Polysaccharide-rich extract of Genipa americana leaves protects seizures and oxidative stress in the mice model of pentylenetetrazole-induced epilepsy.

Plant polysaccharides have biological activities in the brain and those obtained from Genipa americana leaves present antioxidant and anticonvulsant effects in the mice model of pentylenetetrazole (PTZ)-induced acute seizures. This study aimed to evaluate the polysaccharide-rich extract of Genipa americana leaves (PRE-Ga) in the models of acute seizures and chronic epilepsy (kindling) induced by PTZ. In the acute seizure model, male Swiss mice (25-35 g) received PRE-Ga (1 or 9 mg/kg; intraperitoneal- IP), alone or associated with diazepam (0.01 mg/kg), 30 min before induction of seizures with PTZ (70 mg/kg; IP). In the chronic epilepsy model, seizures were induced by PTZ (40 mg/kg) 30 min after treatment and in alternated days up to 30 days and evaluated by video. Brain areas (prefrontal cortex, hippocampus, striatum) were assessed for inflammatory and oxidative stress markers. Diazepam associated to PRE-Ga (9 mg/kg; i.p.) increased the latency of seizures in acute (222.4 ± 47.57 vs. saline: 62.00 ± 4.709 s) and chronic models (6.267 ± 0.502 vs. saline: 4.067 ± 0.407 s). In hippocampus, PRE-Ga (9 mg/kg) inhibited TNF-α (105.9 ± 5.38 vs. PTZ: 133.5 ± 7.62 pmol/g) and malondialdehyde (MDA) (473.6 ± 60.51) in the chronic model. PTZ increased glial fibrillar acid proteins (GFAP) and Iba-1 in hippocampus, which was reversed by PRE-Ga (GFAP: 1.9 ± 0.23 vs PTZ: 3.1 ± 1.3 and Iba-1: 2.2 ± 0.8 vs PTZ: 3.2 ± 1.4). PRE-Ga presents neuroprotector effect in the mice model of epilepsy induced by pentylenetetrazole reducing seizures, gliosis, inflammatory cytokines and oxidative stress.

Anti-inflammatory and healing effect of the polysaccharidic extract of Opuntia ficus-indica cladodes in cutaneous excisional wounds in rats.

This study aimed to investigate the anti-inflammatory and wound healing effects of the polysaccharide extract from Opuntia ficus-indica cladodes (TPL-Ofi) using a rat cutaneous wound model. After anaesthesia, four 7-mm-diameter dorsal wounds per animal (n = 6/group for each experimental day of evaluation) were created in female Wistar rats using a surgical punch. The animals were treated topically twice daily with TPL-Ofi (0.01-1%; treated group) or sterile saline (control group) for a period of 21 days. Ulcerated tissue was collected for analysis of histological parameters (inflammation score, number of polymorphonuclear, mononuclear, fibroblast/myofibroblasts and blood vessels), immunohistochemical (fibroblast growth factor 2 [FGF-2]) and oxidative stress markers (myeloperoxidase [MPO] and glutathione [GSH]). After 21 days of treatment, body weight, net organ weight and plasma biochemical levels were measured. TPL-Ofi, containing a total carbohydrate content of 65.5% and uronic acid at 2.8%, reduced oedema on the second day and increased the nociceptive threshold on the second and third days. TPL-Ofi reduced mononuclear infiltrate on the second and MPO activity on the fifth day. TPL-Ofi increased GSH levels on the second day, as well as fibroblast/myofibroblasts counts, neoangiogenesis and FGF-2 levels on the fifth and seventh days. No changes were observed in body weight, net organ weight or toxicology assessment. Topical application of TPL-Ofi exhibited anti-inflammatory and antinociceptive effects, ultimately improving wound healing in cutaneous wounds.

Polysaccharide extract of Caesalpinia ferrea (Mart) pods attenuates inflammation and enhances the proliferative phase of rat cutaneous wounds.

