Sulfated-polysaccharides are complex macromolecular constituents of the extracellular matrix of marine algae that play an important role in mechanical, osmotic and ionic regulation.1) In Biomedicine the anticoagulant and antithrombotic properties have been most widely exploited and, at least for galactans, appear to be dependent on the sulfatation content and/or position of the sulfate groups.2) A natural sulfated polymer of L-fucose (fucoidan) showed a dose-dependent inhibition of leukocyte migration in the in vivo peritonitis model, 3) and sulfated fucans isolated from brown algae showed potent in vitro and in vivo inhibition of the human complement system. 4,5) It was demonstrated that a sulfatedpolysaccharide fraction extracted from the brown algae Porphyra haitanesis presents an in vivo antioxidant property, causing an increase in the spleen and thymus size, suggestive of an immunostimulant action. 6) Additionally, sulfated galactans of the red marine algae Bryothamnion seaforthii presented antinociceptive activity in mice 7) and of the red micro algae Pophyridium sp. anti-inflammatory action inhibiting eritema formation after topical use in humans.8) However, studies of sulfated galactans role in models of inflammation in vivo are rare in the literature. Here we isolated and investigated the effects of a sulfated galactan from the red marine algae Champia feldmannii, widely encountered along the South East and North East Brazilian sea coast, in experimental models of acute inflammation, coagulation and nociception. MATERIALS AND METHODS AnimalsMale Wistar rats (150-250 g) and Swiss mice (25-35 g) were maintained with a controlled 12/12 h light/dark cycle, at a temperature of 25°C with free access to food and water. The experimental protocols used in this study were approved by the Institutional Animal Care and Use Committee of the State University of Ceará (UECE), Fortaleza-CE, Brazil, in accordance with international guidelines (NIH publication No. 85-23, revised 1985).Algae Champia feldmannii belongs to the order Rhodymeniales, family Lomentariaceae and was collected in the Pacheco beach of Caucaia, Ceará, Brazil. Algae were classified by Wladimir R. L. Farias, Department of Fishery Engeneering of Federal University of Ceará-Brazil.Erythrocytes Human erythrocytes were obtained from healthy donors at the Hematology Center of the Federal University of Ceará-Brazil.Drugs and Reagents Dextran sulphate, L-carrageenan, Evans blue, zymosan, morphine, cethylpiridinium chloride, sodium acetate, calcium chloride, ketamine, sulphuric acid, papain, 1-9-di-metylene blue (DMB), ethylenodiaminotetracetic acid (EDTA), indomethacin, dexamethasone, pentoxifylline, L-N-nitro-arginine methyl ester (L-NAME), meclyzine and formamide, N-acetyl-N,N,N-trimethylammonium bromide, 1,3-diaminopropane, toluidine blue, agarose gel (Sigma Chemical Co., St. Louis, MO, U.S.A. or SigmaAldrich Chemie, Steinheim, Germany); absolute ethanol, sodium chloride, sodium dodecyl sulfate (SDS) and 2-mer- 907, 60.455-970, Fortaleza-Ceará-Brasil. R...

This paper describes the purification and characterization of a new N-acetyl-d-glucosamine-specific lectin from Araucaria angustifolia (AaL) seeds (Araucariaceae) and its anti-inflammatory and antibacterial activities. AaL was purified using a combination of affinity chromatography on a chitin column and ion exchange chromatography on Sephacel-DEAE. The pure protein has 8.0kDa (SDS-PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the presence of divalent cations and was inhibited after incubation with glucose and N-acetyl-d-glucosamine. AaL showed antibacterial activity against Gram-negative and Gram-positive strains, shown by scanning electron microscopy. AaL, intravenously injected into rats, showed anti-inflammatory effect, via carbohydrate site interaction, in the models of paw edema and peritonitis. This lectin can be used as a tool for studying bacterial infections and inflammatory processes.

