Chemoprotective effects of Ulva lactuca (green seaweed) aqueous-ethanolic extract against subchronic exposure to benzo(a)pyrene by CYP1A1 inhibition in mice.

The protective effect of the supplementation with an aqueous-ethanolic extract obtained from Ulva lactuca (Delile) green seaweed on benzo[a] pyrene-induced damage in mice was evaluated. Animals were treated with oral doses of U. lactuca extract (100 and 400 mg/kg) for 9 weeks. They were exposed to 50 mg/kg of oral doses of benzo(a)pyrene starting from the second week and up to the fifth week. Groups treated with benzo(a)pyrene only (second to fifth weeks), sunflower oil (vehicle, 9 weeks), or U. lactuca extract (100 and 400 mg/kg, 9 weeks) were also included in the study. The treatment with 400 mg/kg of the extract ameliorated the oxidative damage, decreased IL-1ß and TNF-α levels, and favorably regulated the antioxidant defenses compared with benzo(a)pyrene-exposed group. The benzo(a)pyrene-induced DNA damage was also reduced, as it was evidenced by the lower micronucleus formation in U. lactuca extract-supplemented animals. The extract protected the hepatic tissue, and it reduced the liver activity/expression of CYP1A1. These results altogether suggested a chemoprotective effect of U. lactuca extract against benzo(a)pyrene-induced-toxicity in mice, probably associated with an inhibitory effect of carcinogen bioactivation.

Fed-batch cultivation with CO2 and monoethanolamine: Influence on Chlorella fusca LEB 111 cultivation, carbon biofixation and biomolecules production.

The aim of this study was to evaluate the interaction between the periodic addition of monoethanolamine (MEA) and CO2 during the cultivation of Chlorella fusca LEB 111. For this purpose, MEA has been added in abiotic assays, followed by fed-batch cultures with that green alga and the absorbent. BG-11 medium shown a higher potential of CO2 absorption with MEA addition, and the bicarbonate was the chemical species of carbon prevailing in the chemical equilibrium. The periodic addition of MEA did not reduce the kinetics of growth, promoted a higher accumulation of DIC (81.4 mg L-1) in the medium and protein (44.0% w w-1) and lipid (30.8% w w-1) concentrations in the biomass of C. fusca LEB 111. Therefore, it was demonstrated that fed-batch culture with MEA increased CO2 fixation and the biomolecule synthesis as proteins and lipids.

Sulfated Polysaccharides in the Freshwater Green Macroalga Cladophora surera Not Linked to Salinity Adaptation.

The presence of sulfated polysaccharides in cell walls of seaweeds is considered to be a consequence of the physiological adaptation to the high salinity of the marine environment. Recently, it was found that sulfated polysaccharides were present in certain freshwater Cladophora species and some vascular plants. Cladophora (Ulvophyceae, Chlorophyta) is one of the largest genera of green algae that are able to grow in both, seas and freshwater courses. Previous studies carried out on the water-soluble polysaccharides of the marine species C. falklandica established the presence of sulfated xylogalactoarabinans constituted by a backbone of 4-linked ß-L-arabinopyranose units partially sulfated mainly on C3 and also on C2 with partial glycosylation, mostly on C2, with terminal ß-D-xylopyranose or ß-D-galactofuranose units. Besides, minor amounts of 3-, 6- and/or 3,6-linked ß-D-galactan structures, with galactose in the pyranosic form were detected. In this work, the main water soluble cell wall polysaccharides from the freshwater alga Cladophora surera were characterized. It was found that this green alga biosynthesizes sulfated polysaccharides, with a structure similar to those found in marine species of this genus. Calibration of molecular clock with fossil data suggests that colonization of freshwater environments occurred during the Miocene by its ancestor. Therefore, the presence of sulfated polysaccharides in the freshwater green macroalga C. surera could be, in this case, an adaptation to transient desiccation and changes in ionic strength. Retention of sulfated polysaccharides at the cell walls may represent a snapshot of an evolutionary event, and, thus constitutes an excellent model for further studies on the mechanisms of sulfation on cell wall polysaccharides and environmental stress co-evolution.

Infecção disseminada por Chlorella sp. em um ovino / Disseminated infection by Chlorella sp. in a sheep

Descreve-se um caso de infecção disseminada por Chlorella sp. em um ovino, na região semiárida da Paraíba, Brasil. O animal apresentou emagrecimento e aumento de volume abdominal há um mês. Na necropsia, foram observados nódulos esverdeados em fígado, pulmões, intestino e linfonodos. Histologicamente, os nódulos correspondiam a piogranulomas com miríades de algas intralesionais. Provavelmente, a infecção tenha ocorrido em consequência do consumo de água estagnada ou capim que tinha sido cortado em uma área irrigada, que são condições frequentes no período da seca na região semiárida.(AU)

A case of disseminated infection by Chlorella sp. is reported in a sheep in semiarid region of Paraíba, northeastern Brazil. The animal showed weight loss and abdominal distension. At necropsy greenish nodules were observed in liver, lung, intestine and lymph nodes. Histologically the nodules corresponded to pyogranulomas with myriad of intralesional algae. Probably the infection occurred as a result of the consumption of stagnant water or grass which had been cut in an irrigated area, conditions that are common in the dry season in the semiarid region.(AU)

Infecção disseminada por Chlorella sp. em um ovino / Disseminated infection by Chlorella sp. in a sheep

Descreve-se um caso de infecção disseminada por Chlorella sp. em um ovino, na região semiárida da Paraíba, Brasil. O animal apresentou emagrecimento e aumento de volume abdominal há um mês. Na necropsia, foram observados nódulos esverdeados em fígado, pulmões, intestino e linfonodos. Histologicamente, os nódulos correspondiam a piogranulomas com miríades de algas intralesionais. Provavelmente, a infecção tenha ocorrido em consequência do consumo de água estagnada ou capim que tinha sido cortado em uma área irrigada, que são condições frequentes no período da seca na região semiárida.

A case of disseminated infection by Chlorella sp. is reported in a sheep in semiarid region of Paraíba, northeastern Brazil. The animal showed weight loss and abdominal distension. At necropsy greenish nodules were observed in liver, lung, intestine and lymph nodes. Histologically the nodules corresponded to pyogranulomas with myriad of intralesional algae. Probably the infection occurred as a result of the consumption of stagnant water or grass which had been cut in an irrigated area, conditions that are common in the dry season in the semiarid region.

An antithrombin-dependent sulfated polysaccharide isolated from the green alga Caulerpa cupressoides has in vivo anti- and prothrombotic effects / Um polissacarídeo sulfatado dependente de antitrombina isolado da alga verde Caulerpa cupressoides possui efeitos anti- e pró-trombótico 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.

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.

An antithrombin-dependent sulfated polysaccharide isolated from the green alga Caulerpa cupressoides has in vivo anti- and prothrombotic effects

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.

An antithrombin-dependent sulfated polysaccharide isolated from the green alga Caulerpa cupressoides has in vivo anti- and prothrombotic effects

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.