RESUMO
BACKGROUND: Snakebite envenomation (SBE) causes diverse toxic effects in humans, including disability and death. Current antivenom therapies effectively prevent death but fail to block local tissue damage, leading to an increase in the severity of envenomation; thus, seeking alternative treatments is crucial. METHODS: This study analyzed the potential of two fucoidan sulfated polysaccharides extracted from brown seaweeds Fucus vesiculosus (FVF) and Undaria pinnatifida (UPF) against the fibrinogen or plasma coagulation, proteolytic, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom. The toxicity of FVF and UPF was assessed by the hemocompatibility test. RESULTS: FVF and UPF did not lyse human red blood cells. FVF and UPF inhibited the proteolytic activity of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom by approximately 25%, 50%, and 75%, respectively, while all venoms led to a 20% inhibition of PLA2 activity. UPF and FVF delayed plasma coagulation caused by the venoms of B. jararaca and B. neuwiedi but did not affect the activity of B. jararacussu venom. FVF and UPF blocked the coagulation of fibrinogen induced by all these Bothropic venoms. CONCLUSION: FVF and UPF may be of importance as adjuvants for SBE caused by species of Bothrops, which are the most medically relevant snakebite incidents in South America, especially Brazil.
Assuntos
Coagulação Sanguínea , Venenos de Crotalídeos , Fucus , Fosfolipases A2 , Polissacarídeos , Undaria , Animais , Antivenenos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Bothrops , Bothrops jararaca , Venenos de Crotalídeos/toxicidade , Venenos de Crotalídeos/enzimologia , Algas Comestíveis/química , Fucus/química , Fosfolipases A2/metabolismo , Polissacarídeos/farmacologia , Polissacarídeos/isolamento & purificação , Proteólise/efeitos dos fármacos , Alga Marinha/química , Undaria/química , Serpentes PeçonhentasRESUMO
The present study had the objective to investigate the equilibrium, kinetics, thermodynamic viability and system optimization of methylene blue (MB) and eriochrome black T (ET) biosorption onto Fucus vesiculosus (F. vesiculosus). A comprehensive bioadsorbent characterization was carried out. The infrared spectra suggested a physical biosorption mechanism that was later proven by the enthalpy change and the isotherms models. Furthermore, the process was best described by Langmuir and Temkin isotherm models, indicating the monolayer formation and the linear reduction of the heat of biosorption with the coverage degree. F. vesiculosus presented a maximum biosorption capacity of 698.477â mg·g-1 for MB, and 24.306â mg·g-1 for ET. Regarding kinetics, the pseudo-second-order kinetic model was the best fitted model. In addition, the film diffusion was confirmed as the process limiting step. The model's optimization was achieved in order to maximize the removal efficiency, corresponding to 99.28% for MB and 99.44% for ET.
Assuntos
Fucus , Alga Marinha , Poluentes Químicos da Água , Adsorção , Compostos Azo , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno , Termodinâmica , Poluentes Químicos da Água/análiseRESUMO
Due to the anthropic activities, several heavy metal ions are introduced into the environment, impacting ecosystems and local activities. In this context, the biosorption process using algae represents an alternative form for these compounds remediation due to the advantages derived from the biosorbent and process efficiency. Thus, the present study evaluated Cadmium (Cd(II)), Nickel (Ni(II)) and Lead (Pb(II)) remediation from aqueous media in mono- and multi-component systems. The biosorbent was characterized in terms of its morphology and composition and parameters involving equilibrium, kinetics, and thermodynamics were investigated. Lastly, the sample was considered in a real surface water sample remediation impacted by a mining dam rupture. Except for Freundlich, all isotherm models tested satisfactorily adjusted to the experimental data for a mono-component system. The maximum biosorption capacities (qm) were 143.2⯱â¯7.5, 70.1⯱â¯1.9, 516.3⯱â¯12.5â¯mgâ¯g-1 for Cd(II), Ni(II) and Pb(II) ions, respectively. When binary systems were considered, an antagonism effect was observed. The biosorption of Cd(II) was drastically affected by the presence of Ni(II), while Pb(II) biosorption in general was less affected by other metals presence. As observed for the binary system, the worst effect in the ternary system was observed for Cd(II) biosorption, being significantly affected by Ni(II) and Pb(II) presence. Overall, the biosorption order in mono- and multi-component systems was found to be Pb(II)â¯â«â¯Cd(II)â¯>â¯Ni(II). The affinity for the metals ions was also observed by Elovich's desorption constant, in which aPb(II)âªaCd(II)aCd(II), achieving an equilibrium passed 49â¯min. From the stages involved in biosorption process, film diffusion presented the greatest contribution as control-stage obtaining a lower diffusion coefficient in all cases. The process was spontaneous in all temperature range evaluated, considered exothermic for all metal ions evaluated. Iron, manganese and nickel concentrations in real surface water samples were higher than the allowed by the Brazilian National Environment Council (CONAMA). Comparing the hazard index values before and after the biosorption process, a reduction superior to 8â¯×â¯was observed (HIbefore: 3.36, HIafter: 0.40), in which there was no non-carcinogenic risk imposed to the surrounding population after the treatment applied.
