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-1β), 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)-β-D-Galp-(1 → . Particularly, O-6 of →4)-β-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.

Entropy-driven binding of gut bacterial β-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 β-glucuronic acid to facilitate excretion. During transit of the glucuronidated product through the gastrointestinal tract, an induced upregulation of gut microbial β-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.

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.

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.

Root Growth-promoting Activity of Unsaturated Oligomeric Uronates from Alginate on Carrot and Rice Plants

The root elongation activity of unsaturated oligomeric uronates from alginate on carrot and rice plants was investigated. Unsaturated oligomeric uronates were prepared by digesting polymannuronate (PM) and polyguluronate (PG) with an alginate lyase purified from Pseudoalteromonas sp. strain No. 272. The root elongation activity was measured by elongation in length of carrot- and rice-excised root incubated in the B5-medium containing 0.8% agar in the dark. PM and PG showed no activity, but the enzymatic digestion mixtures of PG had promoting activity on roots of both plants at a final concentration of 0.5 mg/ml. The maximum activity was obtained at 0.75 mg/ml. The dependence of activity on degree of polymerization of the uronates was tested and the pentamer was most active, but the mechanism of the action of unsaturated uronates on the cells remains to be solved.

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.

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.

Biochemical composition of the marine conditioning film: implications for bacterial adhesion

The conditioning film formed on glass panels was analysed for total carbohydrates (CFCHO), total proteins (CFP) and total uronic acids (CFURA). The influence of these compounds on the adhesion of three marine bacterial cultures, Pseudomonas sp. CE-2, Pseudomonas sp. CE-10 and Bacillus sp. SS-10 was also evaluated. One-way analysis of variance suggested a significant increase in the attachment of all three cultures to conditioned glass panels. Moreover, CE-2 (r = 0.874) and CE-10 (r = 0.879) showed a significant positive correlation with CFCHO. Conversely, SS-10 (r = -0.69) showed a significant negative correlation with CFCHO. Backward multiple linear regression analysis indicated that CFCHO were the most predictive component of the conditioning film in explaining bacterial adhesion to the conditioned glass panels.

Two L-amino acid oxidase isoenzymes from Russell's viper (Daboia russelli russelli) venom with different mechanisms of inhibition by substrate analogs

Two isoforms, L(1) and L(2), of L-amino acid oxidase have been isolated from Russell's viper venom by Sephadex G-100 gel filtration followed by CM-Sephadex C-50 ion exchange chromatography. The enzymes, with different isoelectric points, are monomers of 60-63 kDa as observed from size exclusion HPLC and SDS/PAGE. Partial N-terminal amino acid sequencing of L(1) and L(2) showed significant homology with other snake venom L-amino acid oxidases. Both the enzymes exhibit marked substrate preference for hydrophobic amino acids, maximum catalytic efficiency being observed with L-Phe. Inhibition of L(1) and L(2) by the substrate analogs N-acetyltryptophan and N-acetyl-L-tryptophan amide has been followed. The initial uncompetitive inhibition of L(1) followed by mixed inhibition at higher concentrations suggested the existence of two different inhibitor-binding sites distinct from the substrate-binding site. In the case of L(2), initial linear competitive inhibition followed by mixed inhibition suggested the existence of two nonoverlapping inhibitor-binding sites, one of which is the substrate-binding site. An inhibition kinetic study with O-aminobenzoic acid, a mimicking substrate with amino, carboxylate and hydrophobic parts, indicated the presence of three and two binding sites in L(1) and L(2), respectively, including one at the substrate-binding site. An inhibitor cross-competition kinetic study indicated mutually excluding binding between N-acetyltryptophan, N-acetyl-L-tryptophan amide and O-aminobenzoic acid in both the isoforms, except at the substrate-binding site of L(1). Binding of substrate analogs with different electrostatic and hydrophobic properties provides useful insights into the environment of the catalytic sites. Furthermore, it predicts the minimum structural requirement for a ligand to enter and anchor at the respective functional sites of LAAO that may facilitate the design of suicidal inhibitors.

A New Nucleoside Derivative, AJP117510, as an Inhibitor of Integrin α2β1-Collagen Binding

A new nucleoside derivative, AJP117510 (1) was isolated from unidentified fungus AJ117510. The structure of 1 was elucidated by spectroscopic analyses. Nucleoside 1 inhibited the binding of integrin alpha2beta1 to collagen in a dose dependent manner with an IC50 value of 5.9 microM.

