Objective
Wide biotechnological investigations of only a limited number of seaweed lectins have been performed. We previously demonstrated the anti-nociceptive and anti-inflammatory effects of a ...lectin isolated from the green seaweed
Caulerpa cupressoides
var.
lycopodium
(CcL). Herein, we further studied the mechanisms of action of CcL.
Methods
Classical acute inflammation models induced by different flogistic agents were used to evaluate the anti-inflammatory action of CcL. CcL was injected locally into the rat paw to verify a possible pro-inflammatory outcome.
Results
CcL (0.1, 1 or 10 mg/kg; i.v.) reduced the carrageenan-induced rat paw edema and neutrophilic infiltration, which was not altered by either mucin (inhibitor of CcL carbohydrate-binding site) or ZnPP-IX (specific HO-1 inhibitor). Immunohistochemical analyses showed that CcL (1 mg/kg) reduced the expression of the cytokines IL-1β, TNF-α, IL-6 and COX-2. CcL (0.1, 1 or 10 mg/kg) inhibited dextran, and CcL (1 mg/kg) inhibited histamine-induced rat paw edema. Both effects were reversed by mucin inhibition. CcL (1 mg/kg) was ineffective for the treatment of serotonin- and bradykinin-induced rat paw edema. When injected via the i.pl. route, CcL (10 mg/kg) elicited rat paw edema involving a wide range of mediators.
Conclusions
The anti-inflammatory action of CcL involves the inhibition of IL-1β, TNF-α, IL-6 and COX-2 expression and histamine H
1
receptors. When locally administered, CcL exerts pro-inflammatory actions.
Red algae sulfated polysaccharides (SPs) have been widely described as anticoagulant and antithrombotic agents; however no description of antithrombotic activity regarding green algae SPs has been ...reported. Caulerpa cupressoides (Chlorophyta) has three different SPs fractions (SP1, SP2 and SP3). We investigated the effects of SP2 on thrombin activity by antithrombin and in an experimental model of venous thrombosis in rats. The inhibition of thrombin assay was evaluated using antithrombin (AT) in the presence of SP2 and the antithrombotic activity was investigated in rats with thromboplastin as the thrombogenic stimulus. The anticoagulant effects of SP2 are suggested be due to the potentiation of thrombin inhibition by antithrombin (IC50 ~ 10.0µg mL-1) and this mechanism of interaction is different when compared to other studied Caulerpa polysaccharides. SP2 exhibited antithrombotic effects at doses of 1.0 and 2.0mg kg-1 body weight, but at higher doses (>2.0mg kg-1 body weight) this polysaccharide revert the antithrombotic property. No hemorrhagic effect (2.0mg kg-1) was observed. As occurs with red algae SPs, these results indicate that green algae SPs are also capable of exhibiting different in vivo properties.
Os polissacarídeos sulfatados (PSs) de algas vermelhas têm sido relatados mundialmente como agentes anticoagulantes e antitrombóticos. Entretanto, nenhuma descrição de atividade antitrombótica tem sido relacionada com os PSs de algas verdes. A clorofícea Caulerpa cupressoides possui três frações de PSs (PS1; PS2 e PS3). Dessa forma, objetivou-se investigar os efeitos da fração PS2 sobre a atividade da trombina por antitrombina e usando um modelo experimental de trombose venosa em ratos. O ensaio de inibição da trombina foi avaliado usando a antitrombina (AT) na presença de PS2 e a atividade antitrombótica foi investigada em ratos, usando a tromboplastina como o estímulo trombogênico. Os efeitos anticoagulantes de PS2 devem-se provavelmente à sua potência de inibir a trombina mediada pela AT (IC50 ~ 10,0µg mL-1) e esse mecanismo de interação é diferente, comparado ao de outros polissacarídeos de Caulerpa estudados. PS2 exibiu efeitos antitrombóticos nas doses de 1,0 e 2,0mg kg-1 peso corpóreo, mas em doses mais elevadas (>2,0mg kg-1 peso corpóreo) esse polissacarídeo exibe efeitos pró-trombóticos. Também não foi observado nenhum efeito hemorrágico (2,0mg kg-1). Assim como ocorre com os PSs de algas vermelhas, os resultados indicam que os PSs de algas verdes também possuem atividades biológicas distintas in vivo.
The aim of this work was to study the effect of Halymenia floresia (Hf) on duodenum contractility, and on experimental protocols of gastric compliance (GC) in rats. Fraction Hf2s exhibited a ...concentration-dependent myocontractile effect (EC50 12.48 µg/ml), and an inhibitory effect after consecutive washing. The contractile response promoted by Hf2s in the duodenum strips was completely inhibited by verapamil, and the effects were prevented in the presence of Ca2+-free medium. The pretreatment with atropine prevented the Hf2s myocontractile effect. Hf2s was also capable to decrease the GC (from 3.8±0.06 to 3.4±0.13 ml, P<0.05), which did not return to basal levels after more 50 min of observation. These results indicated that the algal polysaccharide possessed in vitro and in vivo gastrointestinal effects.