Pods of Caesalpinia ferrea, popularly used to treat inflammatory processes, were collected to obtain the polysaccharide-rich extract, presenting anti-inflammatory and antinociceptive effects in acute inflammation models. This study aimed to evaluate the anti-inflammatory, antinociceptive and healing activities of the polysaccharide-rich extract from Caesalpinia ferrea pods (PEp-Cf) in the rat model of cutaneous excisional wound. PEp-Cf (0.025-0.1%) or 0.9% NaCl was topically applied in the wounds at dorsal thoracic region (2×/day) during 21 days for measurement of clinical signs (hyperemia, inflammatory exudate, edema, nociception), wound size, histopathological/histomorphometric, oxidative/inflammatory markers and systemic toxicity. PEp-Cf at 0.1% reduced wound area and increased ulcer contraction [days 2 and 10 (21-78%)]. PEp-Cf reduced clinical signs [days 2 and 5 (2.2-2.8×)] and modulated the healing inflammatory phase via stimulation of epithelialization (days 10 and 14), and inhibition of polymorphonuclears [days 2 and 5 (71-74%)], protein leakage [days 2 and 5 (28-41%)], nitrate [days 2 and 5 (2.2-6×)] and malondialdehyde [days 2 and 5 (46-49%)]. PEp-Cf increased the number of blood vessels [days 5 and 7 (3.1-9.6×)], fibroblasts [days 5 and 7 (2.1-6.4×)] and collagen [days 5 to 14 (1.5-1.8×)]. In conclusion, the topical application of PEp-Cf at 0.1% accelerates the healing process of rat cutaneous wounds via modulation of the inflammatory and proliferative phases, being devoid of systemic alterations.

Structural characterization of anticoagulant and antithrombotic polysaccharides isolated from Caesalpinia ferrea stem barks.

This study aimed to isolate, characterize chemical-structurally and evaluate the effects of polysaccharides from Caesalpinia (Libidibia) ferrea stem barks in the haemostatic system. The deproteinated-polysaccharide extract (PE-Cf) after being fractionated by ion exchange chromatography-DEAE-cellulose resulted in three fractions (FI, FII, FIII) containing total carbohydrates (14.3-38%), including uronic acid (5-16%), and polyphenols (0.94-1.7 mg/g GAE). The polysaccharide fractions presented polydisperse profile in polyacrylamide gel electrophoresis (detected by Stains-All) and molecular masses (9.5 × 104 Da-1.5 × 105 Da) identified by gel permeation chromatography. FT-IR showed absorption bands (1630 cm-1, 1396-1331 cm-1), indicative of uronic acid, and a band at 1071 cm-1, typical of COO- groups of galacturonic acid. The NMR spectra of C. ferrea polysaccharides revealed a central core composed mainly by 5-linked α-Araf and minority components as α-Rhap and α-GalAp. UV spectra of fractions revealed discrete shoulders at 269-275 nm, characteristic of polyphenolic compounds. In vitro, polysaccharides inhibited the intrinsic and/or common coagulation pathway (aPTT test) (2.0-3.7 fold) and the platelet aggregation induced by 3 µM adenosine diphosphate (25-48%) and 5 µg/mL collagen (24%), but not that induced by arachidonic acid. In vivo, the polysaccharides inhibited (36-69%) venous thrombosis induced by hypercoagulability and stasis, showing discrete hemorrhagic effect. In conclusion, the polysaccharides of C. ferrea barks, containing arabinose, galactose, rhamnose and uronic acid, possess anticoagulant, antiplatelet and antithrombotic properties of low hemorrhagic risk, suggesting potential applicability in thromboembolic disorders.

Polysaccaride-rich extract of Caesalpina ferrea stem barks attenuates mice acute inflammation induced by zymosan: Oxidative stress modulation.