Structure−Activity Relationships of 2-Chloro-N6-substituted-4‘-thioadenosine-5‘-uronamides as Highly Potent and Selective Agonists at the Human A3 Adenosine Receptor

We have established structure-activity relationships of novel 4'-thionucleoside analogues as the A(3) adenosine receptor (AR) agonists. Binding affinity, selectivity toward other AR subtypes, and efficacy in inhibition of adenylate cyclase were studied. From this study, 2-chloro-N(6)-methyl-4'-thioadenosine-5'-methyluronamide (36a) emerged as the most potent and selective agonist at the human A(3) AR. We have also revealed that, similar to 4'-oxoadenosine analogues, at least one hydrogen on the 5'-uronamide moiety was necessary for high-affinity binding at the human A(3) AR, presumably to allow this group to donate a H bond within the binding site. Furthermore, bulky substituents on the 5'-uronamide reduced binding affinity, but in some cases large 5'-uronamide substituents, such as substituted benzyl and 2-phenylethyl groups, maintained moderate affinity with reduced efficacy, leading to A(3) AR partial agonists or antagonists. In several cases for which the corresponding 4'-oxonucleosides have been studied, the 4'-thionucleosides showed higher binding affinity to the A(3) AR.

Angiogenesis and cardioprotection after TNFα-inducer-Tolpa Peat Preparation treatment in rat's hearts after experimental myocardial infarction in vivo

The aim of the presented work was to evaluate whether short subcutaneous (s.c.) administration of TNFalpha-inducer-Tolpa Peat Preparation (TPP or TPP batch 0210) modulates the process of ischemic remodeling and spontaneous angiogenesis after experimental myocardial infarction (MI) in rats in vivo. The results obtained using three complementary and correlative methods: histological studies, Proliferating Cell Nuclear Antigen (PCNA) reaction and Lymphocytes Induced Angiogenesis (LIA) test showed a clear pro-angiogenic and cardioprotective effect of TPP administration after experimental MI. TPP batch 0210 should be considered as an angiogenesis stimulating factor and consecutively as a cardioprotective preventing development of ischemic cardiomyopathy after MI in rats. It might possibly be used as an adjunct to conventional therapy of coronary artery disease, including late phase after myocardial infarction or ischemic cardiomyopathy.

An efficient approach to N-acetyl-d-glucosaminuronic acid-based sialylmimetics as potential sialidase inhibitors

A novel approach to the synthesis of beta-glycosides of N-acetyl-D-glucosaminuronic acid, in six steps and good overall yield from N-acetyl-d-glucosamine, has been developed. The key synthetic step was the Lewis acid mediated O-glycosidation of methyl 1,3,4-tri-O-pivaloyl-N-acetyl-D-glucosaminuronate (11). Elaboration of glucosaminuronides 15 and 18 provided novel sialylmimetics 21 and 22, which showed inhibition of Vibrio cholerae sialidase.

QSAR study of N6-(substituted-phenylcarbamoyl) adenosine-5?-uronamides as agonist for A1 adenosine receptors

The TOPological Sub-Structural Molecular Design (TOPS-MODE) approach has been applied to the study of the affinity of A(1) adenosine receptor of different N(6)-(substituted-phenylcarbamoyl) adenosine-5'-uronamides analogues. A model able to describe close to 84% of the variance in the values for binding experiments of 23 analogues of these compounds through multilinear regression analysis (MRA) was developed with the use of the mentioned approach. In contrast, no one of three different approaches, with the same number of variables, including the use of BCUT, randic molecular profiles, and geometrical descriptors was able to explain more than 75% of the variance in the mentioned property with the same number of descriptors. In addition, the TOPS-MODE approach permitted us to find the contribution of different fragments to the biological property giving the model a straightforward structural interpretability.

