RESUMO
Dextrans (α-d-glucans) extracted from Leuconostoc mesenteroides, with molecular weights (MW) of 10 (D10), 40 (D40) and 147 (D147) kDa, were evaluated as antioxidant, anticoagulant and immunomodulatory drugs for the first time. None presented anticoagulant activity. As for the antioxidant and immunomodulatory tests, a specific test showed an increase in the dextran activity that was proportional to the increase in molecular weight. In a different assay, however, activity decreased or showed no correlation to the MW. As an example, the reducing power assay showed that D147 was twice as potent as other dextrans. On the other hand, all three samples showed similar activity (50%) when it came to scavenging the OH radical, whereas only the D10 sample showed sharp activity (50%) when it came to scavenging the superoxide ion. D40 was the single dextran that presented with immunomodulatory features since it stimulated the proliferation (~50%) of murine macrophages (RAW 264.7) and decreased the release of nitric oxide (~40%) by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). These points toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use. However, future studies with the D40 and other similarly 40 kDa dextrans are underway to confirm this hypothesis.
Assuntos
Antioxidantes/química , Dextranos/química , Animais , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Dextranos/farmacologia , Leuconostoc mesenteroides/química , Peroxidação de Lipídeos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Peso Molecular , Óxido Nítrico/metabolismo , Células RAW 264.7RESUMO
Background: feed and light are the most important factors affecting the biological rhythms of fish. This work studies fish adaptation to those factors. Objetive: to determine the influence of feeding time and dietary starch and lipid levels on growth, body composition, and liver histology of hybridized Brazilian catfish. Methods: two isoenergetic diets were formulated to contain two levels of crude starch (CHO, %) and lipids (L, %): 5/11 CHO/L and 25/2.2 CHO/L. Sixty animals (260 ± 10 g) were randomly distributed into twelve tanks (100 L). Using self-feeders, two fish groups were fed a diet containing either 5% or 25% starch during the light period (ML), while other two groups were fed the same diets during the dark period (MD). The following parameters were measured: final weight, weight gain, specific growth rate, food intake, hepatosomatic index, and viscerasomatic index. The experiment was carried out in triplicate for 60 days. Results: growth parameters such as specific growth rate (SGR), final weight, and weight gain showed statistical differences between groups, with the best results for the group fed the 25% starch diet during ML. Significant differences between groups on body lipid content, energy, and dry weight were also recorded for those feed 25% starch in the MD. A significant effect was also observed on liver lipid and glycogen content, with values generally higher for ML with 5% starch. Fish fed 25% starch showed significantly lowest lipid and glycogen content during ML. Surprisingly, the opposite occurred regarding liver composition for fish fed in MD. Conclusions: we suggest diurnal feeding should be practiced for optimal performance of juvenile fish, however dark or light phases could be used, taking into consideration its relationship with carbohydrate levels.
Antecedentes: la alimentación y la luz son los factores más importantes que afectan los ritmos biológicos en peces. En este artículo se presenta un poco de conocimiento acerca de la plasticidad de los peces para la utilización del alimento. Objetivo: este estudio se realizó para determinar la influencia del horario de alimentación y los niveles de almidón y lípidos de la dieta en el crecimiento, la composición corporal y la histología hepática en el bagre híbrido. Métodos: fueron formuladas dos dietas isoenergéticas para contener dos niveles de almidón (CHO, %) y lípidos (L, %): 5/11 CHO/L y 25/2.2 CHO/L. Sesenta animales (260 ± 10 g) fueron distribuidos aleatoriamente en 12 tanques (100 L). Un grupo de peces fue alimentado con 5% de almidón en el periodo diurno (ML), y otro grupo fue alimentado en el periodo nocturno (MD). Se realizaron los mismos procedimientos para el grupo alimentado con 25% de almidón. Los siguientes parámetros fueron medidos: peso final, ganancia de peso, tasa de crecimiento especifico, ingestión alimentaria, índice hepatosomático y índice vicerosomático. El experimento se realizó por triplicado durante 60 días. Resultados: los parámetros de crecimiento como la tasa de crecimiento específico (SGR), peso final y ganancia de peso mostraron diferencias estadísticas entre los grupos, con mejores resultados en los grupos alimentados con 25% de almidón en ML. Se observaron diferencias significativas entre los grupos para el contenido de lípidos en el cuerpo, energía y materia seca, para los animales alimentados con 25% de almidón en MD. Hubo un efecto significativo sobre los lípidos hepático y glucógeno, con los valores generalmente más altos en ML para los peces alimentados con 5% de almidón. Sin embargo, los peces alimentados con 25% de almidón presentaron significativamente menor contenido de lípidos y glucógeno en la condición de ML. Sin embargo, ocurrió lo contrario con los peces alimentados en MD, para la composición del hígado. Conclusiones: la alimentación diurna se sugirió para un mejor rendimiento de los juveniles, sin embargo, la fase nocturna o de luz se podrían utilizar, teniendo en cuenta su relación con los niveles de carbohidratos.
