Flavonoid substituted polysaccharides from Tamarix chinensis Lour. alleviate H1N1-induced acute lung injury via inhibiting complement system.

ETHNOPHARMACOLOGICAL RELEVANCE: Viral pneumonia is a highly pathogenic respiratory infectious disease associated with excessive activation of the complement system. Our previous studies found that the anticomplement polysaccharides from some medicinal plants could significantly alleviate H1N1-induced acute lung injury (H1N1-ALI). The leaves and twigs of Tamarix chinensis Lour. are traditionally used as a Chinese medicine Xiheliu for treating inflammatory disorders. Interestingly, its crude polysaccharides (MBAP90) showed potent anticomplement activity in vitro. AIM OF THE STUDY: To evaluate the therapeutic effects and possible mechanism of MBAP90 on viral pneumonia and further isolate and characterize the key active substance of MBAP90. MATERIALS AND METHODS: The protective effects of MBAP90 were evaluated by survival tests and pharmacodynamic experiments on H1N1-ALI mice. Histopathological changes, viral load, inflammatory markers, and complement deposition in lungs were analyzed by H&E staining, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC), respectively. An anticomplement homogenous polysaccharide (MBAP-3) was obtained from MBAP90 by bio-guided separation, and its structure was further characterized by methylation analysis and NMR spectroscopy. RESULTS: Oral administration of MBAP90 at a dose of 400 mg/kg significantly increased the survival rate of mice infected with the lethal H1N1 virus. In H1N1-induced ALI, mice treated with MBAP90 (200 and 400 mg/kg) could decrease the lung index, lung pathological injury, the levels of excessive proinflammatory cytokines (IL-6, TNF-α, MCP-1, IL-18, and IL-1ß), and complement levels (C3c and C5b-9). In addition, MBAP-3 was characterized as a novel homogenous polysaccharide with potent in vitro anticomplement activity (CH50: 0.126 ± 0.002 mg/mL), containing 10.51% uronic acids and 9.67% flavonoids, which were similar to the composition of MBAP90. The backbone of MBAP-3 consisted of →4)-α-D-Glcp-(1→, →3,4,6)-α-D-Glcp-(1→, and →3,4)-α-D-Glcp-(1→, with branches comprising α-L-Araf-(1→, α-D-GlcpA-(1→, →4,6)-α-D-Manp-(1→ and →4)-ß-D-Galp-(1 â†’ . Particularly, O-6 of →4)-ß-D-Galp-(1→ was conjugated with a flavonoid, myricetin. CONCLUSIONS: MBAP90 could ameliorate H1N1-ALI by inhibiting inflammation and over-activation of the complement system. These polysaccharides (MBAP90 and MBAP-3) with relative high contents of uronic acid and flavonoid substituent might be vital components of T. chinensis for treating viral pneumonia.

Physicochemical properties and bioactivity of polysaccharides from Isaria cicadae Miquel with different extraction processes: effects on gut microbiota and immune response in mice.

The effect of different extraction processes on the physicochemical characterization, digestibility, antioxidant activity and prebiotic activity of Isaria cicadae Miquel (ICM) fruiting body polysaccharides was studied. Furthermore, the effect of ultrasound-assisted extraction of ICM (U-ICM) on gut microbiota, the intestinal barrier and immune response was deeply explored. This study found that ICMs showed high indigestibility in both α-amylase and artificial gastric juice, indicating that ICMs have the potential as dietary fiber. In contrast, U-ICM had the best antioxidant activity and prebiotic potential. Meanwhile, there was a structure-activity relationship between the antioxidant activity of ICMs and the content of uronic acid, arabinose and galactose. When healthy mice were fed U-ICM for 42 days, the relative abundances of Lactobacillus, Akkermansia, and Bacteroides were found to increase significantly, while that of Clostridium decreased significantly. Meanwhile, U-ICM significantly promotes the expression of tight junction protein and the production of cytokines, indicating that U-ICM had the function of enhancing the intestinal barrier and regulating the host immune response. In conclusion, U-ICM as dietary fiber has the potential to be developed as a gut health-promoting prebiotic component or functional food. This research provided a valuable resource for further exploring the structure-activity relationship and prebiotic activity of ICMs.

Entropy-driven binding of gut bacterial ß-glucuronidase inhibitors ameliorates irinotecan-induced toxicity.