Saturation transfer difference (STD) 1H-NMR experiments and in silico docking experiments to probe the binding of N-acetylneuraminic acid and derivatives to Vibrio cholerae sialidase

Saturation transfer difference (STD) (1)H NMR experiments were used to probe the epitope binding characteristics of the sialidase [EC 3.2.1.18] from the bacterium Vibrio cholerae, the causative agent of cholera. Binding preferences were investigated for N-acetylneuraminic acid (Neu5Ac, 1), the product of the sialidase catalytic reaction, for the known sialidase inhibitor 5-acetamido-2,6-anhydro-3,5-dideoxy-D-glycero-D-galacto-non-2-enoic acid (Neu5Ac2en, 2), and for the uronic acid-based Neu5Ac2en mimetic iso-propyl 2-acetamido-2,4-dideoxy-alpha-L-threo-hex-4-enopyranosiduronic acid (3), in which the native glycerol side-chain of Neu5Ac2en is replaced with an O-iso-propyl ether. The STD experiments provided evidence, supporting previous studies, that Neu5Ac (1) binds to the sialidase as the alpha-anomer. Docking experiments using DOCK (version 4.0.1) revealed further information regarding the binding characteristics of the enzyme active site in complex with Neu5Ac2en (2) and the Neu5Ac2en mimetic (3), indicating an expected dominant interaction of the acetamide moiety with the protein.

Enzymatically depolymerized alginate oligomers that cause cytotoxic cytokine production in human mononuclear cells

Enzymatically depolymerized guluronate and mannuronate oligomers were prepared from polyuronates with an alginate lyase from a Pseudoalteromonas sp., and their effects on mononuclear cells from human peripheral blood were examined. Conditioned medium prepared by the incubation of cells with an untreated polyuronate had little effect on growth of human leukemic U937 cells, but a medium prepared with depolymerized uronate oligomers inhibited their growth. Inhibition was greater in a medium prepared with guluronate oligomer than one prepared with mannuronate oligomer. The cytotoxic activity of the medium was heat-labile and nondialyzable. Apoptotic nuclear morphological changes and increased caspase-3-like activity were found in U937 cells treated with a medium prepared with depolymerized uronates. The medium prepared with purified tetra-guluronate and tetra-mannuronate also was cytotoxic; these effects were inhibited by antibodies to tumor necrosis factor-alpha. Our results suggested that enzymatically depolymerized guluronate and mannuronate oligomers induced the production of cytotoxic cytokines in human mononuclear cells, although the uronate polymers before depolymerization had no such activity.

Some biochemical characteristics and water exchange in human articular cartilage in osteoarthrosis

Rearrangement of intra- and intermolecular bonds in collagen molecule, disaggregation of proteoglycans and their elimination from cartilage involved in osteoarthrosis are responsible for water accumulation and its increased mobility in cartilage.

Effect of Traumacel P on the growth of human dermal fibroblasts in vitro

OBJECTIVE

It has been postulated that Traumacel P, a haemostatic powder, might assist the wound-healing process. This in vitro study investigated the effect of the powder on human dermal fibroblasts.

METHOD

Experiments using fibroblasts from a 50-year-old donor were carried out using suspensions of Traumacel P ranging from 0.1 to 10.0 mg/ml. Dulbecco's Modified Eagle Medium with 10% or 0.4% foetal calf serum (FCS) and 5.5 mM or 25 mM glucose was used. The powder was either placed in contact with the cells or separated from them by a porous membrane. The response of the fibroblasts was assessed using the MTT assay.

RESULTS

Concentrations of 0.5 mg/ml and 1.0 mg/ml stimulated the metabolic activity of the fibroblasts in both high and low glucose medium with 10% FCS, regardless of whether the powder was in contact with or separated from the cells. The greatest stimulation, to 174% of the controls, was produced by 0.5 mg/ml Traumacel P in low glucose/10% FCS with the powder in contact with the cells (p < 0.0001). Traumacel concentrations ranging from 0.5 to 5.0 mg/ml in 0.4% FCS significantly stimulated the metabolic activity of fibroblasts in low glucose medium, but not in the high glucose medium.

CONCLUSION

These studies indicate that direct stimulation of fibroblast proliferation may be one of the ways in which Traumacel P aids the healing of ulcers observed in the clinic.