This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01-1 mg/kg) in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata or C. brasiliensis (1-100 microg/ml) were performed at the contraction plateau induced by phenylephrine or at tissue basal tonus. The mechanism of the lectin relaxant action was investigated by previous addition of L-NAME, indomethacin, or tetraethylammonium. In both models, the lectin domain involvement was evaluated by incubation of lectins with their ligand and non-ligand sugars. The lectins induced paw edema paralleled by protein leakage. The edematogenic activity elicited by C. gladiata and C. brasiliensis involves prostaglandins and nitric oxide (NO), while that of C. maritima occurs without NO interference. C. gladiata and C. brasiliensis elicited aorta relaxation involving NO and prostacyclin, while that of C. gladiata included EDHF. All lectin effects were prevented by their binding sugars. The present study demonstrated important vasodilator effects of different degrees and mechanisms in vivo and in vitro of Canavalia lectins. In vivo, the edematogenic activity was paralleled by plasma exudation, and in vitro, aorta relaxation was strictly dependent on intact endothelium. All effects occurred via interaction with lectin domains and participation of NO and/or prostanoids.

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(2011) Invivo anti-inflammatory effect of a sulfated polysaccharide isolated from the marine brown algae Lobophoravariegata, Pharmaceutical Biology, 49:2, 167-174,

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The sulfated galactan of the red marine alga Gelidium crinale (SG-Gc) was purified by ion exchange chromatography and tested by intravenous (i.v.) route in rodent experimental models of inflammation and nociception. The anti-inflammatory activity of SG-Gc (0.01, 0.1 and 1 mg/kg) was evaluated in the model of rat paw edema induced by different inflammatory stimuli, while SG-Gc (0.1, 1 and 10 mg/kg) antinociceptive effect was assessed in models of nociception/hyperalgesia elicited by chemical (formalin test), thermal (hot plate), and mechanical (von Frey) stimuli in mice. In addition, the toxicity was evaluated after rat treatment with SG-Gc (1 mg/kg; i.v.) during 10 days, followed by analysis of the wet weight of animal's body/organs and hematological/biochemical parameters. Sulfated galactan of G. crinale inhibited the time course of dextran-induced paw edema, at all doses, showing maximal effect at 1 mg/kg (42%) and that induced by carrageenan at 0.01 (18%) and 1 mg/kg (20%), but was ineffective on the edema elicited by zymosan. At the highest dose, SG-Gc also inhibited the paw edema induced by histamine (49%), compound 48/80 (32%), and phospholipase A(2) (44%). Sulfated galactan of G. crinale inhibited both neurogenic and inflammatory phases of the formalin test, at all doses, and at 10 mg/kg, the animals flinch reaction in the von Frey test in the 1st and 3rd h by 19 and 26%, respectively. Additionally, SG-Gc treatment was well tolerated by animals. In conclusion, SG-Gc presents anti-inflammatory effect involving the inhibition of histamine and arachidonic acid metabolites and also antinociceptive activity, especially the inflammatory pain with participation of the opioid system.

Lectins from Diocleinae subtribe belong to the family of legume lectins and are characterized by high identity between their amino acids sequences. It has been shown that punctual differences in amino acid sequences, such as one single amino acid or an alternative conformation, represent changes in biological activities caused by these lectins. Therefore, a more detailed understanding of three-dimensional structures of these proteins is essential for accurate analyzing the relationship between structure and function. In this study lectins purified from the seeds of Dioclea violacea (DVL) and Dioclea rostrata (DRL) were compared with regard to crystal structure and vasorelaxant properties. Differences in structure of lectins were found to be reflected in differences in vasorelaxant effects based on their high specificity and selectivity for cell glycans. Binding activity was related to the position of specific residues in the carbohydrate recognition domain (CRD). DVL complexed structure was solved by X-ray crystallography and was compared to native DVL and DRL. Therefore, DVL was co-crystallized with X-Man, and a molecular modeling with X-Man complexed with DVL was done to compare the complexed and native forms adjusted fit. The relatively narrow and deep CRD in DVL promotes little interaction with carbohydrates; in contrast, the wider and shallower CRD in DRL favors interaction. This seems to explain differences in the level of relaxation induced by DVL (43%) and DRL (96%) in rat aortic rings.