ETHNOPHARMACOLOGICAL RELEVANCE: Stem barks of Caesalpinia ferrea Mart. Ex Tul. (Caesalpiniaceae), also known as pau-ferro jucá or jucaína, are popularly used to treat contusions, diabetes, rheumatism and other inflammatory conditions in the form of tea, lick or decoction. OBJECTIVE: To evaluate the effect of the polysaccharide-rich extract obtained from C. ferrea stem barks (PE-Cf) in mice models of acute inflammation induced by zymosan and the involvement of oxidative stress biomarkers. MATERIALS AND METHODS: Mice were treated with PE-Cf (0.001, 0.01, 0.1, 1 mg/kg) by endovenous route (i.v.) or per oral (p.o.) 30 or 60 min before injection of the inflammatory stimuli zymosan (0.5 mg; intraperitoneal or subcutaneous intraplantar). The inflammatory parameters (edema, nociception, leukocyte migration) and oxidative stress markers (myeloperoxidase-MPO, malondialdehyde-MDA, nitrite, reduced glutathione-GSH, glutathione peroxidase-GPx) were evaluated in the models of paw edema (hidropletysmometry/expressed as ml or area under curve-AUC) and peritonitis (optical microscopy/expressed as n° of cells/mm3 of peritoneal fluid). Statistical analysis was performed by ANOVA, followed by Bonferroni test. RESULTS: PE-Cf (0.1, 0.01 and 1 mg/kg) dose-dependently inhibited paw edema, showing maximal effect (74%) at 1 mg/kg in the 5th (52 ± 9.6 µl vs. zymosan: 204 ± 3.6 µl). PE-Cf (1 mg/kg) also inhibited by 43% MPO activity in the paw tissues (17 ± 1 vs. zymosan: 30 ± 2.6 U/mg). Besides, 4 h after peritonitis induction, PE-Cf (1 mg/kg) reduced neutrophil migration by 84% (432 ± 45 vs. zymosan: 2651 ± 643 cells/mm3); visceral nociception by 76% (3 ± 0.6 vs. zymosan: 16 ± 4 writhes); nitric oxide by 73% (0.131 ± 0.033 vs. zymosan: 0.578 ± 0.185 NO2-/NO3-ml); MDA (98 ± 10 vs. zymosan:156 ± 21 U/ml), and increased GSH by 65% (736 ± 65 vs. zymosan: 259 ± 58 µmol/ml) and GPx by 72% (0.037 ± 0.007 vs. zymosan: 0.010 ± 0.005 U/mg protein). CONCLUSION: The polysaccharide-rich extract of Caesalpinia ferrea stem barks present anti-inflammatory and antioxidant effects in mice models of acute inflammation induced by zymosan.

Sulfated polysaccharide from the red algae Gelidiella acerosa: Anticoagulant, antiplatelet and antithrombotic effects.

A sulfated polysaccharide from the red algae Gelidiella acerosa (GaSP) was obtained through enzymatic extraction and subjected to chemical characterization by HPSEC, elemental microanalysis, FT-IR and NMR spectroscopies. The GaSP anticoagulant activity was investigated through APTT and PT tests and platelet aggregation assessed by turbidimetry. The antithrombotic and hemorrhagic activities were evaluated by venous thrombosis and hemorrhagic tendency models, respectively. FT-IR and NMR demonstrated that GaSP is a sulfated agaran. HPSEC and elemental microanalysis revealed a peak molar mass of 284.8 kDa and a degree of sulfation of 0.63, respectively. This molecule prolonged the coagulation time in 2.1 times and inhibited the platelet aggregation by 45%. Furthermore, it showed significant dose-dependent antithrombotic effect of 40%, 64% and 80% at 0.1, 0.5 and 1 mg/kg, respectively, without hemorrhage. These results suggest that GaSP has promising antithrombotic.

Ximenia americana heteropolysaccharides ameliorate inflammation and visceral hypernociception in murine caerulein-induced acute pancreatitis: Involvement of CB2 receptors.

BACKGROUND: This study aimed to investigate and characterize the anti-inflammatory and anti-hypernociceptive effects of the total polysaccharides of X. americana (TPL-Xa) bark in a mouse model of acute pancreatitis-induced by caerulein and the potential involvement of cannabinoid receptors. METHODS: TPL-Xa was characterized by1H and 13C NMR spectroscopy. Animals received TPL-Xa (10 mg/kg, i.v.) 30 min before and after caerulein (50 µg/kg, 10×, i.p.) administration. To evaluate the involvement of cannabinoid receptors, AM281 (3 mg/kg, s.c.) and AM630 (1 mg/kg, s.c.) were administered 30 min before TPL-Xa. Plasma levels of amylase and lipase, pancreatic myeloperoxidase (MPO), histology, visceral hypernociception and motor coordination were evaluated 11 and 24 h after acute pancreatitis (AP) induction. RESULTS: TPL-Xa, containing a heteropolysaccharide composed of glucose, galactose, arabinose, rhamnose, fucose and galacturonic acid, reduced amylase and lipase levels, MPO activity, acinar cell necrosis, edema and neutrophil infiltration. TPL-Xa increased the threshold of visceral hypernociception, an effect reversed by AM630, an antagonist of cannabinoid receptor type 2 (CB2). In addition, TPL-Xa did not alter the animals' motor coordination. CONCLUSIONS: TPL-Xa contains heteropolysaccharides that inhibit inflammation and hypernociception in the experimental model of caerulein-induced AP, by a mechanism involving type CB2 receptors.