Background
Acute pancreatitis is characterized by inflammatory processes affecting not only the pancreas, but also the lung. Here, we investigated timing of leucocyte infiltration and chemokine ...expression within lung and pancreas during pancreatitis and whether treatments selectively inhibiting chemokines (using Evasins) could improve organ injury.
Material and methods
C57Bl/6 mice were submitted in vivo to 10‐h intraperitoneal injections of cerulein and followed for up to 168 h. Five minutes after the first cerulein injection, a single intraperitoneal injection of 10 μg Evasin‐3, 1 μg Evasin‐4 or an equal volume of vehicle (PBS) was performed. Leucocytes, reactive oxygen species (ROS), necrosis and chemokine/cytokine mRNA expression were assessed in different organs by immunohistology and real‐time RT‐PCR, respectively.
Results
In the lung, neutrophil infiltration and macrophage infiltration peaked at 12 h and were accompanied by increased CXCL2 mRNA expression. CCL2, CXCL1 and TNF‐alpha significantly increased after 24 h as compared to baseline. No increase in CCL3 and CCL5 was observed. In the pancreas, neutrophil infiltration peaked at 6 h, while macrophages increased only after 72 h. Treatment with Evasin‐3 decreased neutrophil infiltration, ROS production and apoptosis in the lung and reduced neutrophils, macrophages apoptosis and necrosis in the pancreas. Evasin‐4 only reduced macrophage content in the lung and did not provide any benefit at the pancreas level.
Conclusion
Chemokine production and leucocyte infiltration are timely regulated in lung and pancreas during pancreatitis. CXC chemokine inhibition with Evasin‐3 improved neutrophil inflammation and injury, potentially interfering with damages in acute pancreatitis and related pulmonary complications.
The structural complexity of the agaran type-sulfated polysaccharides (SPs) found in Acanthophora muscoides limits its investigation as anticoagulant alternative to heparin which induces clot ...complications. This study was extended to evaluate the properties of a SPs fraction and its alkali/desulfated derivatives on an intrinsic pathway-induced thrombin generation (TG) continuous model using 60-fold diluted normal or serpins-depleted human plasma. 0.75 M NaCl-eluted SPs fraction by DEAE-cellulose chromatography containing sulfate (35.20%), total sugars (55.97%) and no proteins showed charge homogeneity and heterogeneous molecular weight by agarose/polyacrylamide gel electrophoresis, respectively, using sequential staining with toluidine blue and Stains-All. Fourier Transform Infrared spectroscopy confirmed agaran-structure. Intact fraction poorly acted on the activated partial thromboplastin time (3.10 IU) than heparin (193 IU), but there was a preponderance of the serpin-independent effect than serpin-dependent one in TG assay comparing both systems was continually recorded. Heparin abolished plasma TG, but was inactive in depleted human plasma. While desulfated derivative of the respective fraction anticipated and induced thrombin formation vs. untreated plasma. The results suggested that sulfated sugars residues in the sacharide units of the polymer appear to be important to attenuate TG in vitro.
Abstract Experimental data from animal models and clinical studies support connections between the haemostasis and inflammation in atherogenesis. These interfaces among inflammation and ...thrombogenesis have been suggested as targets for pharmacological intervention to reduce disease progression. We hypothesize that the recently discovered antithrombotic drug Sulphated Galactan (SG) (isolated from the red marine alga Acanthophora muscoides ) might reduce atherosclerotic plaque vulnerability and inflammatory gene expression in 10-week aged apolipoprotein E deficient (ApoE −/−) mice under high-cholesterol diet for additional 11 weeks. Then, the underlying cellular mechanisms were investigated in vitro. SG (10 mg/kg) or Vehicle was subcutaneously injected from week 6 until week 11 of the diet. Treatment with SG reduced intraplaque macrophage and Tissue Factor (TF) content as compared to Vehicle-treated animals. Intraplaque TF co-localized and positively correlated with macrophage rich-areas. No changes on atherosclerotic plaque size, and other intraplaque features of vulnerability (such as lipid, neutrophil, MMP-9 and collagen contents) were observed. Moreover, mRNA expression of MMPs, chemokines and genetic markers of Th1/2/reg/17 lymphocyte polarization within mouse aortic arches and spleens was not affected by SG treatment. In vitro, treatment with SG dose-dependently reduced macrophage chemotaxis without affecting TF production. Overall, the chronic SG treatment was well tolerated. In conclusion, our results indicate that SG treatment reduced intraplaque macrophage content (by impacting on cell recruitment) and, concomitantly, intraplaque TF content of potential macrophage origin in atherosclerotic mice.
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