Irinotecan inhibits cell proliferation and thus is used for the primary treatment of colorectal cancer. Metabolism of irinotecan involves incorporation of ß-glucuronic acid to facilitate excretion. During transit of the glucuronidated product through the gastrointestinal tract, an induced upregulation of gut microbial ß-glucuronidase (GUS) activity may cause severe diarrhea and thus force many patients to stop treatment. We herein report the development of uronic isofagomine (UIFG) derivatives that act as general, potent inhibitors of bacterial GUSs, especially those of Escherichia coli and Clostridium perfringens. The best inhibitor, C6-nonyl UIFG, is 23,300-fold more selective for E. coli GUS than for human GUS (Ki = 0.0045 and 105 µM, respectively). Structural evidence indicated that the loss of coordinated water molecules, with the consequent increase in entropy, contributes to the high affinity and selectivity for bacterial GUSs. The inhibitors also effectively reduced irinotecan-induced diarrhea in mice without damaging intestinal epithelial cells.

Paeoniae radix alba polysaccharides obtained via optimized extraction treat experimental autoimmune hepatitis effectively.

The extraction process of Paeoniae radix alba polysaccharides (PRAP) was optimized as the liquid-solid ratio of 10.65 mL/g, the extraction time of 2.10 h, and the 2 extraction repetitions through a response surface methodology. The chemical profiles of the obtained PRAP were characterized by measuring the contents of total carbohydrates, total phenolics, uronic acid and protein, and by analyzing the FT-IR spectrum and monosaccharide composition. To determine the therapeutic effects of PRAP on experimental autoimmune hepatitis (EAH), we established an EAH mice model. After treated with PRAP, liver and spleen injuries were reduced, and hepatocyte regeneration and liver function were improved. Further study of the mechanism by which PRAP treats EAH showed that PRAP significantly inhibited oxidative stress in the livers of EAH model mice. More importantly, PRAP inhibited immune inflammatory reactions in EAH model mice, including the hepatic infiltration of inflammatory CD4+ and CD8+ T cells, as well as overexpression of inflammatory cytokines IL-2, IL-6 and IL-10, via inhibition of the NF-κB signaling pathway.

Enzymatic preparation of a low-molecular-weight polysaccharide rich in uronic acid from the seaweed Laminaria japonica and evaluation of its hypolipidemic effect in mice.

Here, we describe a method combining thermo-acid pretreatment and alginate lyase hydrolysis to prepare a low-molecular-weight polysaccharide from the seaweed Laminaria japonica (SP). The in vitro results showed that SP displayed obvious absorption of oil (2.95 g g-1) and cholesterol (21.87 g g-1 at pH 2.0). In addition, the in vivo assessment of SP-related anti-obesity effects in C57BL/6J mice fed a high-fat diet and treated with SP for 8 weeks revealed that SP significantly reduced weight gain and lipid accumulation in white adipose and liver tissues, improved serum lipid profiles, and ameliorated intestinal damage. Moreover, SP activated the AMP-activated protein kinase pathway in liver tissues, downregulated sterol regulatory element-binding protein and fatty acid synthase, and suppressed lipid synthesis. These findings indicated that SP extracted from L. japonica might represent a potent functional food exhibiting anti-obesity effects.

Mechanism of Antibacterial Activity of Bacillus amyloliquefaciens C-1 Lipopeptide toward Anaerobic Clostridium difficile.

Probiotics may offer an attractive alternative for standard antibiotic therapy to treat Clostridium difficile infections (CDI). In this study, the antibacterial mechanism in vitro of newly isolated B. amyloliquefaciens C-1 against C. difficile was investigated. The lipopeptides surfactin, iturin, and fengycin produced by C-1 strongly inhibited C. difficile growth and viability. Systematic research of the bacteriostatic mechanism showed that the C-1 lipopeptides damage the integrity of the C. difficile cell wall and cell membrane. In addition, the lipopeptide binds to C. difficile genomic DNA, leading to cell death. Genome resequencing revealed many important antimicrobial compound-encoding clusters, including six nonribosomal peptides (surfactins (srfABCD), iturins (ituABCD), fengycins (fenABCDE), bacillibactin (bmyABC), teichuronic, and bacilysin) and three polyketides (bacillaene (baeEDLMNJRS), difficidin (difABCDEFGHIJ), and macrolactin (mlnABCDEFGHI)). In addition, there were other beneficial genes, such as phospholipase and seven siderophore biosynthesis gene clusters, which may contribute synergistically to the antibacterial activity of B. amyloliquefaciens C-1. We suggest that proper application of antimicrobial peptides may be effective in C. difficile control.