The effect of a peat-based preparation on mitogen-induced proliferation of thymocytes in non-treated and hydrocortisone-suppressed mice

The studies were carried out on Balb/c mice (5-6 weeks of age) treated with a peat-based preparation (PBP), administered i.p. once or four times at 24 h intervals at doses of 0.01; 0.1 or 1 mg/kg. Additionally, hydrocortisone was injected i.p. to selected mice at a single dose of 125 mg/kg. The results show that PBP temporarily enhances the proliferative capability of murine thymocytes stimulated in vitro with concanavalin A (Con A) and phytohemagglutinin (PHA). The effect of PBP depends on the number of subsequent doses, but does not depend on the dose applied. A single PBP administration does not affect the proliferative response of thymocytes to Con A and PHA. A single injection of PBP (doses from 0.01 to 1 mg/kg) does not change the number of thymic cells and weight ratio of this organ. Increased doses of subsequent PBP injections (0.01 and 0.1 mg/kg) do not affect the number of thymocytes, but temporarily increase the weight ratio of the thymus two days after the last injection. Administration of PBP prior to hydrocortisone prevents the suppressive effect of the drug on proliferative response of thymocytes stimulated in vitro with Con A and PHA, at the same time increasing the proliferative response of thymic cells to the two mitogens in relation to the control group (hydrocortisone-free). The effect of a single dose of PBP depends on the dose applied--the weakest preventive effect was observed at a dose of 0.01 mg/kg. An increase in the number of subsequent PBP doses, irrespective of a dose applied, prolongs the protective action of the drug on proliferative activity of thymocytes stimulated in vitro with these mitogenes. Moreover, the results obtained in the studies show that PBP partially prevents the suppressive effect of hydrocortisone, as the number of thymic cells and weight ratio of this organ drastically decreased. PBP accelerates regeneration of the thymus, but this depends on a dose applied and the number of subsequent doses. The result was the strongest and the fastest when PBP was injected four times at a dose of 1 mg/kg. It seems quite likely that the thymic regeneration due to PBP is connected with the effect of this drug on maturation and differentiation of thymic cells.

Micrococcus luteus teichuronic acids activate human and murine monocytic cells in a CD14- and toll-like receptor 4-dependent manner

Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerly Micrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4-12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-alpha) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-alpha-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IV(A), an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.

Lepidimoic acid increases fructose 2,6-bisphosphate in Amaranthus seedlings

This study examines the influence of the growth promoter, lepidimoic acid, on the level of an important cytosolic signal metabolite, fructose 2,6-bisphosphate (Fru-2,6-P2), which can activate pyrophosphatedependent:phosphofructokinase (PFP, EC 2.7.1.90), and on glycolytic metabolism in Amaranthus caudatus seedlings. Fru-2,6-P2 concentrations were respectively increased by approximately 2-, 3- and 4-fold when the seedlings were treated with 0.3, 3 and 30 mM lepidimoic acid. Exogenous lepidimoic acid also affected levels of glycolytic intermediates in the seedlings. The increase in fructose 1,6-bisphosphate and decreases in fructose 6-phosphate and glucose 6-phosphate were found in response to the elevated concentration of lepidimoic acid. These results suggest that lepidimoic acid may affect glycolytic metabolism in the Amaranthus seedlings by increasing the activity of PFP due to increasing level of Fru-2,6-P2.

The research on antioxidative properties of TOŁPA Peat Preparation and its fractions

The protective and therapeutic role of TPP and its fractions against lipid peroxidation in the mitochondria from human placenta as a model for experiments was evaluated. Both TPP and its fractions cause the decrease in MDA production. The antioxidant force of TPP and its fractions with antioxidant force of vitamin E was compared.

Protein kinases induced by osmotic stresses and elicitor molecules in tobacco cell suspensions: two crossroad MAP kinases and one osmoregulation-specific protein kinase

Two protein kinases displaying mitogen-activated protein kinase (MAPK) properties are activated both by an hypoosmotic stress and by oligogalacturonides in tobacco cell suspensions [Cazalé et al. (1999) Plant J. 19, 297-307]. Using specific antibodies, they were identified as the salicylic acid-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK). The SIPK was also activated by an hyperosmotic stress, indicating that the same kinase may play a role both in hypo- and hyperosmotic signalling pathways, in addition to its involvement in the transduction of elicitor signals. Using immunoprecipitation followed by two-dimensional in-gel kinase assay, three molecular forms of the SIPK were observed, suggesting that additional modifications of the activated kinase may occur. In contrast to WIPK and SIPK, which are located at the crossroad of several transduction pathways initiated by elicitor or osmotic stimuli, a 44 kDa kinase, that would not belong to the MAPK family, appeared more specific to osmotic stress.