Assuntos
Fucus , Alga Marinha , Adsorção , Biomassa , Brasil , Cádmio , Ecossistema , Concentração de Íons de Hidrogênio , Cinética , Chumbo , TermodinâmicaRESUMO
Fucus vesiculosus is a brown seaweed used in the treatment of obesity. This seaweed synthesizes various bioactive molecules, one of them being a sulfated polysaccharide known as fucoidan (FF). This polymer can easily be found commercially, and has antiadipogenic and lipolytic activity. Using differential precipitation with acetone, we obtained four fucoidan-rich fractions (F0.5/F0.9/F1.1/F2.0) from FF. These fractions contain different proportions of fucose:glucuronic acid:galactose:xylose:sulfate, and also showed different electrophoretic mobility and antioxidant activity. Using 3T3-L1 adipocytes, we found that all samples had lipolytic action, especially F2.0, which tripled the amount of glycerol in the cellular medium. Moreover, we observed that FF, F1.0, and F2.0 have antiadipogenic activity, as they inhibited the oil red staining by cells at 40%, 40%, and 50%, respectively. In addition, they decreased the expression of key proteins of adipogenic differentiation (C/EBPα, C/EBPß, and PPARγ). However, F0.5 and F0.9 stimulated the oil red staining at 80% and increased the expression of these proteins. Therefore, these fucoidan fractions have an adipogenic effect. Overall, the data show that F2.0 has great potential to be used as an agent against obesity as it displays better antioxidant, lipolytic and antiadipogenic activities than the other fucoidan fractions that we tested.
Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Fucus/química , Polissacarídeos/farmacologia , Células 3T3 , Animais , Antioxidantes/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Fucose/farmacologia , Galactose/farmacologia , Camundongos , PPAR gama/metabolismo , Alga Marinha/química , Sulfatos/farmacologia , Xilose/farmacologiaRESUMO
Fucoidan, a sulfated polysaccharide from the brown algae Fucus vesiculosus, has diverse biological properties, including anti-inflammatory, anticoagulant and antithrombotic activity. This study analyzed the therapeutic activity of total fucoidan (TF) from F. vesiculosus and that of purified fractions (F1 and F2) on zymosan-induced arthritis. Arthritis was induced by injecting zymosan into the knee joint. Thus, three fucoidan fractions were obtained by acetone fractionation. Due to the yield obtained from F3, we used only fucoidans F1 and F2 in the induced inflammation tests. Chemical analyses and electrophoretic characterization of these fractions demonstrated that they contain polysaccharides, sulfate ester and very low protein levels. The fucoidans obtained from TF showed only an electrophoretic band in agarose gel with much lower polydispersion. The F2 fraction showed a migration between fucoidans F1 and F3. We administered TF (15, 30, 50 mg/kg I. P.), F1 or F2 (10, 25 and 50 mg/kg I. P.), diclofenac sodium (10 mg/kg I. P.), lumiracoxib (5 mg/kg O. A.) or L-NAME (30 mg/kg I. P.), 1 hour after induction of articular inflammation. We analyzed cell influx and nitrite levels in addition to performing histopathological analysis. TF (total fucoidan) at 15, 30, 50 mg/kg I. P. and its fractions (F1 and F2 at concentrations of 25 and 50 mg/kg I. P.) significantly reduced cellular influx and nitric oxide concentration. Moreover, the articular inflammation in zymosan-induced arthritis caused a progressive loss in glycosaminoglycan content. This loss decreased when TF (30 mg/kg) was administered. These data suggest that fucoidan exerts anti-inflammatory action in a zymosan-induced model of acute inflammation in rats. Taken together with the fact that these natural compounds have minimal toxicity, this may have important therapeutic implications.