Microwave-Assisted Extraction, Purification, Partial Characterization, and Bioactivity of Polysaccharides from Panax ginseng.

Polysaccharides are a main active substance in Panax ginseng; however, microwave-assisted extraction used to prepare P. ginseng polysaccharides (MPPG) has rarely been reported, and knowledge of the bactericidal activity of P. ginseng polysaccharides remains low. Thus, this study was designed to investigate the extraction of P. ginseng polysaccharides by using two methods-hot water extraction and microwave-assisted extraction-and compare their chemical composition and structure. In addition, their antibacterial and antioxidant activities were also determined. The data implied that P. ginseng polysaccharides extracted by microwave-assisted extraction possessed a higher extraction yield than hot water extraction (WPPG) under optimized conditions, and the actual yields were 41.6% ± 0.09% and 28.5% ± 1.62%, respectively. Moreover, the preliminary characterization of polysaccharides was identified after purification. The WPPG with the molecular weight (Mw) of 2.07 × 105 Da was composed of Man, Rib, Rha, GalA, Glu, Gal, and Arab, and the typical characteristics of polysaccharides were determined by IR spectra. Compared with WPPG, MPPG had a higher Mw, uronic acid content, and Glu content. More importantly, the antioxidant activity of MPPG was higher than WPPG, which was probably ascribed to its highly Mw and abundant uronic acid content. Besides, both of them exhibited high bactericidal activity. These results demonstrate that microwave-assisted extraction is an effective method for obtaining P. ginseng polysaccharides, and MPPG could be applied as an antioxidant and antibacterial agent.

Evaluation of the Effect of α-L-Guluronic Acid (G2013) on COX-1, COX-2 Activity and Gene Expression for Introducing this Drug as a Novel NSAID with Immunomodulatory Property.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat the pathological pain and inflammation through inhibition of cyclooxygenase (COX) enzyme and disruption of the synthesis of prostaglandins (PGs). The α-L-guluronic acid (G2013) patented (PCT/EP2017/067920), as a novel NSAID with the immunomodulatory property, has been shown its positive effects in experimental models of multiple sclerosis and anti-aging. OBJECTIVE: This study was aimed to investigate the effects of G2013 on the gene expression and activity of COX-1/COX-2 enzymes in order to introduce a novel NSAID for the treatment of inflammatory diseases. METHOD: The mRNA expression levels of COX-1/COX-2 were measured by qRT-PCR. The PGE2 concentration in culture media was determined using ELISA method. RESULTS: Our results demonstrated that the low and high dose of G2013 could significantly reduce the gene expression of COX-1 and COX-2, as compared to the control treated with LPS (p < 0.05). In addition, data showed that 5, 50 and 500 mMol/ml doses of this drug can significantly the reduce activities of COX-1 and COX-2, as compared to the control treated with LPS and AA (p < 0.0001). CONCLUSION: This study revealed that G2013, as a novel NSAID with the immunomodulatory property, is able to reduce the gene expression and activity of COX-1/COX-2 enzymes. According to the findings, this agent might be categorized and introduced as a novel NSAID for the treatment of inflammatory diseases.

Enzymatic Extraction, Purification, and Characterization of Polysaccharides from Penthorum chinense Pursh: Natural Antioxidant and Anti-Inflammatory.

Penthorum chinense Pursh (PCP) is a kind of functional food or medicine for liver protection. In the present work, Plackett-Burman design, steepest ascent method, and response surface methodology (RSM) were employed to obtain maximum total sugar yield. The experimental yield of 6.91% indicated a close agreement with the predicted yield of 7.00% of the model under optimized conditions. The major polysaccharide fraction (PCPP-1a) from PCPP was purified and identified as acidic polysaccharides with a high content of uronic acid (FT-IR, UV, HPGPC). PCPP had similar monosaccharide profile with PCPP-1a but was rich in galacturonic acid (HPLC). Both of PCPP and PCPP-1a possessed strong hydroxyl radical scavenging, DPPH radical scavenging, and Fe2+ chelating activities. Moreover, they were revealed to show strong anti-inflammatory activities by inhibiting NO, TNF-α, and IL-1ß release compared to LPS treatment in RAW264.7 cells. These data suggest that the polysaccharides from PCP could be potential natural products for treating ROS and inflammatory-related diseases.