The polysaccharide-rich tea of Ximenia americana barks prevents indomethacin-induced gastrointestinal damage via neutrophil inhibition.

ETHNOPHARMACOLOGICAL RELEVANCE: Barks of Ximenia americana are used by the population to treat gastrointestinal inflammatory disorders. Indomethacin is a non-selective non-steroidal anti-inflammatory drug that induces marked gastrointestinal damage. AIMS OF THE STUDIES: To evaluate the gastroprotective activity of total polysaccharides contained in the extract (TPL-Xa) or tea (Tea-Xa) of Ximenia americana barks in the mice gastric damage induced by indomethacin. MATERIALS AND METHODS: TPL-Xa was obtained by a combination of NaOH extraction and ethanol precipitation. Tea-Xa was prepared in distilled water boiled during 5 min. Animals received p.o. 0.9% NaCl (saline - control group), TPL-Xa (1-90 mg/kg) or Tea-Xa 1 h before gastritis induction by indomethacin (20 mg/kg). Mice were sacrificed 7 h after gastritis induction and analyzed for the following parameters: stomach lesions measurement; histological evaluation; myeloperoxidase (MPO) activity; nitrate/nitrite and cytokine levels; leukocyte adhesion and rolling by intravital microscopy. RESULTS: TPL-Xa reduced macroscopic and microscopic damage, MPO activity (59%), leukocyte rolling (86%) and adhesion (84%), nitrite/nitrate ratio (100%) and IL-8 (69%), but increased IL-4 (50%). Tea-Xa (12.8 yield; 39.3% carbohydrate, including 25.8% uronic acid; 4% protein) reduced macroscopic damage (62%) and MPO activity (50%). CONCLUSION: TPL and Tea of Ximenia americana barks ameliorate the gastric injury induced by indomethacin in mice, an effect that was dependent on the reduction of neutrophil infiltration.

The anticonvulsant effect of a polysaccharide-rich extract from Genipa americana leaves is mediated by GABA receptor.

BACKGROUND: This study aimed to chemically characterize a polysaccharide-rich extract (PRE) obtained from Genipa americana leaves and evaluate its neuroprotective effect in the brain morphology and oxidative markers using mice behavioral models. METHODS: Dry powder (5 g) of G. americana leaves were submitted to depigmentation in methanol. PRE was obtained by extraction in NaOH and precipitation with absolute ethanol and characterized by infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 13C NMR). Swiss mice (25-35 g) received saline (0.9% NaCl) or PRE (1-27 mg/kg) by intraperitoneal (i.p.) route, 30 min before evaluation in behavioral models (open field, elevated plus maze, sleeping time, tail suspension, forced swimming, seizures induced by pentylenetetrazole-PTZ). Animal's brain were dissected and analyzed for histological alterations and oxidative stress. RESULTS: FTIR spectrum showed bands around 3417 cm-1 and 2928 cm-1, relative to the vibrational stretching of OH and CH, respectively. 1H NMR spectrum revealed signals at δ 3.85 (methoxyl groups) and δ 2.4 (acetyl) ppm. 13C NMR spectrum revealed signals at δ 108.0 and δ 61.5 ppm, corresponding to C1 and C5 of α-L-arabinofuranosyl residues. PRE presented central inhibitory effect, increasing the latency for PTZ-induced seizures by 63% (9 mg/kg) and 55% (27 mg/kg), and the latency to death by 73% (9 mg/kg) and 72% (27 mg/kg). Both effects were reversed by the association with flumazenil. CONCLUSIONS: PRE, containing a heteropolysaccharide, presents antioxidant and anticonvulsant effect in the model of PTZ-induced seizures via gamma-aminobutyric acid (GABA), decreasing the number of hippocampal black neurons.

