The aim of this study was to determine the yield, chemical composition, specific rotation (SR), infrared (IR) spectroscopy and the effect on bacterial growth of a crude sulfated polysaccharide (SP) from the red marine alga G. ornata (Go). Go-1 (25°C), Go-2 (80°C), and Go-3 (80°C) were sequentially extracted and yielded 9.2%. The contents of sulfate (5.88-10.3%) and proteins (0.1-3.7%) were small. The values of SR were [µ]D20°f -19.0, -51.0, and -56.5, respectively. IR spectrums showed the presence of galactose-4 sulfate and absence of 3,6-anydrogalactose-2 sulfate, galactose-6 sulfate and galactose-2 sulfate. SR and IR techniques confirmed SPs. Go-3 was tested on the growth of bacteria (Bacillus subtilis, Staphylococcus aureus, Enterobacter aerogens, Escherichia coli, Pseudomonas aeruginosa, Salmonela choleraesuis and Salmonela typhi), but only E. coli was inhibited.

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.

Objetivou-se isolar, fracionar e avaliar a toxicidade in vivo dos polissacarídeos sulfatados (PSs) da rodofícea Hypnea musciformis, quando obtidos por três métodos de extração (M I; M II e M III). Os PSs foram extraídos com papaína em tampão acetato de sódio 100mM (pH 5,0), contendo cisteína e EDTA (5mM) (M I) ou água (25-80°C (M II); 80°C (M III)) e, em seguida, determinados sua composição química de carboidratos totais, sulfato livre (SL) e proteínas contaminantes (PCs). Os PSs foram submetidos à cromatografia de troca iônica (DEAE-celulose) usando um gradiente de cloreto de sódio, sendo avaliado o grau de homogeneidade e densidade de carga por eletroforese em gel de agarose das frações obtidas e comparadas à heparina. O ensaio in vivo foi realizado em grupos (n=6) de camundongos Swiss machos e fêmeas (24-33g), os quais receberam: PSs (9mg kg-1; i.p.) isentos do PCs (M I) e salina 0,9% (0,1mL 10g-1; i.p.), durante 14 dias consecutivos. No 15o dia, os animais foram anestesiados e sacrificados para coletas de sangue e órgãos, os quais foram utilizados para dosagens bioquímicas e correlações com suas massas corpóreas, respectivamente. O teor de SL (31,05±0,53%) (P<0,05) e o fracionamento, em DEAE-celulose, indicaram o M I mais eficiente na obtenção de PSs, comparado ao M II e M III. Os animais mostraram-se tolerantes aos PSs do M I e não se observou alteração de ordem hepática ou renal (P>0,05).

This study aimed to isolate, fractionate and evaluate the in vivo toxicity of sulfated polysaccharides (SPs) from Hypnea musciformis (Rhodophyta), when obtained by three extraction methods (M I, M II and M III). SPs were extracted with papain in 100mM sodium acetate (pH 5.0) containing cysteine and EDTA (5mM) (M I) or water (25-80°C (M II), 80°C (M III)), and then their chemical composition of total carbohydrates, free sulfate (FS) and contaminant proteins (CPs) was determined. SPs were submitted to ion-exchange chromatography (DEAE-celulose) using a sodium chloride gradient, being the degree of homogeneity and charge density evaluated by agarose gel electrophoresis of the fractions obtained and compared to heparin. The in vivo assay was performed using groups (n=6) of male and female Swiss mice (24-33g), which received: SPs (9mg kg-1, i.p.) absence of CPs (M I) and 0.9% saline (0.1mL 10g-1, i.p.), for 14 consecutive days. On the 15th day, collect blood and organs for biochemical dosages and corporal mass correlation, respectively, from the animals anesthetized and sacrificed were performed. The sulfate content of FS (31.05±0.53%) (P<0.05) and the fractionation by DEAE-cellulose showed M I more effectiveness in obtaining SPs compared to M II and M III. The animals were tolerable to SPs from M I, and it wasn't observed hepatic or renal alteration (P>0.05)

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.

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.