Preclinical and pharmacotoxicology evaluation of α-l-guluronic acid (G2013) as a non-steroidal anti-inflammatory drug with immunomodulatory property.

CONTEXT: Therapeutic effects of α-l-guluronic acid with the greatest tolerability and efficacy (G2013) have been shown in experimental model of multiple sclerosis and other in vitro and in vivo examinations regarding α-l-guluronic acid; there are no toxicological researches on its safety although the pharmacological impacts have been recorded. OBJECTIVE: This study was designed to determine the acute and sub chronic toxicity of α-l-guluronic acid in healthy male and female BALB/c mice. MATERIALS AND METHODS: For the acute toxicity study, the animals orally received five different single doses of α-l-guluronic acid and were kept under observation for 14 d. In the sub-chronic study, 24 male and female BALB/c mice were divided into four groups and treated daily with test substance preparation at dose levels of 0, 50, 250, and 1250 mg/kg body weight for at least 90 consecutive days. The mortality, body weight changes, clinical signs, hematological and biochemical parameters, gross findings, histopathological, and organs weight determinants were monitored during this study. RESULTS: The results of acute toxicity indicated that the LD50 of α-l-guluronic acid is 4.8 g/kg. We found no mortality or abnormality in clinical signs, body weight, relative organs weight, or necropsy in any of the animals in the subchronic study. Additionally, the results showed no significant difference in hematological, biochemical, and histopathological parameters in rats. CONCLUSIONS: Our results suggest that α-l-guluronic acid has high safety when administered orally in animals.

G2013 modulates TLR4 signaling pathway in IRAK-1 and TARF-6 dependent and miR-146a independent manner.

Inflammation is inseparable part of different diseases especially cancer and autoimmunity. During inflammation process toll like receptor 4(TLR4) responds to lipopolysaccharide (LPS), one of the bacterial components, and TLR4 signaling leads to interleukine-1 receptor associated kinase-1 (IRAK1) and tumor necrosis factor (TNF) receptor associated factor6 (TRAF6) activation which ultimately results in nuclear factor- ĸB (NF-ĸB) activation as the main transcription factor of inflammatory cytokines. Conversely, NF-ĸB over activation induces miR-146a in innate immune cells which can consequently reduce TRAF6, IRAK1, and NF-ĸB activation in a negative feedback. G2013 is a novel designed non-steroidal anti-inflammatory drug (NSAID) which was recently shown to be effective in experimental autoimmune encephalomyelitis (EAE) mouse model. The aim of this study was to evaluate G2013 effects on inflammatory (IRAK1 and TRAF6) and anti-inflammatory (miR-146a) factors of TLR4 signaling pathway. For this purpose, cytotoxicity of G2013 has been evaluated by MTT assay. Expression level of miR-146a in PBMCs and IRAK1 along with TRAF6 in HEK-293 TLR4 cells have been determined using real time PCR. Our results showed that IC50 of G2013 was 25µg/ml, thus 5 and 25 µg/ml concentrations used for further treatments as low dose and high dose concentrations. Our results showed that IRAK1 expression reduced between 5 to 8 fold after treatment by G2013 in a dose dependent manner (p<0.001). In parallel TRAF6 expression declined between 3 to 10 fold dose dependently (p<0.05). However, miR-146a expression was not affected after treatment with low dose and high dose of G2013. In conclusion our data showed that G2013 can regulate TLR4 signaling pathway during inflammation by reducing downstream signaling molecules, IRAK1 and TRAF6 without altering miR-146a expression.

Isouronium and N-hydroxyguanidinium derivatives as Cell growth inhibitors: A comparative study.

Based on the results obtained from a computational study on the suitability of the isouronium and N-hydroxyguanidinium cations as hydrogen bond donors/acceptors, the DNA binding of a series of isouronium derivatives was assessed by DNA thermal denaturation experiments and compared to related N-hydroxyguanidines. Due to the poor DNA binding observed, the nature of the diaromatic linker was explored by preparing the corresponding amide-linked bis-isouronium derivative and measuring its DNA affinity. Next, the inhibitory effects of the isouronium derivatives on cell viability were evaluated in two different cancer cell lines providing IC50 values in the range of 36.9-57.4 µM (HL-60, leukemia), and 17.3-33.9 µM (Kelly, neuroblastoma). These values are comparable to those previously found for the N-hydroxyguanidine series. Compounds with the -S- linker (3, 6, and 10) proved to be considerably active in the HL-60 cells and even more active in the Kelly cell line. No correlation was found between DNA minor groove binding and cell growth inhibition; hence, activity may depend on different modes of action. Further studies into the apoptotic potential of these compounds indicated that, besides inhibiting cell viability and proliferation, derivatives 9 and 10, are significant apoptosis-inducers in both cell lines. Results obtained with HL-60 cells suggest that G2/M arrest and subsequent apoptosis induced by compound 10 are associated with microtubular depolymerisation, loss of mitochondrial membrane potential and activation of the caspase cascade. Moreover, the effects of compound 10 on cell viability and apoptosis in two non-cancereous cell lines (NIH3T3 and MCF-10A) indicate none or minimal toxicity.

