reticulum were analyzed. RESULTS: By detecting α-SMA protein, the isolated suckling mouse ventricular myocardium were confirmed. TUNEL detection of different groups of ventricular cell apoptosis found that coxsackie virus group of ventricular myocytes apoptosis was significant. Compared with the coxsackie virus infection group of myocardial cells, miRNA378* silencing plasmid expression of cardiomyocyte apoptosis cells significantly reduced(P<0.01). The expressions of GRP78, ATF6 and CHOP were increased compared with those infected by Coxsackie virus infection (P<0.01), while the expressions of calumenin were decreased (P<0.01). CONCLUSIONS: CVB3 infected myocardial cells effected miRNA378* expression. It can trigger endoplasmic reticulum stress and activates signaling pathway factor and increase myocardial cell apoptosis.>.

[Effect of oxidative stress on myocardial apoptosis, endoplasmic reticulum stress and apoptosis factor in suckling mouse atria myocardium].

OBJECTIVE: To investigate the relationship between oxidative stress and myocardial apoptosis, endoplasmic reticulum stress, apoptosis-inducing factors in the process of by researching the effect of oxidative stress on myocardial apoptosis, endoplasmic reticulum stress and apoptosis factor--chop, bax, bcl-2 in suckling mouse atria myocardium. METHODS: The primary cultured suckling mouse myocardium were randomly divided into control group and oxidative stress group. Firstly, the suckling mouse atria cardiomyocytes were treated with H2O2 at the concentration of 100 m µmol/L for 2 hours. Then, the index of oxidative stress and anti-oxidative stress superoxide dismutase (SOD), the con-tents of malondialdehyde (MDA) and glutathione (GSH) of this two groups were detected by ELISA. Myocardial apoptosis of the two groups was detected by TUNEL. The expressions of glucose-regulated protein 78 (GRP78), glucose-regulated protein 94 (GRP94), C/EBP homolo-gous protein (chop), Bcl-2 associated X protein (bax), B-cell leukemia 2 protein (bcl-2) mRNA were detected by real time PCR. RESULTS: Compared with the control group, the viability of SOD and the contents of MDA in oxidative stress group were reduced, the contents of MDA was increased (P < 0.01). Compared with the control group, the expression of myocardial apoptosis in oxidative stress group was increased(P < 0.01); the expressions of GRP78, GRP94, chop and bax mRNA were increased, while the expression of bcl-2 mRNA was reduced in ox-idative stress group. CONCLUSIONS: Oxidative stress may induce the endoplasmic reticulum stress, activate the expressions of apoptosis factors, and finally increase the myocardial apoptosis of atria cardiomyocytes. This may connected to the incident of atrial fibrillation.

Effects of cultural medium on the formation and antitumor activity of polysaccharides by Cordyceps gunnii.

The effects of culture medium composition (i.e., carbon and nitrogen sources) on the growth of mycelia, molecular weight distribution and antitumor activity of intracellular polysaccharides (IPS) from Cordyceps gunnii were investigated. Sucrose and peptone were proved to be the best carbon and nitrogen sources for mycelia growth and remarkably improved IPS production. When the sucrose concentration was 2.0%, the mycelium yield reached up to 15.94±1.26 g/L, but with lower IPS yield; whereas the sucrose concentration was 4.5%, IPS yield reached to a maximum of 138.78±3.89 mg/100 mL. The effects of different carbon/nitrogen (C/N) ratios with equal amounts of carbon source matter on the mycelia and IPS formation were optimized. It found that the yield of mycelia and IPS were both reached to the highest at a C/N ratio of 10:3. In addition, the IPS had the highest macro molecular polysaccharide content and antitumor activity when sucrose concentration was 3.5% and the C/N ratio was 10:1.5. Thus, there was a positive correlation between molecular weight distribution and antitumor activity of IPS by C. gunnii.

Efficient synthesis and activity of beneficial intestinal flora of two lactulose-derived oligosaccharides.