Development and disappearance of tolerance to induction of interferon and tumor necrosis factor response in athletes treated with natural immunostimulant

The effect of nonspecific immunostimulation was examined in 15 basketball players subjected to extensive physical effort. The Tołpa* Torf Preparation (TTP*), a natural immunostimulating drug, was applied orally, one 5 mg tablet daily, in two 21-day cycles, separated by 2-week hiatus. Blood samples were collected 4 times, after each of two TTP* cycles and after the first and second hiatus. Whole blood assay was used to determine the spontaneous and induced production of interferon (IFN) and tumor necrosis factor (TNF). The levels of the cytokines were measured by microbioassays. TTP* stimulated synthesis of IFN and TNF in the whole blood cultures. However, after the oral administraton of TTP* for 3 weeks the leukocytes of the athletes developed hyporeactivity to IFN induction by TTP* and to a lesser extent to another "superinducer"--a mixture of phytohemagglutinin and bacterial lipopolysaccharide. The hyporeactivity state disappeared spontaneously within 2 weeks. In contrast, the tolerance to TNF induction did not develop during the TTP* administration. The increase of immunoglobulins, mainly of IgM and IgG classes and an acute phase protein--alpha1-antitrypsin, was observed at the late phase of the treatment. We suggest that the cytokine levels may be early markers for immunoprophylaxis. Furthermore, high production of IFN and TNF may be associated with extensive physical effort.

Action of poly (alpha-L-guluronate)lyase from Corynebacterium sp. ALY-1 strain on saturated oligoguluronates

A kinetic analysis of degradation of saturated oligoguluronates by poly(alpha-L-guluronate)lyase from Corynebacterium sp. ALY-1 strain was done. The saturated oligoguluronates were prepared by hydrolyzing poly alpha-1,4-L-guluronate from alginate with HCl, and then by gel filtration on a Bio-Gel P-6 column. The saturated pentaguluronate or above were rapidly degraded by the enzyme, while tetraguluronate was slowly degraded. From the dependency of the catalytic rate constant (kcat) on the degree of polymerization of substrates, the enzyme was found to have a subsite size corresponding to hexaguluronate units. The action pattern of the enzyme on hexaguluronate suggested that the catalytic site of the enzyme was matched to the linkage between the second and third uronic residue from the non-reducing end, since the substrate was mainly split into a unsaturated tetramer and a saturated dimer from a HPLC analysis.

The tumor necrosis factor-inducing potency of lipopolysaccharide and uronic acid polymers is increased when they are covalently linked to particles

Lipopolysaccharide (LPS) and polymers of the uronic acid family stimulate monocytes to produce tumor necrosis factor (TNF). The TNF-inducing potency of these polysaccharides may depend on their supramolecular configuration. In this study detoxified LPS and uronic acid polymers have been covalently linked to particles which have been added to monocytes under serum-free conditions. Reducing the size of mannuronan from 350,000 to 5,500 Da (M-blocks) led to a 10- to 100-fold reduction in TNF-inducing potency. However, covalently linking the M-blocks to monodisperse suspensions of magnetic particles increased the TNF-inducing potency by up to 60,000-fold. Also, the TNF-inducing potency of glucuronic acid polymers was increased when they were linked to particles, but no potentiation was observed with guluronic acid blocks covalently attached to particles. Furthermore, O chains of LPS (detoxified LPS) became potent TNF inducers when they were presented to monocytes on a particle surface. No activation of the LPS-responsive SW480 adenocarcinoma cells was found with detoxified LPS or M-block particles, suggesting a preference for cells expressing CD14 and/or other membrane molecules. The potentiating effects were not restricted to polymers attached to aminated magnetic particles. Of particular interest, we found that short blocks of mannuronan induced TNF production also when covalently linked to biodegradable, bovine serum albumin particles.

Inhibitory effect of alginic acids on hyaluronidase and on histamine release from mast cells

The effects of various types of alginic acid consisting of L-guluronic acids (G) and D-mannuronic acids (M) on hyaluronidase and mast cell degranulation were examined. Alginic acid with an M/G ratio of 1.0 exhibited the strongest inhibition of both activities, the higher molecular weight alginic acids of 150 to 370 kDa being preferable in both cases. Esterification of the carboxyl residue enhanced the latter activity.

