Polysaccharide biological response modifiers

Immunopotentiation and anti-tumor activity of carboxymethylated-sulfated beta-(1-->3)-d-glucan from Poria cocos

A carboxymethylated-sulfated derivative of (1-->3)-beta-d-glucan (PCS3-II) extracted from Poria cocos was synthesized and coded as CS-PCS3-II. Results of infrared (IR) and Carbon-13 nuclear magnetic resonance spectroscopy ((13)C NMR) indicated that CS-PCS3-II contained carboxymethyl and sulfate groups with a degree of substitution (DS) of 1.05 and 0.36 respectively. By using size exclusion chromatography (SEC) combined with laser light scatting (LLS), the dependence of radius of gyration (<S(2)>(z)(1/2)) on the molecular weight (M(w)) for CS-PCS3-II was established as <S(2)>(z)(1/2) = 6.92 x 10(-2)M(w)(0.59) in 0.15M NaCl solution at 25 degrees C, suggesting that CS-PCS3-II existed as an extended flexible chain. CS-PCS3-II exhibited significantly higher inhibition ratio to Sarcoma 180 tumor in BALB/c mice than PCS3-II. Histological examination of tumor cells treated with CS-PCS3-II had signs of necrosis and apoptosis. It is postulated that introduction of the carboxymethyl and sulfate groups to PCS3-II increased its possible contact with the receptors of immune cells through hydrogen binding and electrostatic attraction, leading to a stronger immunological responses that resulted in inhibition of tumor cell proliferation. Moreover, there were significant increases in phagocyte and thymus indexes, spleen index, hemolytic activity as well as spleen antibody production and delayed type hypersensitivity (DTH), suggesting that CS-PCS3-II could significantly enhance immunpotentiation in mice.

Plant-derived polysaccharide supplements inhibit dextran sulfate sodium-induced colitis in the rat

Several plant-derived polysaccharides have been shown to have anti-inflammatory activity in animal models. Ambrotose complex and Advanced Ambrotose are dietary supplements that include aloe vera gel, arabinogalactan, fucoidan, and rice starch, all of which have shown such activity. This study was designed to evaluate these formulations against dextran sulfate sodium (DSS)-induced colitis in rats and to confirm their short-term safety after 14 days of daily dosing. Rats were dosed daily orally with vehicle, Ambrotose or Advanced Ambrotose. On day six groups of rats received tap water or 5% Dextran Sulfate sodium. Ambrotose and Advanced Ambrotose significantly lowered the disease scores and partially prevented the shortening of colon length. An increase in monocyte count was induced by dextran sulfate sodium and inhibited by Ambrotose and Advanced Ambrotose. There were no observable adverse effects after 14-day daily doses. The mechanism of action of the formulations against DSS-induced colitis may be related to its effect on monocyte count.

Lycium barbarum polysaccharide inhibits the infectivity of Newcastle disease virus to chicken embryo fibroblast

Lycium barbarum polysaccharide (LBPS) was extracted by water decoction and ethanol precipitation. After purification, four sulfated lycium barbarum polysaccharides (sLBPSs), sLBPS(0.7), sLBPS(1.1), sLBPS(1.5) and sLBPS(1.9), were prepared by chlorosulfonic acid-pyridine method respectively at four designed modification conditions. Four sLBPSs at 5 concentrations, within the safety concentration scope, and Newcastle disease virus (NDV) were added into cultivating system of chick embryo fibroblast (CEF) respectively in three modes, pre- and post-adding polysaccharide and simultaneous adding polysaccharide and virus after being mixed. The effects of sLBPSs on cellular infectivity of NDV were assayed by MTT method taking the non-modified LBPS as control. The results showed that sLBPS(1.5), sLBPS(1.9) and sLBPS(1.1) in three sample-adding modes, sLBPS(0.7) in simultaneous adding after being mixed could significantly inhibit the infectivity of NDV to CEF. The viral inhibitory rate of sLBPS(1.5) in pre- and simultaneous adding and sLBPS(1.9) in post-adding was the highest. Non-modified LBPS did not present significant effect in any sample-adding mode. These results indicated that sulfated modification could significantly enhance the antiviral activity of LBPS, which was correlated with the degree of sulfation (DS) of sLBPS. sLBPS(1.5) and sLBPS(1.9) possessed better activity and would be as the compositions of antiviral prescription.