Assuntos
Anti-Inflamatórios/uso terapêutico , Artrite Experimental/tratamento farmacológico , Fucus/química , Leucócitos/metabolismo , Extratos Vegetais/uso terapêutico , Polissacarídeos/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Artrite Experimental/induzido quimicamente , Artrite Experimental/imunologia , Glicosaminoglicanos/metabolismo , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/metabolismo , Articulação do Joelho/metabolismo , Masculino , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Ratos , Ratos Wistar , Sulfatos , ZimosanRESUMO
Polysaccharides extracted from brown marine algae represent a source of marine compounds with potential applications in medicine. Heparin-like compounds, fucoidans, have been proposed as alternatives to the anticoagulant heparin, which is prepared from mucous membrane of mammals. In this study, the activity of anticoagulant in activated partial thromboplastin time (APTT) and prothrombin time (PT) tests was assessed in the fucoidan (TF), from seaweed Fucus vesiculosus, partially desulfated fucoidans (PDF), desulfated fucoidans (DF) and purified fractions F1, F2 and F3 in acetone. Studies were also conducted to assess these polysaccharides for platelet aggregation and hemorrhagic activity. The APTT test showed high activity at 5 microg (> or = 240s) for TF, F1 and F2 (P<0.001). PT test showed high anticoagulant activity at 50 microg (> or = 120s) for F1 (P<0.001). Fraction F3, with low MW (15.2 kDa) and sulfate content (26.1%), had little effect in these two in vitro tests (P<0.001). These compounds demonstrated a two-phase response to platelet aggregation at 50 microg/mL. However, at a concentration of 0.1 mg/mL, a hypoaggregate profile was observed for all fractions tested (P<0.001). The analysis showed that fucoidans irreversibly induced platelet aggregation in high concentration. These polymers have low hemorrhagic effect when compared to heparin.
Assuntos
Anticoagulantes/farmacologia , Fucus/química , Heparinoides/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Polissacarídeos/farmacologia , Animais , Anticoagulantes/efeitos adversos , Anticoagulantes/química , Inibidores do Fator Xa , Hemorragia/induzido quimicamente , Heparinoides/efeitos adversos , Heparinoides/química , Humanos , Técnicas In Vitro , Tempo de Tromboplastina Parcial , Polissacarídeos/efeitos adversos , Polissacarídeos/química , Tempo de Protrombina , Ratos , Ratos Wistar , Alga Marinha/química , Trombina/antagonistas & inibidoresRESUMO
The present study shows the cytotoxic effect of three different classes of algal polysaccharides on HL60 cells. Three galactofucans, fucoidan, and glucan were the polysaccharides utilized in this analysis. The parameters used for evaluating cell viability were [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) reduction, protein content, and phosphatase activity. We demonstrated stimulation of phosphatase activity, MTT reduction, and protein content in relation to three types of galactofucans (1, 2, and 3) with different molecular weights (1600, 1200, and 360 kD). However, when HL60 cells were treated with galactofucan type 3, the total protein remained unchanged. Under the same experimental conditions, an expressed increase in the phosphatase activity was detected when galactofucan 3 was utilized. In relation to the mitochondrial function, the stimulation was higher in cells treated with galactofucan type 1. Fucoidan did not have a significant effect on MTT reduction, but protein content was decreased (IC50 around 30 microg/ml). Glucan also activated all the parameters that were analyzed, and this effect was more expressed in the phosphatase activity and in the protein content. This study provides new insights into the cytotoxic action of polysaccharides on HL60 cells and suggests for the first time the possible involvement of phosphatases in this process.