Trypanocidal activity of polysaccharide extract from Genipa americana leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: The parts of the Genipa americana (Rubiaceae) tree, also known as "jenipapo" or "jenipapeiro", has been used in traditional Medicine in parasitic and bacterial infections. Thus, the experimental evolution of the antiparasitic activity of polysaccharide extracts from Genipa americana leaves, and correlation with antiparasitic and popular use is important. AIM OF THE STUDY: To evaluate the effect of polysaccharide extract obtained from Genipa americana leaves on all Trypanosoma cruzi (Y strain: benznidazole-resistant) developmental forms, a protozoan that causes Chagas' disease. MATERIALS AND METHODS: An extract rich in polysaccharides was obtained from the leaves of Genipa americana (GaEPL) by associating depigmentation in methanol followed by extraction of polysaccharides in NaOH and precipitation with ethanol. Cytotoxicity to mammalian cells (LLC-MK2) was determined using an MTT assay. Antiparasitic activity was evaluated against epimastigote, trypomastigote and amastigote forms of T. cruzi. Cell-death mechanism was determined in epimastigote forms by flow cytometry analysis after FITC-annexin V (Ax), 7-AAD, and H2DCFDA staining. Striking morphological changes were observed by scanning electron microscope. RESULTS: GaEPL (6.5% yield; 54.6% total carbohydrate; 21.1% uronic acid and 12% protein), inhibited all T. cruzi developmental forms, epimastigotes after periods of 24h (IC50 = 740 ± 0.075µg/mL), 48h (IC50 = 710 ± 0.053µg/mL) and 72h (IC50 = 870 ± 0.052µg/mL) of incubation; trypomastigotes (IC50 = 470 ± 0.082µg/mL) after periods of 24h and intracellular amastigotes (IC50/2 = 235 or IC50 = 470µg/mL) after periods of 24 and 48h of incubation, with no toxicity on LLC-MK2 cells at the used concentrations. Analysis of the possible action mechanism in the parasites suggested cell death by necrosis with the involvement of reactive oxygen species (ROS). The scanning electron microscopy (SEM) confirmed T. cruzi death by necrosis. CONCLUSIONS: GaEPL showed significant activity against the epimastigote, trypomastigote and amastigote forms of T. cruzi, strain Y, suggesting cell death by necrosis with involvement of reactive oxygen species.

Structural studies of a vasorelaxant lectin from Dioclea reflexa Hook seeds: Crystal structure, molecular docking and dynamics.

The three-dimensional structure of Dioclea reflexa seed lectin (DrfL) was studied in detail by a combination of X-ray crystallography, molecular docking and molecular dynamics. DrfL was purified by affinity chromatography using Sephadex G-50 matrix. Its primary structure was obtained by mass spectrometry, and crystals belonging to orthorhombic space group P212121 were grown by the vapor diffusion method at 293K. The crystal structure was solved at 1.765Å and was very similar to that of other lectins from the same subtribe. The structure presented Rfactor and Rfree of 21.69% and 24.89%, respectively, with no residues in nonallowed regions of Ramachandran plot. Similar to other Diocleinae lectins, DrfL was capable of relaxing aortic rings via NO induction, with CRD participation, albeit with low intensity (32%). In silico analysis results demonstrated that DrfL could strongly interact with complex N-glycans, components of blood vessel glycoconjugates. Despite the high similarity among Diocleinae lectins, it was also reported that each lectin has unique CRD properties that influence carbohydrate binding, resulting in different biological effects presented by these molecules.

Polysaccharide extract of Mimosa tenuiflora stem barks stimulates acute inflammatory response via nitric oxide / Extrato polissacarídico oriundo das cascas do caule de Mimosa tenuiflora induz resposta inflamatória aguda via óxido nítrico

Mimosa tenuiflora (Mimosaceae) or "jurema-preta" is well distributed in the northeast Brazil, being popularly used to treat skin lesions, burns and inflammation. The healing effect of the alcoholic extract prepared with its barks corroborates the popular use. This study aimed to evaluate the inflammatory response of polysaccharides extracted from M. tenuiflora barks (EP-Mt) by methanol/NaOH and ethanol precipitation. Inflammatory activity was assessed in rat models of acute inflammation (paw edema and peritonitis), by the following parameters: edema, vascular permeability, leukocyte migration, myeloperoxidase activity and pharmacological modulation of nitric oxide and prostaglandins. EP-Mt presented 3.8% yield, 41% carbohydrate and 0.34% protein. EP-Mt (0.01, 0.1, 1.0 mg kg-1) injected by subcutaneous route elicited paw edema that lasted from 30-420 min, with maximal effect at 1 mg kg-1 (40x vs. saline), and was inhibited by L-NAME (52%) and dexamethasone (26%). EP-Mt (1 mg kg-1, via intraperitoneal) stimulated leukocytes migration (2.2x), mainly neutrophils (6.5x) and MPO activity (96%). The leukocyte migration elicited by EP-Mt was inhibited by dexamethasone (39%) and L-NAME (38%). EP-Mt containing high carbohydrate content induces acute inflammation via nitric oxide, which open perspectives of application in pathological conditions of immunosuppression.

