The Anti-Inflammatory Effect of Carrageenan/Echinochrom Complex at Experimental Endotoxemia.

The anti-inflammatory effects of the CRG/Ech complex in LPS-induced endotoxemia were investigated in vivo in mice and in vitro in LPS-stimulated RAW 264.7 cells and peritoneal macrophages. The results indicated that the CRG/Ech complex suppressed the LPS-induced inflammatory response by reducing the production of ROS and NO in the macrophages. Furthermore, the in vivo experiment indicated that the CRG/Ech complex minimized disorders of the physiological and metabolic processes in mice subjected to LPS intoxication and reduced the levels of proinflammatory cytokines in the mouse serum. The preventive administration of the CRG/Ech complex to mice prevented endotoxin-induced damage in the mouse model of endotoxemia, increased the mice's resistance to LPS, and prevented increases in the levels of proinflammatory cytokines (TNFα). In this work, we showed by the molecular docking that Ech interacted with carrageenan, and that H-donor and H-acceptor bonds are involved in the formation of the complex.

The Comparative Immunotropic Activity of Carrageenan, Chitosan and Their Complexes.

The immunotropic activity of polyelectrolyte complexes (PEC) of κ-carrageenan (κ-CGN) and chitosan (CH) of various compositions was assessed in comparison with the initial polysaccharides in comparable doses. For this, two soluble forms of PEC, with an excess of CH (CH:CGN mass ratios of 10:1) and with an excess of CGN (CH: CGN mass ratios of 1:10) were prepared. The ability of PEC to scavenge NO depended on the content of the κ-CGN in the PEC. The ability of the PEC to induce the synthesis of pro-inflammatory (tumor necrosis factor-α (TNF-α)) and anti-inflammatory (interleukine-10 (IL-10)) cytokines in peripheral blood mononuclear cell was determined by the activity of the initial κ-CGN, regardless of their composition. The anti-inflammatory activity of PEC and the initial compounds was studied using test of histamine-, concanavalin A-, and sheep erythrocyte immunization-induced inflammation in mice. The highest activity of PEC, as well as the initial polysaccharides κ-CGN and CH, was observed in a histamine-induced exudative inflammation, directly related to the activation of phagocytic cells, i.e., macrophages and neutrophils.

Effects of Carrageenans on Biological Properties of Echinochrome.

Sea urchin pigment echinochrome A (Ech), a water-insoluble compound, is the active substance in the cardioprotective and antioxidant drug Histochrome® (PIBOC FEB RAS, Moscow, Russia). It has been established that Ech dissolves in aqueous solutions of carrageenans (CRGs). Herein, we describe the effects of different types of CRGs on some properties of Ech. Our results showed that CRGs significantly decreased the spermotoxicity of Ech, against the sea urchin S. intermedius sperm. Ech, as well as its complex with CRG, did not affect the division and development of early embryos of the sea urchin. Ech reduced reactive oxygen species production (ROS) in neutrophils, caused by CRG. The obtained complexes of these substances with pro- and anti-activating ROS formation properties illustrate the possibility of modulating the ROS induction, using these compounds. The CRGs stimulate the induction of anti-inflammatory IL-10 synthesis, whereas Ech inhibits this synthesis and increases the production of the pro-inflammatory cytokines IL-6 and TNFα. The inclusion of Ech, in the complex with the CRGs, decreases Ech's ability to induce the expression of pro-inflammatory cytokines, especially TNFα, and increases the induction of anti-inflammatory cytokine IL-10. Thus, CRGs modify the action of Ech, by decreasing its pro-inflammatory effect. Whereas, the Ech's protective action towards human epithelial HT-29 cells remains to be unaltered in the complex, with κ/ß-CRG, under stress conditions.

Furostane Series Asterosaponins and Other Unusual Steroid Oligoglycosides from the Tropical Starfish Pentaceraster regulus.

Seven new asterosaponins, pentaregulosides A-G (1-7), including two furostane-type steroid oligoglycosides (2, 3), along with four previously known compounds (8-11) were isolated from the ethanolic extract of the starfish Pentaceraster regulus, collected off the coast of Vietnam. The structures of 1-7 were elucidated by extensive NMR and ESIMS techniques as well as chemical transformations. The aglycons of compounds 1 and 3 have not previously been observed in starfish steroid oligoglycosides, while the aglycons of compounds 2 and 4-6 are very rare for this structural group. Compound 1 exhibited cytotoxic activity with an IC50 value of 6.4 ± 0.3 µM against RAW 264.7 murine macrophages. In contrast, nontoxic asterosaponins 3, 4, and 5 showed a potential immunomodulatory action at a concentration of 5 µM, reducing by 40%, 28%, and 55%, respectively, reactive oxygen species formation in the RAW 264.7 cells, co-stimulated with the pro-inflammatory endotoxic lipopolysaccharide from E. coli.