TNF production from peripheral blood mononuclear cells in diabetic patients after stimulation with alginate and lipopolysaccharide

Microencapsulated pancreatic Langerhans islets in calcium alginate gels have been used as an implantable bio-artificial pancreas in the treatment of diabetes mellitus, but with limited success due to overgrowth of the capsule with fibroblasts and phagocytes. The authors earlier demonstrated that alginates enriched in mannuronic acid stimulate human monocytes to produce high levels of cytokines such as tumour necrosis factor (TNF), IL-1 IL-6. In this study the authors have measured the TNF production from peripheral blood mononuclear cells (PBMC) in different groups of insulin-dependent diabetes mellitus (IDDM) patients after stimulation with different alginates and lipopolysaccharide (LPS). It was found that high G-alginate did not induce TNF production in any of the groups. High-M alginate and LPS induced a dose-dependent TNF production in all groups and the production was significantly different from unstimulated cells. The highest TNF response was found in newly diagnosed IDDM patients and the lowest was in the controls.

Reduced inhibitory activity of uronic-acid-rich protein in urine of stone formers

We recently reported that human urine contains a newly identified urinary glycoprotein acting as a potent inhibitor against calcium oxalate crystallization. This inhibitor is a uronic-acid-rich protein (UAP) with a molecular weight of approximately 35 kDa. In the present study, UAP was isolated from urine of stone formers and of subjects without a stone history, and its inhibitory activity was tested in a calcium oxalate crystallization system in vitro. Our results show a weaker inhibitory activity of UAP extracted from the urine of stone formers than that extracted from the urine of healthy subjects. Preliminary analyses of amino acid and carbohydrate content showed some differences between the two groups. The main difference was the reduction in sialic acid in UAP isolated from the urine of stone formers. We suggest that UAP contributes significantly to total urinary inhibitory activity of calcium oxalate crystallization and that the decrease in this activity in the urine of recurrent stone formers is due, in part, to the weak inhibitory activity of UAP. A structural abnormality of UAP could explain the diminution of its inhibitory activity in the urine of stone formers.

Cytosolic protons as secondary messengers in elicitor-induced defence responses

A variety of early elicitor-induced membrane responses have been described, and their possible role in the generation of second messengers involved in the cascades of events leading to the activation of defence genes is actively investigated. Treatment of tobacco cells with a crude elicitor preparation from Phytophthora megasperma, purified oligouronides and a commercial pectate lyase, induce a common set of membrane reactions similar to those described in a variety of plant material, i.e. efflux of K+, extracellular alkalinization, net Ca2+ uptake and membrane depolarization. In the same conditions the three elicitors stimulate the activity of phenylalanine ammonia-lyase (PAL) and O-diphenol methyltransferase (OMT), two enzymes of the phenylpropanoid pathway. A good correlation between the intensity of the membrane response and the extent of enzyme stimulation has been observed. Cytosolic acidifications have also been measured as a rapid response to the different elicitor preparations used. These results show that plant cells (which usually succeed in counteracting pH-perturbing processes associated with their metabolism, with the transport of solutes or with the effect of various factors from the environment) display significant variation in the concentration of cytosolic protons in specific physiological circumstances, such as the perception of signals inducing defence reactions. Direct evidence that these cytosolic pH changes could be interpreted by plant cells as messages involved in triggering defence responses is provided by experiments showing that artificial acidifications of the cytoplasm lead to a co-ordinated stimulation of PAL and OMT. These results stress the need to explore in more detail the role played by cytoplasmic mechanisms underlying those pH changes.

Synthesis and biological activity of uronic acid analogues of 2-5A[5'-O-triphosphoryladenylyl(2----5')adenylyl-(2'----5')adenosine]

The oligonucleotide ppp5'A2'p5'A2'p5'A, known as 2-5A, is a potent translational inhibitor involved in some aspects of interferon action. To explore the specific function of the charged 5'-triphosphate moiety, we prepared a series of congeners in which the 5' region was hypermodified. Thus, uronic acid derivatives were substituted for the 5' terminal adenosine residue of 2-5A. Compounds 9, 10, 11 and 12 carried adenosine 5'-uronic acid, ethyl adenosine 5'-uronate, adenosine 5'-uronamide, and adenosine 5'-(N-ethyl)uronamide, respectively, in place of the 5' terminal adenosine triphosphate moiety of 2-5A. While all the analogues showed some weak interaction with the 2-5A-dependent endonuclease (RNase L), compound 9 showed the strongest binding ability, and while unable to activate the mouse RNase L, could activate human RNase at a concentration 100-fold greater than that required for the parent 2-5A. This result suggests that the function of the 5'(poly)phosphate moiety of 2-5A may be fulfilled by some other anionic moiety.