Mimosa tenuiflora (Mimosaceae) ou "jurema-preta", amplamente distribuída no nordeste brasileiro, é utilizada popularmente no tratamento de lesões de pele, queimaduras e inflamação. O efeito cicatrizante do extrato alcoólico de suas cascas corrobora o uso popular. Avaliou-se o efeito inflamatório dos polissacarídeos da casca de M. tenuiflora (EP-Mt), obtidos por extração com metanol/NaOH e precipitação com etanol. O efeito inflamatório foi avaliado em modelos agudos em ratos (edema de pata, peritonite) por meio dos seguintes parâmetros: edema, permeabilidade vascular, migração leucocitária, atividade da mieloperoxidase e modulação farmacológica de prostaglandinas e óxido nítrico. EP-Mt apresentou 3,8% de rendimento, 41% de carboidratos totais e 0,34% de proteína. EP-Mt (0,01, 0,1, 1,0 mg kg -1), administrado por via subcutânea, induziu edema de pata com duração de 30 a 420 min e efeito máximo na dose de 1 mg kg-1 (40x vs. salina), o qual foi inibido por L-NAME (52%) e dexametasona (26%). EP-Mt (1 mg kg-1, via intraperitoneal) estimulou a migração de leucócitos (2,2x vs. salina), principalmente de neutrófilos (6,5x), com aumento da atividade da mieloperoxidase (96%). A migração de leucócitos foi inibida por dexametasona (39%) e L-NAME (38%). EP-Mt contendo elevado teor de carboidratos induz inflamação aguda via óxido nítrico com perspectivas de aplicação em condições patológicas de imunossupressão.

Novel Pharmacological Properties of Dinoponera quadriceps Giant Ant Venom.

The South American giant ant, Dinoponera quadriceps (Hymenoptera, Formicidae, Ponerinae), produces proteinaceous venom that has antinociceptive, neuroprotective and antimicrobial effects, thereby supporting the popular use of these ants to treat asthma, rheumatism, earache and back pain. Anticoagulant activity is another biological property that has been shown for the venom of other hymenopteran species, like wasps. The aim of this study was to assess the anti-inflammatory, anticoagulant and antiplatelet properties of D. quadriceps venom (DqV). DqV anti-inflammatory activity was assessed by intravenous administration in Swiss mice in the models of paw edema and peritonitis. In vitro, DqV was assessed in coagulation (activated partial thromboplastin time) and platelet aggregation tests. DqV inhibited (27-33%) the edema elicited by carrageenan and the leucocyte migration (43%) elicited by zymosan. DqV decreased by 57% and 42%, respectively, the content of malondialdehyde and nitrite in the peritoneal fluid. DqV prolonged (1.8x) the clotting time and decreased (27%) the platelet aggregation induced by adenosine diphosphate. The crude venom of D. quadriceps presents an anti-inflammatory effect in mice and in vitro anticoagulant and antiplatelet effects.

Inhibition of coagulation proteases and thrombosis and sub-chronic toxicological study of a sulfated polysaccharidic fraction from the red alga Gelidiella acerosa / Inibição de proteases da coagulação e trombose e estudo toxicológico subcrônico de uma fração polissacarídica sulfatada da alga vermelha Gelidiella acerosa