Antecedentes: alimentos e luz são os fatores mais importantes que arrastam os ritmos biológicos em peixes. Neste trabalho, trazemos um pouco do conhecimento sobre a plasticidade dos peixes para a utilização dos alimentos. Objetivo: este estudo foi realizado para determinar a influencia do horário de alimentação e níveis de amido e lipídio dietético no crescimento, composição corporal e histologia hepática em um bagre hibrido. Métodos: duas dietas isoenergéticas foram formuladas para conter dois níveis de amido (CHO, %) e lipídeo (L, %): 5/11 CHO/L e 25/2.2 CHO/L. Sessenta animais (260 ± 10 g) foram distribuídos aleatoriamente em 12 tanques (100 L). Um grupo de peixes foi alimentado com 5% de amido no período diurno (ML), e outro grupo foi alimentado no período noturno (MD). Os mesmos procedimentos foram realizados para o grupo que de alimentava com 25% de amido. Os seguintes parâmetros foram medidos: peso final, ganho de peso, taxa de crescimento especifico, consumo, índice hepatossomático y índice vicerossomático. O experimento foi conduzido em triplicado por 60 dias. Resultados: os parâmetros de crescimento como SGR, peso final e ganho de peso mostraram diferença estatística entre os grupos, com melhores resultados nos grupos alimentados com 25% de amido em ML. Diferença significativa entre grupos para conteúdo de lipídio na carcaça, energia e material seca foram observados para os animais alimentados com 25% de amido em MD. Foi observado efeito significativo no lipídio hepático e glicogênio com valores em geral mais altos em ML para os peixes alimentados com 5% de amido. Entretanto, os peixes alimentados com 25% de amido mostraram significativamente baixo conteúdo de lipídio e glicogênio sobre a condição de MD. Surpreendentemente, o oposto correu com os peixes alimentados em MD, para a composição do fígado. Conclusões: a alimentação diurna foi sugerida para um melhor desempenho dos juvenis, no entanto, a fase noturna ou de luz poderiam ser usados , levando em consideração sua relação com os níveis de carboidratos.
RESUMO
The prophylactic and therapeutic arsenal against malaria is quite restricted and all the antimalarials currently in use have limitations. Thus, there is a need to investigate medicinal plants in the search for phytochemicals which can be developed into drugs. In our investigation, essential oils (EOs) were obtained from Vanillosmopsis arborea (Gardner) Baker, Lippia sidoides Cham. and Croton zehntneri Pax & K. Hoffm., aromatic plants abundant in northeastern Brazil, which are found in the caatinga region and are used in traditional medicine. The chemical composition of these EOs was characterized by GC-MS, and monoterpenes and sesquiterpenes were well represented. We assessed the in vitro activity of these EOs and also individual EO chemical components against the human malaria parasite Plasmodium falciparum (K1 strain) and the in vivo activity of EOs in mice infected with Plasmodium berghei. The acute toxicity of these oils was assessed in healthy mice and in vitro cytotoxicity was determined at different concentrations against HeLa cells and mice macrophages. The EO of V. Arborea was partially active only when using the subcutaneous route (inhibited from 33 up to 47 %). In relation to the EOs, L. sidoides and C. zehntneri were active only by the oral route (per gavage) and partially inhibited the growth of P. berghei from 43 up to 55 % and showed good activity against P. falciparum in vitro (IC (50) = 7.00, 10.50, and 15.20 µg/mL, respectively). Individual EO constituents α-bisabolol, estragole, and thymol also exhibited good activity against P. falciparum (IC (50) = 5.00, 30.70, and 4.50 µg/mL, respectively). This is the first study showing evidence for the antimalarial activity of these species from northeastern Brazil and the low toxicity of their EOs.