Purification, structural characterization and anticancer activity of the novel polysaccharides from Rhynchosia minima root.

Three novel acidic polysaccharides termed PRM1, PRM3 and PRM5 were purified from Rhynchosia minima root using DEAE-52 cellulose and sephadex G-150 column chromatography. Their structures were characterized by ultraviolet (UV) and Fourier transform infrared (FTIR) spectrometry, gel permeation chromatography (GPC), gas chromatography-mass spectrometry (GC-MS), and differential scanning colorimeter (DSC) analysis. The uronic acid contents of PRM1, PRM3 and PRM5 were 30.7%, 12.7% and 47.7%, respectively. PRM1 (143.2 kDa), PRM3 (105.3 kDa) and PRM5 (162.1 kDa) were heteropolysaccharides because they were composed of arabinose, mannose, glucose and galactose. Their enthalpy values were 201.0, 111.0 and 206.8 J/g, respectively. PRM3 and PRM1 exhibited strong in vitro anticancer activity against lung cancer A549 and liver cancer HepG2 cells in a dose-dependent manner. These findings suggested that PRM1 and PRM3 could be potentially developed as natural anticancer agents.

New therapeutic approach by G2013 in experimental model of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that leads to an inflammatory demyelination and axonal damage. MS disease often displays a relapsing-remitting course of neurological manifestations that is mimicked by experimental autoimmune encephalomyelitis (EAE) in animal models. The aim of the present research was to test the therapeutic effect of small molecule G2013, a novel designed non-steroidal anti-inflammatory agent in EAE. All experiments were conducted on C57BL/6 male mice aged 10 weeks. To induce the EAE, we performed subcutaneously injection of myelin oligodendrocyte glycoprotein-35-55 (MOG35-55) in Complete Freund's Adjuvant (CFA) emulsion, and for treatment of EAE we used intraperitoneal (IP) injection of G2013. On day 21 post-immunization, for total antioxidant, nitric oxide (NO) and TNF-α assessment, blood samples were taken from the heart and mice were killed, and the brains and cerebellums were then removed for histological analysis. Our findings demonstrated that G2013 had beneficial effects on EAE by lower incidence, attenuation in the severity, and a delay in the onset of disease. Histological analysis showed that inflammation criteria including the number of inflammatory cells and plaques as well as demyelination in G2013 dosed mice were lower than control group. Moreover, the serum level of NO in G2013-treated mice was significantly less than control animals. These data indicate that G2013 therapy can attenuate the disease progression in experimental model of MS.

Structural characterization and stimulating effect on osteoblast differentiation of a purified heteropolysaccharide isolated from Hedysarum polybotrys.

Radix Hedysari polysaccharides (HPS) is the principal active fraction of Radix Hedysari (RH). The information about HPS3d, the main fraction of HPS3, and its effect on bone is still unknown. In the present study, the purified HPS3d was obtained by anion-exchange column. It consisted of 94.38% polysaccharide, 3.40% protein and 13.30% uronic acid. The molecular weight was measured to be 84.6kDa. The backbone consisted of galactopyranose and galacturonopyranose, and the side chains were composed of glucopyranose, rhamnopyranose and arabinofuranose. The FT-IR and elemental analysis showed that HPS3d was the sulfated polysaccharide. HPS3d upregulated alkaline phosphatase (ALP) activity and the expression of other osteogenic marker genes in osteoblast. In addition, HPS3d increased the expression and transcriptional activity of Runt-related transcription factor 2 (Runx-2) and Osterix, the two master genes of osteoblast differentiation. These findings suggest that HPS3d stimulates osteoblast differentiation by activation of Runx-2 and Osterix.

Antiviral activities of sulfated polysaccharides isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales).

Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 µg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC50 of 4.1 and 17.2 µg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively.

Inhibitory effect of a hot water extract of coffee "silverskin" on hyaluronidase.

Coffee "silverskin" (CS) is a by-product of the roasting procedure for coffee beans. A CS extract (CS-ext) was found to have a high inhibitory effect against hyaluronidase. It seems that the higher-molecular-weight substances in CS-ext contributed most to the hyaluronidase inhibition, while acidic polysaccharides mainly composed of uronic acid played a major role in this hyaluronidase inhibition by CS-ext.

Effects of glucosamine derivatives and uronic acids on the production of glycosaminoglycans by human synovial cells and chondrocytes.

Glucosamine (GlcN) has been widely used to treat osteoarthritis (OA) in humans. However, its chondroprotective action on the joint is poorly understood. In this study, to elucidate the chondroprotective action of GlcN, we examined the effects of GlcN-derivatives (GlcN and N-acetyl-D-glucosamine) and uronic acids (D-glucuronic acid and D-galacturonic acid) (0.1-1 mM) on the production of glycosaminoglycans (GAG), such as hyaluronic acid (HA), keratan sulfate and sulfated GAG by human synovial cells and chondrocytes. The results indicate that among GlcN-derivatives and uronic acids, GlcN but not N-acetyl-D-glucosamine, D-glucuronic acid and D-galacturonic acid induce the production of HA by synovial cells and chondrocytes at >0.25 and >0.1 mM (p<0.05), respectively, and the production levels are much higher (>10-fold) in synovial cells compared to chondrocytes. In contrast, neither N-acetyl-D-glucosamine, D-glucuronic acid nor D-galacturonic acid affected the production of keratan sulfate and sulfated GAG by these cells. Moreover, the experiments with 3H-labeled GlcN indicated that GlcN can be incorporated and utilized for the production of GAG (including HA) by synovial cells and chondrocytes. In addition, GlcN (1 mM) up-regulates the expression of HA-synthesizing enzymes (hyaluronan synthases) in synovial cells and chondrocytes. Together these observations indicate that GlcN may exhibit chondroprotective action on joint diseases such as OA by modulating the expression of HA-synthesizing enzymes and inducing the production of HA (a major component of GAG contained in synovial fluid) especially by synovial cells.

A substance P mediated pathway contributes to 6-hydroxydopamine induced cell death.

The neurotoxin 6-hydroxydopamine (6-OHDA) is used to induce dopaminergic cell death, resulting in insufficient striatal dopamine content in the basal ganglia and motor dysfunction typical of Parkinson's disease. Dopamine induces release of the neuropeptide substance P (SP) within the substantia nigra, whereas SP is able to potentiate striatal dopamine release, thus creating a positive feedback mechanism. Previous studies, however, have shown that elevated SP is detrimental to neuronal survival and motor function in acute brain injury. In the current study, we demonstrate that 6-OHDA increases SP production in meso-striatal organotypic co-culture. Moreover, there was a significant correlation between SP content and lactate dehydrogenase release, a marker of cell death, suggesting elevated SP production may contribute to 6-OHDA induced cell death in vitro.

Composition and properties of biologically active pectic polysaccharides from leek (Allium porrum).

BACKGROUND: Leek (Allium porrum) is very commonly used vegetable in Bulgaria and is distinctive with high content of bioactive components. Previously we obtained five crude pectic polysaccharides from leek through consecutive extraction. Some of them appeared to be good stimulators of the immune system. Schols and Voragen investigated the composition of modified hairy regions of pectic polysaccharides isolated from leek cell walls. Samuelson et al. identified the polysaccharide structures encountered in hairy regions as bioactive. The aim of this work was to study the isolation, composition and biological activities of pectic polysaccharides from leek. RESULTS: Two pectic polysaccharides from leek were isolated through consecutive water and acid extraction. The water extractable pectin had higher polyuronic content, higher protein content and lower neutral sugar content. It was found that next to galacturonic acid they also contain glucuronic acid in ratio 9:1 for the water- and 3:1 for the acid-extractable polysaccharide. The main neutral sugar was galactose. The water-extractable pectic polysaccharide had higher molecular weight (10(6) Da) and homogeneity. It was shown that the pectic polysaccharides from leek have considerable immunostimulating activities. CONCLUSION: Leek polysaccharides have relatively high galacturonic and glucuronic acid content and are distinguished with high biological activity.