Metabolites isolated from Gelidiella species (Rhodophyta) have been few studied. We evaluated a sulfated polysaccharidic fraction from G. acerosa collected from two Brazilian beaches on the northwestern coast of Brazil (Flecheiras-F and Pedra Rachada-PR) on coagulation proteases and thrombosis. Their toxicity in vivo was also assessed. Enzymatic extractions yielded 1.40%, and similar chromatographic profiles (DEAE-cellulose) were obtained, with fractions (Ga-I→V) containing differences among the relative proportions of sulfate (5-42%), and revealing charge density patterns by electrophoresis. Ga-IV-PR had a discrete effect (3.01 IU mg-1) on normal human coagulation compared with heparin (193 IU mg-1) and was tested on coagulation proteases (thrombin and factor Xa) in the presence of antithrombin and in a model of venous thrombosis in rats using thromboplastin as the thrombogenic stimulus. The systems were inhibited; but at higher doses (>1.0 mg kg-1), this fraction reverted the antithrombotic effect. Regarding the toxicological study, consecutive Ga-IV (9 mg kg-1) for 14 days did not cause mortality in mice, but some biochemical and hematological parameters were discretely altered. Histopathological analysis revealed that increased liver and spleen sizes had no toxicological significance. Therefore, G. acerosa does not biochemically change its matrix polysaccharide composition and proved to be safe antithrombotic agent.

Poucos estudos mostram metabólitos isolados de rodofíceas de espécies Gelidiella. Avaliou-se uma fração polissacarídica sulfatada de G. acerosa coletada a partir de duas praias brasileiras do Nordeste do Brasil (Flecheiras-F e Pedra Rachada-PR) sobre proteases da coagulação e trombose, e em ensaio de toxicidade in vivo. Extrações enzimáticas renderam 1,40% e foram obtidos perfis cromatográficos semelhantes (DEAE-celulose), apresentando frações (Ga-I→V), contendo diferenças entre as proporções relativas de sulfato (5-42%), além de a eletroforese revelar diferenças na densidade de carga. A Ga-IV-PR apresentou discreto efeito (3,01 UI mg-1) sobre a coagulação humana normal comparada à heparina (193 UI mg-1) e foi testada sobre proteases da coagulação (trombina e fator Xa) na presença de antitrombina e em um modelo de trombose venosa em ratos usando tromboplastina com estímulo trombogênico, sendo inibidos esses sistemas. Entretanto, em elevadas doses (>1,0 mg kg-1) o efeito antitrombótico foi revertido. No estudo toxicológico, Ga-IV (9 mg kg-1) consecutiva durante 14 dias não causou mortalidade em camundongos, mas alterou discretamente alguns parâmetros bioquímicos e hematológicos. O aumento nos tamanhos do fígado e baço não apresentou significância toxicológica, segunda análise histopatológica. Portanto, G. acerosa não muda bioquimicamente a composição de polissacarídeo de sua matriz e detém agente antitrombótico seguro.

Vasorelaxant activity of Canavalia grandiflora seed lectin: A structural analysis.

Lectins are comprised of a large family of proteins capable of the specific and reversible recognition of carbohydrates. Legume lectins, the most studied plant lectins, show high structural similarity, but with modifications that imply a variation in the intensity of some biological activities. In this work, the primary and tertiary structures of Canavalia grandiflora (ConGF) were determined. ConGF, a lectin isolated from C. grandiflora seeds, is able to induce relaxant activity in rat aortic rings. The complete sequence of ConGF comprises 237 amino acids. This particular protein has primary sequence variations commonly found in lectins from Dioclea and Canavalia genera. The protein structure was solved at 2.3 Å resolution by X-ray crystallography. An X-Man molecule was modeled into the carbohydrate recognition domain. Still, ConGF (30 and 100 µg mL(-1)) elicited 25% of vasorelaxation (IC50=34.48 ± 5.07 µg mL(-1)) in endothelialized aortic rings. A nonselective inhibitor of nitric oxide blocked ConGF relaxant effect, showing mediation by nitric oxide. Key distances between ConGF carbohydrate recognition domain residues were determined in order to explain this effect, in turn revealing some structural aspects that could differentiate lectins from the Canavalia genera with respect to different efficacy in vasorelaxant effect.

Edematogenic activity of a sulfated galactan from the red marine algae Gelidium crinale.