Assuntos
Antimaláricos/administração & dosagem , Asteraceae/química , Croton/química , Lippia/química , Malária Falciparum/tratamento farmacológico , Óleos Voláteis/administração & dosagem , Fitoterapia , Administração Oral , Derivados de Alilbenzenos , Animais , Anisóis/administração & dosagem , Brasil , Células HeLa/efeitos dos fármacos , Humanos , Infusões Subcutâneas , Camundongos , Sesquiterpenos Monocíclicos , Folhas de Planta/química , Preparações de Plantas/administração & dosagem , Caules de Planta/química , Plantas Medicinais/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos/administração & dosagem , Timol/administração & dosagemRESUMO
A sulfated polysaccharide (SPSG) was successfully isolated from seagrass Halodule wrightii Asch., Cymodoceaceae, and its antioxidant and anticoagulant activities were investigated. The data presented here showed that the SPSG is a 11 kDa sulfated heterogalactan with a sulfatation degree of 20.63 percent and it also contains glucose and xylose. SPSG antioxidant activities were evaluated using several in vitro assays and the anticoagulant activity was evaluated by aPTT and PT tests. These assays suggested that the SPSG possessed remarkable antioxidant properties in different in vitro assays and an outstanding anticoagulant activity 2.5-fold higher than that of heparin Clexane® in the aPTT test. This data represents the first reported on the sulfated polysaccharide biological activities from seagrass. These results indicate that SPSG can be considered in the future as a drug utilized in treating diseases from these systems.
RESUMO
Fucan is a term used to denominate a family of sulfated polysaccharides rich in L-fucose. The brown alga Spatoglossum schröederi, Dictyotaceae, synthesizes three heterofucans named A, B, and C. Fucan A is a non-anticoagulant heterofucan which possesses potent antithrombotic (in vivo) and antiproliferative (in vitro) activities. However, its toxicity in vivo has not been determined. The present study examined the acute and subchronic toxicity of the fucan A in Wistar rats after subcutaneous administration. After that, the animals were killed and examined. The results showed in the acute study that fucan A did not cause general adverse effects and mortality in the concentrations 0, 20, 100, 1000, and 2000 µg/g body weight per rat for seven days. Regarding the subchronic study, the data showed that the fucan A did not cause any change in hematological and biochemistry parameters, as well as in the morphology, and in the size of the rat's organs analyzed at a concentration of 20 µg/g body weight per rat during a 62-day period. In conclusion, this study indicates this heterofucan is a compound with potential pharmacological value that has no toxicity in vivo.
RESUMO
Fucan is a term used to denominate a family of sulfated L-fucose-rich polysaccharides. The brown alga Spatoglossum schröederi (Dictyotaceae) has three heterofucans namely fucan A, B and C. The 21 kDa fucan A is composed of a core of a beta (1-3) glucuronic acid-containing oligosaccharide of 4.5 kDa with branches at C4 of the fucose chains alpha (1-3) linked. The fucose is mostly substituted at C4 with a sulfate group and at C2 with chains of beta (1-4) xylose. This fucan has neither anticoagulant (from from 0.1 to 100 microg) nor hemorrhagic activities (from 50 to 800 microg/mL). The antithrombotic test in vivo showed that fucan A has no activity in any of the concentrations (from 0.2 to 20 microg/g/day) tested 1 h after polysaccharide administration. However, when fucan A was injected endovenously 24 h before the ligature of the venae cavae, we observed a dose-dependent effect, reaching saturation at around 20 microg/g of rat weight. In addition, this effect is also time-dependent, reaching saturation around 16 h after fucan administration. In addition, regardless of the administration route, fucan A displayed antithrombotic activity. The exception was the oral pathway. Of particular importance was the finding that fucan A stimulates the synthesis of an antithrombotic heparan sulfate from endothelial cells like heparin. The hypothesis has been raised that the in vivo antithrombotic activity of fucan A is related to the increased production of this heparan. Taken together with the fact that the compound is practically devoid of anticoagulant and hemorrhagic activity, the data suggest that it may be an ideal antithrombotic agent in vivo.