Assuntos
Citotoxinas/farmacologia , Fucus/química , Galactanos/farmacologia , Glucanos/farmacologia , Monoéster Fosfórico Hidrolases/metabolismo , Polissacarídeos Bacterianos/farmacologia , Polissacarídeos/farmacologia , Alga Marinha/química , Citotoxinas/química , Galactanos/química , Glucanos/química , Células HL-60 , Humanos , Polissacarídeos/química , Polissacarídeos Bacterianos/químicaRESUMO
Los fitoflagelados son un grupo heterogéneo de flagelados autotróficos, heterotróficos y mixotróficos, con importancia ecológica para los niveles tróficos en diferentes ecosistemas. Los fitoflagelados en costas del Pacífico mexicano (y en Latinoamérica en términos generales) son virtualmente desconocidos, sólo se tienen pocos registros. El estudio de los fitoflagelados requiere de métodos complicados de recolección y análisis. Esta es, probablemente, la causa de la escasez de conocimiento de este grupo en áreas tropicales y subtropicales. Material recientemente recolectado a lo largo del Pacífico mexicano sirvió para el estudio de fitoflagelados marinos, incluyendo algunos tóxicos y potencialmente tóxicos. Se usaron muestras de plancton filtradas por gravedad y con bomba de vacío utilizando diferentes métodos de fijación y análisis. Se registran aquellas especies presentes o con posibilidad de estarlo que son potencialmente nocivas para el ecosistema marino pertenecientes a los Phyla Euglenophyta, Heterokontophyta y Haptophyta. Estas especies están distribuidas en el plancton, en aguas oceánicas y costeras
The phytoflagellates are a heterogeneous group of autotrophic, heterotrophic and mixothrophic flagellates of trophic importance in several ecosystems. As in the rest of Latin America, the phytoflagellates that occur in the Mexican Pacific coasts are virtually unknown except for a few records. Their study require complicated collection and analysis methods, a probable cause for the scarce knowledge of this group in tropical and subtropical areas. Material recently collected from various localities along the Mexican Pacific coasts was used to study phytoflagellates, including toxic and potentially toxic species. Plankton samples were treated by gravity and pump filtration, using different methods for fixation and analysis. The phyla Euglenophyta, Heterokontophyta and Haptophyta were found. They occur as plankton in oceanic and shallow coastal waters
Assuntos
Animais , Eucariotos , Fitoplâncton/química , Água do Mar/análise , Eucariotos , Euglênidos/classificação , Euglênidos/patogenicidade , Euglênidos/ultraestrutura , Fucus/classificação , Fucus/patogenicidade , Fucus/ultraestrutura , México , Ochromonas/classificação , Ochromonas/patogenicidade , Ochromonas/ultraestrutura , Técnicas de Cultura de Órgãos/métodos , Oceano PacíficoRESUMO
The phytoflagellates are a heterogeneous group of autotrophic, heterotrophic and mixothrophic flagellates of trophic importance in several ecosystems. As in the rest of Latin America, the phytoflagellates that occur in the Mexican Pacific coasts are virtually unknown except for a few records. Their study require complicated collection and analysis methods, a probable cause for the scarce knowledge of this group in tropical and subtropical areas. Material recently collected from various localities along the Mexican Pacific coasts was used to study phytoflagellates, including toxic and potentially toxic species. Plankton samples were treated by gravity and pump filtration, using different methods for fixation and analysis. The phyla Euglenophyta, Heterokontophyta and Haptophyta were found. They occur as plankton in oceanic and shallow coastal waters.