Activation of macrophages by polysaccharide-protein complex from Lycium barbarum L

Macrophages play crucial roles in innate immunity. This paper reports that a polysaccharide-protein complex isolated from Lycium barbarum (LBP) is able to activate macrophages. LBP was isolated from Lycium barbarum fruit and separated to five homogenous fractions, designated LBPF1, LBPF2, LBPF3, LBPF4 and LBPF5. It was found that LBP (50 mg/kg, i.p.) markedly upregulated the expressions of CD40, CD80, CD86 and MHC class II molecules on peritoneal macrophages. In vitro studies showed that LBP and LBPF1-5 activated transcription factors NF-kappaB and AP-1 by RAW264.7 macrophage cells, induced TNF-alpha, IL-1beta, IL-12p40 mRNA expression, and enhanced TNF-alpha production in a dose-dependent manner. Furthermore, LBP (50 mg/kg, i.p.) significantly enhanced macrophage endocytic and phagocytic capacities in vivo. These results indicate that LBP enhances innate immunity by activating macrophages. The mechanism may be through activation of transcription factors NF-kappaB and AP-1 to induce TNF-alpha production and upregulation of MHC class II costimulatory molecules.

Isolation and characterization of extracellular polymeric substances from micro-algae Dunaliellasalina under salt stress

Extracellular polymeric substances (EPSs), produced by Dunaliella salina strain, increase concomitantly with salt concentration and maximum (944 mg/l) were obtained at 5M NaCl, whereas minimum (56 mg/l) at 0.5M salinity. Emulsifying activity was measured in terms of strength to retain the emulsion and comparatively 85.76% retention was observed at 0.5M salinity thereafter it intends to decline. The FT-IR-spectra reveal characteristic functional groups NH stretching, asymmetrical CH stretching vibration of aliphatic CH(2)-group, CC stretching of aromatic, CN stretch of aliphatic amine, NH wag of primary amine and CX stretch of alkyl-halides with a stretching of COC, CO corresponding to the presence of carbohydrates. The FT-IR-spectra substantiated the presence of primary amine-group, aromatic-compound, halide-group, aliphatic alkyl-group and polysaccharides. Four monosaccharides (glucose, galactose, fructose and xylose) were also detected by HPLC analysis. Production of EPSs may allow further exploration of D. salina as potential EPSs producer and make it as a promising candidate for biotechnological and industrial exploitation.

Solution structure of the silkworm betaGRP/GNBP3 N-terminal domain reveals the mechanism for beta-1,3-glucan-specific recognition

The beta-1,3-glucan recognition protein (betaGRP)/Gram-negative bacteria-binding protein 3 (GNBP3) is a crucial pattern-recognition receptor that specifically binds beta-1,3-glucan, a component of fungal cell walls. It evokes innate immunity against fungi through activation of the prophenoloxidase (proPO) cascade and Toll pathway in invertebrates. The betaGRP consists of an N-terminal beta-1,3-glucan-recognition domain and a C-terminal glucanase-like domain, with the former reported to be responsible for the proPO cascade activation. This report shows the solution structure of the N-terminal beta-1,3-glucan recognition domain of silkworm betaGRP. Although the N-terminal domain of betaGRP has a beta-sandwich fold, often seen in carbohydrate-binding modules, both NMR titration experiments and mutational analysis showed that betaGRP has a binding mechanism which is distinct from those observed in previously reported carbohydarate-binding domains. Our results suggest that betaGRP is a beta-1,3-glucan-recognition protein that specifically recognizes a triple-helical structure of beta-1,3-glucan.

Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose

Botryosphaeran (EPS(FRU)), an exopolysaccharide of the beta-(1-->3,1-->6)-d-glucan type with 31% branching at C-6, is produced by the fungus Botryosphaeria rhodina MAMB-05 when grown on fructose as carbon source. Botryosphaeran was derivatized by sulfonation to induce anticoagulant activity. The effectiveness of the sulfonation reaction by chlorosulfonic acid in pyridine was monitored by the degree of substitution and FT-IR analysis of the sulfonated EPS(FRU) (once sulfonated, EPS(FRUSULF); and re-sulfonated, EPS(FRURESULF)). Activated partial thromboplastin time (APTT) and thrombin time (TT) tests of EPS(FRURESULF) indicated significant in vitro anticoagulant activity that was dose-dependent. EPS(FRU) did not inhibit any of the coagulation tests.