Investigations on some pharmacological properties of TPP

The experiments were performed on mice, rats and rabbits. The influence on circulatory, central nervous, and gastrointestinal system in vivo and in vitro, as well as on renal secretory activity was examined. TPP was administered p.o., i.v. and s.c. at the doses 100.0-400.0 mg/kg. Either in a single dose or multiple doses TPP did not evoke any significant effects (as compared with NaCl solution) on blood pressure, heart and respiratory rate, general behaviour, locomotor activity, body temperature, locomotor coordination, ECoG, smooth muscles of intestine in vivo and in vitro, gastric secretion and on the volume and quality of excreted urine. The augmentation of sodium and potassium ion excretion with urine and slight influence on locomotor coordination both after TPP and 6% NaCl seems to be connected with a high content of salt in TPP.

Escherichia coli serotype-39 capsular polysaccharide: primary structure and depolymerisation by a bacteriophage-associated glycanase

The acidic capsular polysaccharide isolated from Escherichia coli O9:K39:H9 was investigated, using n.m.r. spectroscopy, methylation analysis, uronic acid degradation of the native and methylated polysaccharides, and bacteriophage-associated enzyme degradation. The structure of the repeating unit, which is shown below, is identical to that reported for Klebsiella serotype-61 capsular polysaccharide. (formula; see text)

Suppression of hepatic lipogenesis by pectin and galacturonic acid orally-fed at the separate timing from digestion-absorption of nutrients in rat

This study was conducted to know the possibility that pectin-induced alterations in lipid metabolism of animals might be partly ascribed to galacturonic acid produced by the degradation of ingested pectin in the digestive tract. After a 4-week meal feeding twice a day, fasted rats were fed glucose and fructose and 3 h later orally administered 213 mg of pectin (from apple) or galacturonic acid per kg of body weight, or fed water alone. Significant changes in serum and liver lipids were observed 30 min and 1 h after the administration of pectin and galacturonic acid but not 5 h after the administration. Pectin and galacturonic acid showed contradictory effects on serum lipids, adipose tissue lipoprotein lipase activity and triacylglycerol (TG) production and removal rates. However, the elevation of total lipid and TG levels in liver with the sugar feeding was significantly inhibited by the administration of either pectin or galacturonic acid. These results support our hypothesis that galacturonic acid produced by the degradation of ingested pectin in the digestive tract may be partly responsible for the pectin-induced changes in lipid metabolism. This was discussed in relation to another possible regulation of lipid metabolism by short-chain fatty acids which are produced by the intestinal fermentation of pectin and galacturonic acid.

Aldohexuronate transport system in Erwinia carotovora

The biochemical and physiological aspects of hexuronate transport in Erwinia carotovora were studied to approach the genetic regulation of the hexuronate degradative pathway in this bacterial species. An active transport system for glucuronate and galacturonate uptake exists in E. carotovora. The glucuronate entry reaction displayed saturation kinetics with an apparent Km of 0.05 mM (at 25 degrees C; pH 7). Galacturonate appeared to be a competitive inhibitor of glucuronate uptake with a Ki of 0.1 mM. Glucuronate permeation was not induced by glucuronate itself in wild-type strains. Galacturonate induced the uptake of glucuronate (about fivefold). The induced synthesis of the transport system was sensitive to catabolite repression by glucose. Mutants able to grow on glucuronate as the sole carbon source showed constitutive synthesis of the hexuronate transport system.

"Self-catabolite repression" of pectate lyase in Erwinia carotovora

The induction of pectate lyase of Erwinia carotovora was repressed by a high concentration of its inducer. The concomitant addition of cyclic adenosine 3',5'-monophosphate reversed this repression.

Synthesis and biological activities of some uronic acids, uronates, uronamides, and urononitriles of pyrimidine nucleosides

The 5'-hydroxymethylene function of several uracil and cytosine nucleosides has been modified to produce a variety of uronic acids, uronates, uronamides, and urononitriles of 2'-deoxy-beta-D-erythro-pentofuranosyl- and beta-D-arabino-pentofuranosylpyrimidines. In addition, the 5 position in many of these nucleosides has been substituted by a halogen atom. Twenty-one of the 35 compounds synthesized and examined for biological activity have not been previously reported. The purity of the products was measured by a high-pressure liquid chromatographic method. They were then evaluated as potential growth inhibitors of murine Sarcoma 180 cells in culture, of herpes simplex virus type 1 in vitro, and of Streptococcus faecium, a folic acid or deoxythymidine dependent bacterial strain. The ability of these nucleoside analogues to inhibit the phosphorylation of deoxythymidine by herpes simplex virus type 1 encoded pyrimidine deoxyribonucleoside kinase was also investigated and a structure-activity relationship examined.