Lactulose is considered as a prebiotic because it promotes the intestinal proliferation of Lactobacillus acidophilus which is added to various milk products. Moreover, lactulose is used in pharmaceuticals as a gentle laxative and to treat hyperammonemia. This study was aimed at the total synthesis of two Lactulose-derived oligosaccharides: one is 3-O-ß-d-galactopyranosyl-d-fructose, d-fructose and ß-d-galactose bounded together with ß-1,3-glycosidic bound, the other is 1-O-ß-d-galactopyranosyl-d-fructose, d-fructose and ß-d-galactose bounded together with ß-1,1-glycosidic bound, which were accomplished in seven steps from d-fructose and ß-d-galactose and every step of yield above 75%. This synthetic route provided a practical and effective synthetic strategy for galactooligosaccharides, starting from commercially available monosaccharides. Then we evaluated on their prebiotic properties in the search for potential agents of regulating and improving the intestinal flora of human. The result showed that the prebiotic properties of Lactulose-derived oligosaccharides was much better than Lactulose. Among them, 3-O-ß-d-galactopyranosyl-d-fructose displayed the most potent activity of proliferation of L. acidophilus.

Structural properties of polysaccharides from cultivated fruit bodies and mycelium of Cordyceps militaris.

The structural properties of polysaccharides, respectively, obtained from the fermented mycelium and cultivated fruiting bodies of the Cordyceps militaris were investigated and compared in this paper. First, the crude polysaccharides were extracted from the mycelium and the fruiting bodies, respectively. The polysaccharides were successively purified by Sevag and chromatography on Sephadex G-100 column to produce two polysaccharides fractions termed CMPS-II and CBPS-II, respectively. The average molecular weights of CMPS-II and CBPS-II were 1.402×10(3) kDa and 1.273×10(3) kDa, respectively, and they were mainly composed of mannose, glucose and galactose in the mole ratios of 1:28.63:1.41 and 1:12.41:0.74, respectively, for CMPS-II and CBPS-II. Afterward, the structural features of CMPS-II and CBPS-II were investigated by a combination of chemical and instrumental analysis, such as FT-IR, periodate oxidation-Smith degradation, GC-MS, NMR and methylation analysis. The results indicated that structurally, both CMPS-II and CBPS-II were 1,3-branched-galactomannoglucan that had a linear backbone of (1→4)-linked α-D-glucopyranose (Glcp). Congo-red test revealed that CMPS-II and CBPS-II existed as triple-helical chains in 0.05-0.15 M NaOH solution.

Structural characterization and anti-tumor activity of polysaccharide produced by Hirsutella sinensis.

HSP-III, a novel homogeneous polysaccharide with 513.89 kDa molecular weight, was fractionated from submerged cultures of Hirsutella sinensis by Sevag and chromatography on Sephadex G-100 column. The total sugar content of HSP-III was amounted to 89.87%. Based on the results of high performance gel permeation chromatogram (HPGPC), FT-IR, NMR spectroscopy, GC, periodate oxidation-smith degradation and methylation analysis, it showed that HSP-III was mainly composed of mannose and galactose, and a small amount of rhamnose, arabinose, xylose, and glucose. The molar ratio of Rha:Ara:Xyl:Man:Glu:Gal was 1.00:2.44:13.11:74.13:13.80:54.39. The main chain of HSP-III was majorly composed of (1→3) glucose. The tumor inhibition ratio on H22 cell was 79.04% at 100 µg/mL of HSP-III.

Influence of fermentation conditions on polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Cordyceps militaris.

The influence of different fermentation conditions on intracellular polysaccharide (IPS) production and activities of the phosphoglucomutase (PGM), UDPG-pyrophosphorylase (UGP), phosphoglucose isomerase (PGI), UDPG-dehydrogenase (UGD), and glucokinase (GK) implicated in metabolite synthesis in Cordyceps militaris was evaluated. The highest IPS production (327.57 ± 6.27 mg/100 mL) was obtained when the strain was grown in the optimal medium containing glucose (40 g · L(-1)), beef extract (10 g · L(-1)), and CaCO3 (0.5 g · L(-1)), and the initial pH and temperature were 7 and 25 °C, respectively. The activities of PGM, UGP, and PGI were proved to be influenced by the fermentation conditions. A strong correlation between the activities of these enzymes and the production of IPS was found. The transcription level of the pgm gene (encoding PGM) was 1.049 times and 1.467 times compared to the ugp gene and pgi gene (encoding UGP and PGI), respectively, in the optimal culture medium. This result indicated that PGM might be the highly key enzyme to regulate the biosynthesis of IPS of C. militaris in a liquid-submerged culture. Our study might be helpful for further research on the pathway of polysaccharide biosynthesis aimed to improve the IPS production of C. militaris.

[Influence of Nitrogen Flow Rate on the Structure and Luminescence Properties of Silicon-Rich Silicon Nitride Film Materials in a High Hydrogen Atmosphere].