Preparation of the different derivatives of the low-molecular-weight porphyran from Porphyra haitanensis and their antioxidant activities in vitro

Porphyran extracted from Porphyra haitanensis is a sulfated polysaccharide, which possesses excellent antioxidant activities. In this study, we prepared one low-molecular-weight porphyran and its sulfated, acetylated, phosphorylated and benzoylated derivatives. Their antioxidant activities were investigated including scavenging effect of superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals. The results of chemical analysis and FT-IR spectrums showed the modification was successful. And in addition, we found that certain derivative exhibited stronger antioxidant activity than low-molecular-weight porphyran. The benzoylated derivative showed the most excellent antioxidant activity in three assays, so this derivative needs to be attended to.

New method development for nanoparticle extraction of water-soluble beta-(1-->3)-D-glucan from edible mushrooms, Sparassis crispa and Phellinus linteus

Sparassis crispa and Phellinus linteus are edible/medicinal mushrooms that have remarkably high contents of beta-(1-->3)-D-glucan, which acts as a biological response modifier, but difficulty in cultivating the fruiting bodies and extraction of beta-D-glucan have restricted detailed studies. Therefore, a novel process for nanoparticle extraction of Sparan, the beta-D-glucan from Sparassis crispa, and Phellin, the beta-D-glucan from Phellinus linteus, has been investigated using insoluble tungsten carbide as a model for nanoknife technology. This is the first report showing that the nanoknife method results in high yields of Sparan (70.2%) and Phellin (65.2%) with an average particle size of 150 and 390 nm, respectively. The extracted Sparan with beta-(1-->3) linkages showed a remarkably high water solubility of 90% even after 10 min of incubation at room temperature. Therefore, it is likely that this nanoknife method could be used to produce beta-D-glucan for food, cosmetic, and pharmaceutical industries.

Preparation, characterization and immunomodulatory activity of selenium-enriched exopolysaccharide produced by bacterium Enterobacter cloacae Z0206

The tolerant-selenium exopolysaccharide-producing bacterial strain Enterobacter cloacae Z0206 was batch cultured in PDA medium containing optimal concentration of sodium selenite. Selenium was accumulated efficiently in Enterobacter cloacae Z0206 during cultivation with selenium. Inorganic selenite could be transformed into organic forms. Selenium-enriched exopolysaccharide (Se-ECZ-EPS-1) was purified from the fermentation liquid. Selenium content of Se-ECZ-EPS-1 was 12.962microg/g. Se-ECZ-EPS-1 with Mw of 29,300Ka was composed of Glc, Gal and Mann with molar ratio of 8.530:0.061:0.706. Administration of Se-ECZ-EPS-1 to cyclophosphamide (CP)-exposed animals resulted in improvement of cellular and humoral immune responses. These findings indicated that Se-ECZ-EPS-1 may act as potent immunomodulatory agents.

Isolation and partial characterisation of four novel plasma lectins from the American lobster Homarus americanus

Although numerous haemolymph-derived crustacean lectins are described, few have been reported for the American lobster Homarus americanus. In the present study, affinity chromatography was used to isolate and partially describe the carbohydrate affinity of four new lectins from H. americanus plasma. HaMBP and HaDNABP were homodimers of approximately 30 kDa subunits which bound to mannan- and DNA-agarose columns, respectively. These proteins had partially overlapping elution profiles, and both shared and unique amino acid sequences and fragmentation patterns after trypsin digestion. A third homodimer of approximately 29 kDa subunits eluted with HaMBP and HaDNABP under certain conditions. HaNBP occurred as a monomer and dimer of approximately 40 kDa subunits and was recovered in relatively large quantities from mannan-agarose with N-acetylated sugars. Transmission electron microscopy revealed HaNBP to be a linear protein composed of multiple globular subunits.

Toxicological evaluation of fucoidan from Cladosiphon okamuranus

Fucoidans are sulfated polysaccharides extracted from brown seaweeds. They have a wide spectrum of activity in biological systems. Besides their well-known anticoagulant and anti-thrombotic activity, fucoidans modulate inflammation, possess antiproliferative and anti-adhesive effects on cells, protect cells from viral infection, and interfere with mammalian fertilization. Fucoidans are now used as raw material for development of drugs and are also widely used as a health-promoting food component. However, studies on the toxicity of fucoidans from different brown algae are limited. The present study examined the acute toxicity of varying levels of fucoidan extracted from Okinawa mozuku, a brown alga (Cladosiphon okamuranus), in Wistar rats after oral administration. No significant toxicological changes were induced by fucoidan at a dose of 600 mg/kg of body weight/day. However, with concentrations at and above 1,200 mg/kg of body weight/day, clotting time was significantly prolonged. No other signs of toxicity were observed.