Effect of a sulfated polygalacturonic acid on the proliferation of cells in culture

The effect of a low molecular weight sulfated polygalacturonic acid on the growth of BALB/c 3T3 cells and HeLa cells was examined. This chemical reduced the saturation density of 3T3 cells in the range of concentrations of 10(-4) to 1 mg/ml, and inhibited the proliferation of HeLa cells, causing little or no cell damage. Treated cells began to grow after removal of the sulfated polygalacturonic acid. Treatment with this acid also induced enlargement of the cell size in 3T3 cells, and a marked reduction of colony size and of central piling up in HeLa cells. 35S-sulfated polygalacturonic acid was bound to the cells immediately. Electrophoretic mobility of both cell lines treated with this sulfated polygalacturonic acid increased the negative charge of the cell surface. These evidences suggest that sulfated polygalacturonic acid affects the cell surface, restricting the cell growth of both cell lines.

Sequential production of polygalacturonase, cellulase, and pectin lyase by Rhizoctonia solani

The sequence of appearance of cell wall degrading enzymes of Rhizoctonia solani propagules was followed. Polygalacturonase (PG; EC 3.2.1.15) was induced earlier by sodium polypectate (NaPP) as compared with the induction of cellulase (Cx; EC 3.2.1.4) by carboxymethyl cellulose (CMC), cellobiose, or fibrous cellulose powder. Increasing CMC concentration to 0.5% shortened the time of Cx appearance. In Czapek medium containing citrus pectin, pectin lyase (PL; EC 4.2.2.10) was produced faster and at higher amounts than in a medium containing NaPP as the sole carbon source. PG appearance also preceded that of PL in media simultaneously supplemented with their respective inducers. NaPP, which induced production of PG, repressed Cx production. Among the Cx inducers, only CMC and cellobiose repressed PG production to any extent. At pH 6.0, either in a synthetic medium or on autoclaved bean hypocotyl segments, a delay in PG production as compared with Cx and Pl production was observed. Optimal pH levels for enzyme production and activity were 4.0 and 5.0 for PG, and 5.5 for Cx, and 8.0 and 7.5 for PL. PG was less repressed than Cx by glucose, cellobiose, and monogalacturonic acid, while PL was not affected.

Inducibility of beta-glucuronidase in wild-type and hexuronate-negative mutants of Escherichia coli K-12

In strain K-12 of Escherichia coli, beta-glucuronidase synthesis was induced only by beta-glucuronides: all intermediates of the hexuronate pathway able to enter the cells failed to induce the enzyme significantly. The induction pattern of beta-glucuronidase clearly differentiates the mode of regulation of its synthesis from those of the subsequent enzymes of the pathway, which are induced by fructuronate and/or tagaturonate. In mutant strains blocked in glucuronate metabolism after the isomerase step, beta-glucuronidase synthesis was still induced by a beta-glucuronide. Glucuronate and fructuronate, which are accumulated and mutually interconverted within the cells, become good inducers of beta-glucuronidase: they induce up to a level one-half that obtained in the wild-type strain in the presence of beta-glucuronide alone. In an isomerase-negative strain where fructuronate is not produced, beta-glucuronidase was no longer induced by beta-glucuronide unless supplemented with fructuronate. In this strain, glucuronate alone or fructuronate alone exhibited greater inducing ability than in the wild-type strain. Moreover, fructuronate could also enhance glucuronate-induced synthesis of beta-glucuronidase. Glucuronate was not able to activate beta-glucuronideinduced synthesis of beta-glucuronidase. Therefore, the induction of beta-glucuronidase synthesis depends upon two factors which, when acting separately, are both poor inducers but can act cooperatively; one factor is beta-glucuronide or glucuronate and the second is fructuronate. The specific inducing capacity of each of these three compounds as well as the hypothetical mechanism(s) of the action of fructuronate are discussed.