CONTEXT: The red algae Gelidium crinale (Turner) Gaillon (Gelidiaceae), encountered along the Southeast and Northeast Brazilian sea coast, contains a sulfated galactan presenting a similar saccharide backbone compared to λ carrageenan. Inflammatory effects of other galactans were reported, but not for that obtained from G. crinale (SG-Gc). OBJECTIVE: To investigate the in vivo edematogenic effect of SG-Gc in comparison to λ carrageenan. METHODS: SG-Gc was isolated by ion exchange chromatography. Paw edema was induced by subcutaneous (s.c.) intraplantar injection of SG-Gc or λ carrageenan and evaluated by hydroplethysmometry. Data were expressed as the increase in paw volume subtracted from the basal volume or area under curve-AUC. To investigate the participation of early and late-phase inflammatory mediators, rats were treated with pyrilamine, compound 48/80, indomethacin, NG-nitro-L-arginine methyl ester (L-NAME), or pentoxifylline before SG-Gc. RESULTS: SG-Gc edematogenic effect was initiated at 0.5 h, peaked at 2 h (1.26 ± 0.05 mL) and lasted until 6 h (0.21 ± 0.03 mL), whereas the carrageenan-induced edema started at 1 h. The first phase (1-3 h) of SG-Gc-induced edema was 176 ± 15 (AUC) versus carrageenan (114.5 ± 14), whereas the second phase (3-5 h) was 95 ± 12 (AUC) versus carrageenan (117.5 ± 11). Treatment with compound 48/80, pyrilamine, indomethacin, L-NAME, and pentoxifylline inhibited the effect of SG-Gc by 32, 40, 69, 72, and 49%, respectively. DISCUSSION AND CONCLUSION: SG-Gc and λ carrageenan induce different profile of inflammatory response in the paw edema model, that involves histamine, cytokines, prostaglandins, and nitric oxide (NO), but with different degree of participation.

Polysaccharide fractions of Caesalpinia ferrea pods: potential anti-inflammatory usage.

ETHNOPHARMACOLOGICAL RELEVANCE: Caesalpinia ferrea (Caesalpinioideae), known as pau-ferro or juca, has been used in the traditional medicine in North and Northeast of Brazil in inflammatory disorder, among others. Thus, experimental evaluation of the anti-inflammatory activity of extracts and fraction polysaccharides of Caesalpinia ferrea pods, and correlation with its anti-inflammatory activity and popular use is important. MATERIALS AND METHODS: Total polysaccharides (TPL) were applied to ion exchange chromatography and eluted stepwise. Paw edema was induced s.c. by λ-carrageenan, dextran, histamine, serotonin, compound 48/80, bradykinin, prostaglandin E(2) (PGE(2)) or L-arginine and analyzed by plethysmometry and protein leakage by spectrophotometry. Peritonitis was induced i.p. by carrageenan or N-formyl-methionyl-leucyl-phenylalanine (fMLP) and analyzed 4 h later for leukocyte migration and protein leakage. Animals were treated i.v. with TPL or polysaccharide fractions (0.01, 0.1, 1 mg/kg) 30 min before stimuli in both models. Toxicity (variation of body/organ mass and hematological/biochemical parameters) was evaluated after the seven-day treatment with the most active polysaccharide fraction (1 mg/kg; i.v.). RESULTS: Chromatography of TPL (2.8% yield) provided three major polysaccharide fractions (FI, FII, FIII). At 1 mg/kg, TPL inhibited the paw edema induced by carrageenan (60%) and FIII (fraction presenting high carbohydrate and low protein content) inhibited the inflammatory parameters in the paw edema induced by the following stimuli: carrageenan (70%), dextran (53%), histamine (65%), serotonin (62%), bradykinin (60%), PGE(2) (63%), nitric oxide (61%) and compound 48/80 (36%). Additionally, FIII at 1 mg/kg inhibited the carrageenan-induced edema in animals with intact mast cells, but only the late phase of those with degranulated mast cells elicited by compound 48/80. Moreover, FIII inhibited cell migration and protein leakage in the model of peritonitis elicited by carrageenan (88%) and fMLP (64%), being well tolerated by animals. CONCLUSIONS: Extracts and polysaccharide fractions of Caesalpinia ferrea pods exhibit potent anti-inflammatory activity via negative modulation of histamine, serotonin, bradykinin, PGE(2) and NO released in the carrageenan-induced edema, showing involvement of mast cells. FIII could be interfering not only in the vascular, but also in cellular inflammatory events, revealing to be an important active component of traditionally prepared remedies used to treat inflammatory states.