Structural stability of Sclerotium rolfsii ATCC 201126 beta-glucan with fermentation time: a chemical, infrared spectroscopic and enzymatic approach

AIMS

Sclerotium rolfsii ATCC 201126 exopolysaccharides (EPSs) recovered at 48 h (EPS I) and 72 h (EPS II) of fermentation, with differences in rheological parameters, hydrogel topography, salt tolerance, antisyneresis, emulsifying and suspending properties, were subjected to a polyphasic characterization in order to detect structural divergences.

METHODS AND RESULTS

Fermenter-scale production led to productivity (P(r)) and yield (Y(P/C)) values higher at 48 h (P(r) = 0.542 g l(-1) h(-1); Y(P/C) = 0.74) than at 72 h (P(r) = 0.336 g l(-1) h(-1); Y(P/C) = 0.50). Both EPSs were neutral glucose-homopolysaccharides with a beta-(1,3)-glycosidic backbone and single beta-(1,6)-glucopyranosyl sidechains regularly attached every three residues in the main chain, as revealed by chemical analyses. The infra-red diagnostic peak at 890 cm(-1) confirmed beta-glycosidic linkages, while gentiobiose released by beta-(1,3)-glucanases confirmed single beta-1,6-glycosidic branching for both EPSs.

CONCLUSIONS

The true modular repeating unit of S. rolfsii ATCC 201126 scleroglucan could be resolved. Structural stability was corroborated and no structural differences could be detected as to account for the variations in EPSs behaviour.

SIGNIFICANCE AND IMPACT OF THE STUDY

Recovery of S. rolfsii ATCC 201126 scleroglucan at 48 h might be considered based on better fermentation kinetic parameters and no detrimental effects on EPS structural features.

Preliminary studies on the chemical characterization and antioxidant properties of acidic polysaccharides from Sargassum fusiforme

In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S. fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and beta-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content.

The analysis of Radix Angelicae Sinensis (Danggui)

Radix Angelicae Sinensis, known as Danggui in China, is one of the most popular traditional Chinese medicines (TCMs), which is contained by more than 80 composite formulae. Modern researches indicate that phthalides, organic acids and their esters, polysaccharides are main chemical components related to the bioactivities and pharmacological properties of Danggui. Some of them, such as Z-ligustilide and ferulic acid, are selected as marker compounds to evaluate the quality of Danggui frequently. Because of the diversity of chemical structures and characters of these components, analytical methods of Danggui are various, including GC-MS, HPLC-DAD-MS, TLC, CE-DAD, and so on. Besides that, the development of analytical technology makes the quality control of Danggui more effective and reliable. Quality evaluation is from single or several components' analysis to fingerprinting, or in combination. Furthermore, bioactive components screening of Danggui has also attracted much attention, which will help us evaluate the selected marker components to some extent. In this paper, the literatures about the major phytoconstituents of Danggui, quality control and bioactive components screening methods have been reviewed. Main attention is given to the different methodologies developed to perform chemical analysis, including separation, detection and identification.

Higher order structure of (1,3)-beta-D-glucans and its influence on their biological activities and complexation abilities

(1,3)-beta-D-Glucans form a group of biologically active biopolymers that exist in different structural organizations depending on the environmental conditions. The biological effect of (1,3)-beta-D-glucans is a core issue stimulating large research efforts of the molecular properties and their consequences for action as biological response modifiers. The fascination for these molecules increased further following the finding of their ability to form complexes of defined geometry with a number of structures, ranging from linear architectures as polymers or carbon nanotubes, to globular structures as gold particles or dye molecules. The fascinating information concerning the relationship between sample treatment history and molecular organization has not yet reached out to all the contributors within the field, resulting in unnecessary apparent inconsistencies in the literature. In addition to environmental conditions, the sample history is known to influence on the precise structural organization of these molecules. The present knowledge related to the structure of native as well as denatured, renatured and annealed (1,3)-beta-D-glucans is reviewed. The influence of their structural organization on the biological activity and complexation abilities is discussed, and some factors hindering progress in the understanding of their biological effects or complexation abilities are pointed out.