High hydrogenated silicon-rich silicon nitride(SiNx∶H)thin films are deposited on the glass and monocrystalline silicon(110) substrates by plasma enhanced chemical vapor deposition using SiH4 and H2 as the main reaction gas with doping the N2. The ultraviolet-visible absorption spectrum, Fourier transform infrared absorption spectroscopy, Raman spectroscopy and photoluminescence spectrum are applied to characterize the changes of the band gap, the microstructure and related photoluminescence properties of the nitrogen-doped silicon film. It shows that hydrogen atoms can suppress the defects in the film and make film present silicon-rich under the low SiH4/H2 flow ratio, but they are not beneficial to the formation of silicon clusters in a hydrogen atmosphere. With the incorporation of nitrogen atoms, all the content of Si-N bonds, band gap and the degree of disorder in the microstructure of the films increase, films produce light emission related to the defect states. While the content of doped nitrogen atoms are further increased, it appears the band tail emission. Then the relationships between several light emissions and microstructure to be discussed. These results are useful for the optimization of light emission and microstructure for the silicon-rich silicon nitride film material prepared by PECVD.

Polymorphisms of DNA repair genes XPD (Lys751Gln) and XRCC1 (Arg399Gln), and the risk of age-related cataract: a meta-analysis.

PURPOSE: A meta-analysis of available studies was used to test the association between two DNA repair genes and age-related cataract. MATERIALS AND METHODS: A systematic search of the Chinese National Knowledge Infrastructure, EMBASE and PubMed databases identified six studies that were analyzed. Meta-analysis was used to evaluate single nucleotide polymorphisms (SNP) of the DNA repair gene xeroderma pigmentosum complementation group D (XPD) (Lys751Gln) and the X-ray repair cross-complementing gene 1 (XRCC1) (Arg399Gln). Only articles published before June 6, 2014, were included. The quality of the studies was determined using Newcastle-Ottawa Scale tools. The summary odds ratio (OR) and corresponding confidence interval (CI) for XPD Lys751Gln and XRCC1 Arg399Gln polymorphisms and risk of age-related cataract were estimated by random and fixed-effects models. Sensitivity analysis was employed to determine the robustness of the conclusions. RESULTS: Six studies, with a total of 1518 patients with cataractous lenses and 1437 subjects with clear lenses, were included in the meta-analysis. XRCC1 Arg399Gln polymorphisms were associated with cataract risk (recessive model: ORfixed = 0.79, 95% CI: 0.67-0.93; dominant model: ORfixed = 0.84, 95% CI: 0.64-1.11; additive model: ORfixed = 0.82, 95% CI: 0.72-0.92). Analysis of Chinese, but not non-Chinese subgroups, confirmed this association. The OR of XPD Lys751Gln polymorphisms for cataract was not significant. The associations remained significant after sensitivity analysis. CONCLUSIONS: This meta-analysis indicates that XRCC1 Arg399Gln polymorphisms, but not XPD Lys751Gln polymorphisms, are associated with risk of age-related cataract.

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.

Comparative evaluation of polysaccharides isolated from Astragalus, oyster mushroom, and yacon as inhibitors of α-glucosidase.

The incidence of diabetes has increased considerably, and become the third serious chronic disease following cancer and cardiovascular diseases. Though acarbose, metformin, and 1-deoxynojirimycin have good efficacy for clinical application as hypoglycemic drugs, their expensive costs and some degree of side effects have limited their clinical application. Recently, increasing attention has concentrated on the polysaccharides from natural plant and animal sources for diabetes. In order to illustrate the pharmaceutical activity of polysaccharides as natural hypoglycemic agents, polysaccharides isolated from Astragalus, oyster mushroom, and Yacon were evaluated for their inhibitory effects on α-glucosidase. Polysaccharides were extracted and purified from Astragalus, Oyster mushroom, and Yacon with hot water at 90 °C for 3 h, respectively. The total sugar content of the polysaccharide was determined by the phenol-sulfuric acid method. The α-glucosidase inhibitory activity was measured by the glucose oxidase method. The results exhibited that the inhibitory effects on α-glucosidase were in decreasing order, Astragalus > oyster mushroom > Yacon. The α-glucosidase inhibition percentage of Astragalus polysaccharide and oyster mushroom polysaccharide were over 40% at the polysaccharide concentration of 0.4 mg·mL(-1). The IC50 of Astragalus polysaccharide and oyster mushroom polysaccharide were 0.28 and 0.424 mg·mL(-1), respectively. The information obtained from this work is beneficial for the use polysaccharides as a dietary supplement for health foods and therapeutics for diabetes.