Partial structure and immunological properties of lipopolysaccharide from marine-derived Pseudomonas stutzeri KMM 226.

The partial structure and immunology of the lipopolysaccharide (LPS) of Pseudomonas stutzeri KMM 226, a bacterium isolated from a seawater sample collected at a depth of 2000 m, was characterised. The O-polysaccharide was built up of disaccharide repeating units constituted by L-Rhap and D-GlcpNAc: →2)-α-L-Rhap-(1→3)-α-D-GlcpNAc-(1→. The structural analysis of the lipid A showed a mixture of different species. The major species were hexa-acylated and penta-acylated lipids A, bearing the 12:0(3-OH) in amide linkage and 10:0(3-OH) in ester linkage, while the secondary fatty acids were present only as 12:0. The presence of 12:0(2-OH) was not detected. The immunology experiments demonstrated that P. stutzeri KMM 226 LPS displayed a low ability to induce TNF-α, IL-1ß, IL-6, IL-8 and IL-10 cytokine production and acted as an antagonist of hexa-acylated Escherichia coli LPS in human blood in vitro.

Stenting of the artery of Dr A.N. Kazantsev in the acute period of ischemic stroke.

The A.N. Kazantsev artery is a vessel starting from the common carotid artery with subsequent bifurcation into 2 vessels of equal size-the internal carotid artery (ICA) and the persistent embryonic hypoglossal artery (PEHA). Until now, this artery has been considered as the ICA. However, according to all existing classifications, the ICA in the cervical segment does not have arterial branches. In addition, in view of the comparable sizes of PEHA and ICA, PEHA itself cannot be considered a branch of the ICA. Thus, by the right of the first description, the authors of the article named this vascular formation as the A.N. Kazantsev artery, which forms a bifurcation of the PEHA and ICA. In this clinical case, carotid angioplasty (CAS) was performed with stenting of 80% stenosis of the A.N. Kazantsev artery in the most acute period of acute cerebrovascular accident (ACV). According to angiography, the following was also revealed: the presence of PEHA, extending from the A.N. Kazantsev artery 5 cm above its mouth, connecting with the main artery; stenosis of the right vertebral artery 60% at the mouth; hypoplastic left vertebral artery with aplasia of the V4 segment; open circle of Willis (VC): absence of both posterior communicating arteries (PCA). Due to the high risk of recurrent CVA due to clamping of the A.N. Kazantsev artery during CEA, a multidisciplinary consultation decided to implement an emergency CAS of the A.N. Kazantsev artery. The distal embolism protection system FilterWire was inserted into the proximal part of the basilar artery through the radial artery on the left. The distal embolism protection system RX Accunet was inserted into the distal parts of the left ICA through the left common femoral artery. According to Seldinger, an Acculink stent 7-10 × 30 mm was inserted into the affected area of the A.N. Kazantsev artery, positioned and opened. The postoperative period was uneventful. ACV did not recur. Conducted dual antiplatelet therapy (acetylsalicylic acid 125 mg in the afternoon + clopidogrel 75 mg in the morning). The patient was discharged from the institution on the 10th day after the operation in a satisfactory condition.

Structural characteristics of carrageenans of red alga Mastocarpus pacificus from sea of Japan.

The sulfated polysaccharide from sterile alga Mastocarpus pacificus was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the extracted polysaccharides were only carrageenans. According to FT-IR- and NMR spectroscopy this polysaccharide was a hybrid kappa/iota-carrageenan with a predominance of kappa-type units. According to MALDI-TOFMS, oligosaccharide fragments obtained by mild acid hydrolysis had a polymerization degree of 1-9, while chains built up of galactose residues were up to 3. Tandem ESI mass spectrometry together with innovative 18O-labelling method showed that the polymer chain of the carrageenan included kappa-carrabiose, kappa-carratetraose, iota-carrabiose, hybrid kappa/iota oligosaccharide units and contained minor insertions of mu-carrageenan (the precursor of kappa-carrageenan). Parallel artificial membrane permeability assay shown that the studied carrageenan inhibited bile salts permeation through an artificial membrane imitating the gastrointestinal barrier by 50 % on average compared to negative control independent of incubation time. However, its action was less pronounced than the hindering ability of cholestyramine.

Structural analysis and cytokine-induced activity of gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis.

Gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis was studied. According to FT-IR and NMR spectroscopy data, the polysaccharide was found to be iota/kappa-carrageenan with iota- and kappa-type units in a 2:1 ratio containing beta-carrageenan units and minor amounts of nu- and mu-carrageenans. The HPLC and ESI MS/MS data of enzymatic hydrolysis products revealed that the main components of the polymer chain are iota-carrabiose, iota-carratetraose and hybrid tetra- and hexasaccharides consisting of kappa- and iota-units. Xylose was a substituent of a hydroxyl group at C-6 of 1,3-linked ß-d-galactose in the total polysaccharides. It was shown that the ability of carrageenans to increase the synthesis of cytokines depended on their molecular weight. The polysaccharide induced the synthesis of the anti-inflammatory cytokine IL-10, whereas oligosaccharides increased the synthesis of both pro- and anti-inflammatory cytokines at high concentrations.

Influence of red algal sulfated polysaccharides on blood coagulation and platelets activation in vitro.

The influence of sulfated polysaccharides (λ-, κ-, and κ/ß-carrageenan and porphyran) - on platelet activation was studied. Carrageenans were much weaker inhibitors of a coagulation process than heparin, while porphyran had not that effect. Results of the aPTT and PT assays suppose that carrageenans affected mostly intrinsic pathway of coagulation, while their effect on the extrinsic pathway is extremely low (λ and κ/ß) or absent (κ, LMW derivative of κ-carrageenan). λ-Carrageenan was the most potent anticoagulant agent in TT, aPTT, PT, and anti-factor Xa activity. This sample was also the strongest inhibitor of collagen-induced platelet aggregation in PRP. Generally, the correlation of anticoagulant and antithrombotic action in PRP is preserved for carrageenans but not for heparin. Carrageenans and porphyran affected platelet adhesion to collagen by influencing glycoprotein VI. Low molecular weight κ-carrageenan had a similar effect on platelet adhesion mediated with both major collagen receptors: integrin α2 ß1 and glycoprotein VI as native polysaccharide had. Carrageenans resulted in activation of platelets under platelet adhesion mediated by integrin αIIb ß3 with less degree than heparin. The least sulfated κ/ß-carrageenan that possessed an inhibiting effect on thrombin- and collagen-induced aggregation of washed platelets and on the PT test but it had no significant effect on TT was the weakest promoter of integrin αIIb ß3 mediated platelet activation. In summary, our study showed that the polysaccharide action was complex, since it depended on its molecular mass, sulfation degree, and monosaccharide contents (3,6-anhydrogalactose).

Structural peculiarities of polysaccharide from sterile form of Far Eastern red alga Ahnfeltiopsis flabelliformis.

KCl-insoluble sulfated polysaccharide from sterile alga Ahnfeltiopsis flabelliformis was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the polysaccharide comprises disaccharide units of carrabiose only. According to FT-IR-, 1D, 2D NMR spectroscopies and mass-spectrometry this polysaccharide is kappa/beta-carrageenan with ratio of kappa- and beta-types units 3:1 and contains minor amounts of iota- and gamma-carrageenans (precursor of beta-carrageenan). In addition, ESIMS/MS data suggested that xylose (minor amount) is present in the polysaccharide as a substituent one of hydroxyl group of galactose. According to aPTT and PT assays the studied carrageenan affected mostly intrinsic pathway of coagulation, while it effect on the extrinsic pathway is absent.

Effects of structural peculiarities of carrageenans on their immunomodulatory and anticoagulant activities.

Biological activity of five carrageenan types - kappa, kappa/beta, kappa/iota, lambda and new type - iks - isolated from the most abundant species belonging to Gigartinaceae and Tichocarpaceae collected from the Pacific coast was investigated. The ability of carrageenans to influence on the cytokine production by human cells is greatly dependent on concentration and structure of polysaccharides. At high concentrations all types of carrageenans increased the level of pro-inflammatory IL-6 and TNF-α, while at low concentration (1-10ng/mL) their activity was insignificant. All types of carrageenans induced the secretion of anti-inflammatory IL-10 in dose-dependent manner. Hybrid kappa/beta-carrageenan showed fairly high activity independent on concentration. At low concentrations (10ng/mL) its activity was more than that of LPS. The structural analysis of polysaccharides suggests that additional sulphate ester residue of lambda-carrageenan increases the concentration of calcium in macrophage cytoplasm and may have an important role in the activation process of the formation of active oxygen forms. Kappa/iota carrageenan possessed for the potential anticoagulant activity, which was extremely strong in low concentration. These results suggest that the immunomodulation and anticoagulant activity of carrageenans depends on the monosaccharide composition of polysaccharides, number, position and distribution of sulphate groups along galactan chain.