Physiological activities of a beta-glucan produced by Panebacillus polymyxa

In vitro bioactivities of a beta-glucan produced by Panebacillus polymyxa JB115 were investigated. Nitric oxide production by RAW 264.7 macrophage cells pre-treated with beta-glucan JB115 (from 0.1 to 1 mg ml(-1)) was significantly increased, compared to that in untreated cells (P < 0.001). The beta-glucan JB115 increased superoxide radical-scavenging activity by 66% at 1 mg ml(-1). It also suppressed hyaluronidase (32%) and collagenase (33%) activities and, additionally, displayed antitumor activity, blocking the growth of Sarcoma 180 cells in a concentration-dependent manner. The immune-stimulatory, antioxidant, collagenase inhibitory and hyaluronidase inhibitory effects of the beta-glucan support its potential role in the prevention of bacterial disease against fish and in the protection of skin against aging.

Chemical and immunological modifications of an arabinogalactan present in tea preparations of Phyllanthus niruri after treatment with gastric fluid

An arabinogalactan (AG) obtained from tea preparations of Phyllanthus niruri was previously investigated and presented immunological properties when tested with peritoneal mice macrophages. AG was now submitted to acidic and neutral gastric conditions using human gastric fluids and aq. HCl solution. Since the acidic procedures gave rise to the same free monosaccharidic composition, the acid hydrolyzate of AG at pH 2.00 was treated with ethanol to form insoluble (AG-P) and soluble fractions (AG-S). These were analyzed using (13)C NMR, HPSEC, and GC-MS for monosaccharide composition and methylation analyses. The results showed an intense partial degradation, including cleavages of the main chain. AG-S presented the monosaccharides released from the native polymer and some oligosaccharides as shown by methylation data. AG-P contained larger molecular fragments comprising the internal units from AG, which were not attacked by the hydrolysis condition. Both fractions were tested in peritoneal mice macrophages and remained active, promoting an increase of superoxide anion production of 2.0 and 2.3-fold, at 250 microg/mL, for AG-S and AG-P, respectively. When compared to AG, a slight diminished response was observed, revealing a structure-activity relation. The significance of the results is that most plant extracts are orally ingested and will reach the gastrointestinal tract before performing a biological function, so checking these changes is crucial to propose future clinical therapies based on the rational use of phytomedicine.

The renal effects of alginates isolated from brown seaweed Sargassum vulgare

Alginates isolated from Sargassum vulgare, present a strong antitumor activity, associated with kidney reversible damage, as analysed by histopathology of treated animals. In the present study, the renal alteration mechanisms of S. vulgare alginates were investigated using the isolated perfused rat kidney and the isolated perfused rat mesenteric blood vessel methods. The results showed that the effects of Sargassum vulgare low viscosity (SVLV) alginate were more potent than those of Sargassum vulgare high viscosity (SVHV) alginate in the isolated rat kidney. The SVLV alginate caused considerable changes in renal physiology, as shown by an increase in parameters such as perfusion pressure, renal vascular resistance, glomerular filtration rate, urinary flow and sodium, potassium and chloride excretion and by reduction of chloride tubular transport. The effects of SVHV were weaker than those of SVLV. The effects of SVLV on kidney could be related to direct vascular action as demonstrated with SVLV alginate on mesenteric blood vessels. In conclusion, the Sargassum vulgare alginate altered the renal function parameters evaluated. S. vulgare low viscosity alginate renal effects were more potent than S. vulgare high viscosity alginate. It is suggested that physicochemical differences between SVHV and SVLV could explain the differences found in the results.

Aloin induces apoptosis in Jurkat cells

Aloe is widely used as a dietary supplement. However, there are continuing concerns over the toxicity and the purity of aloe-based products. The primary class of compounds responsible for aloe-induced toxicity are anthraquinones. One of these, aloe-emodin, has been extensively investigated for apoptosis inducing effects. Conversely, the precursor to aloe-emodin, aloin, has been subjected to only minimal investigation of any cytotoxic effects. Jurkat T cells, an established model for the study of compound toxicity, were used to evaluate the effect of aloin on cell viability. Cells were analyzed using flow cytometry and microscopy for cell size and granularity, cell membrane integrity, mitochondrial membrane potential, and cell cycle profile. Treatment with aloin resulted in a reduction in cell size, compromised membrane integrity, and loss of mitochondrial membrane potential in a dose-dependent manner. Additionally, treatment with aloin resulted in alteration of the cell cycle, specifically a block at G2/M phase. Importantly, the loss of cell membrane integrity was preceded by a loss of mitochondrial membrane potential, suggesting a mitochondrial-dependent pathway for aloin-induced apoptosis. These observations provide insight into the potential mechanisms of aloin-induced toxicity and thus, perhaps, aloe preparation-induced toxicity. Furthermore, because of the concern over the safety of aloe-based supplements, this work suggests that aloe supplements not containing aloin may be safer than aloe supplements containing aloin, and that aloin should be considered in addition to concentrations of aloe-emodin.

In vitro and in vivo immunomodulating and immunorestorative effects of Astragalus membranaceus

Astragalus membranaceus is a common traditional Chinese medicinal plant widely used as a tonic to enhance the body's natural defense mechanisms. In this study, bioactive fractions were isolated from the roots of Astragalus membranaceus. One of these fractions, designated as AI, was found to be the most potent with respect to its mitogenicity on murine splenocytes. Effects of AI on both specific and nonspecific immunity in mouse models were examined. Results showed that AI could exhibit mitogenic and co-mitogenic activities on mouse splenocytes, both in vitro and in vivo. Experiments in human cell culture demonstrated that AI was also active on human lymphocytes. It was found that AI was mitogenic to T cell depleted population but virtually inactive on B cell depleted population. Intraperitoneal injection of AI into mice markedly augmented the antibody response to sheep red blood cells. Besides, both the influx of macrophages into the peritoneal cavity and the phagocytic activity of macrophages were found to be enhanced by AI in vivo. On the other hand, AI could significantly increase the interleukin-2 receptor expression on mouse splenocytes in vitro. In terms of immunorestorative activity, it was found that AI could restore the lymphocyte blastogenic response of the older mice to values that are normally found in the younger mice. Moreover, administration of AI in vivo could partially restore the depressed immune functions in tumour-bearing mice and cyclophosphamide-treated mice. Collectively, the results clearly showed that AI could exhibit immunomodulating and immunorestorative effects, both in vitro and in vivo.

New polysaccharide from Nerium indicum protects neurons via stress kinase signaling pathway

Most of the polysaccharides purified from Chinese medicinal herbs showed anti-tumor and immune-stimulating effects. However, little is known about their effects on neuroprotection. Our previous study has demonstrated that polysaccharides (J2, J3 and J4) isolated from the flowers of Nerium indicum (Oleander) exert partial protection in cortical neurons stressed by beta-amyloid (Abeta) peptides or deprivation of nutrition from serum. In this study, we have isolated and characterized a new polysaccharide from the flowers of N. indicum (named as J6) and aimed to investigate its neuroprotective effects against Abeta-induced apoptosis. Pretreatment of the polysaccharide J6 significantly decreased the activity of caspase-3 as well as the cytotoxicity triggered by Abeta peptides in a dose-dependent manner. In contrast to the activation of survival signaling such as Akt found in J2, J3 and J4 fractions, neuroprotective effects of J6 markedly inhibited Abeta peptide-stimulated phosphorylation of c-Jun N-terminal kinase (JNK-1) as determined by Western blot analysis. Taken together, the polysaccharide J6 isolated from the flowers of N. indicum can serve as potential neuroprotective agent against neuronal death in Alzheimer's disease and the neuroprotective mechanism may primarily rely on inactivation of JNK signaling pathway.

Angelan isolated from Angelica gigas Nakai induces dendritic cell maturation through toll-like receptor 4

During the evolution of neoplastic diseases, dendritic cell (DC) functions are usually attenuated, and this presents a problem to DC-based immunotherapies against cancer. Here, we investigated the effects of angelan, an acidic polysaccharide isolated from Angelica gigas Nakai, on DC maturation. Angelan efficiently increased the maturation of tlr4(+/+) DCs from C57BL/6 and C3H/HeN mice, but not tlr4(-/-) DCs from C3H/HeJ mice. Phenotypic maturation was confirmed by the elevated expressions of CD80, CD86, and MHC-class II molecules, and functional maturation by increased IL-12 production, enhanced allogenic T cell stimulation, and decreased endocytosis. Angelan was found to activate ERK and NF-kappaB, which are signaling molecules down-stream of toll-like receptor-4 (TLR4) receptors. Angelan-treated mature DC more effectively inhibited B16F10 tumor growth than immature DCs in syngenic murine tumor model. These results indicate that angelan induces DC maturation via TLR4 signaling pathways and suggest the possible use of angelan in DC-based immunotherapies.