RESUMEN
Nitric oxide (NO) and prostaglandin (PG)E2, known inflammatory mediators, are critically involved in the pathogenesis of a large number of human inflammatory diseases. Therefore, a search of inducible nitric oxide synthases (iNOS) and cyclooxygenase 2 (COX-2) selective inhibitors is a useful strategy to find functional substances to alleviate inflammatory disease. In our search for anti-inflammatory ingredients, we found that extracts of Ulva fasciata (UFE) and Desmarestia viridis (DVE) inhibit the generation of NO and PGE2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. U. fasciata and D. viridis were extracted with 80% ethanol and then partitioned successively with ethyl acetate. The ethyl acetate fractions are effective dose-dependent inhibitors of LPS-induced NO and PGE2 synthesis in RAW 264.7 cells. To test the inhibitory effects of UFE and DVE on pro-inflammatory cytokines, we performed ELISA assays for tumor necrosis factor (TNF)-α, IL (interleukin)-1β, and IL(interleukin)-6 in LPS-stimulated RAW 264.7 macrophage cells. In these assays, the UFE and DVE showed a dose-dependent decrease in the production of TNF-α, IL-1β, and IL-6. As a preliminary study of the anti-inflammatory mechanism, we determined, using the Western blot analysis, whether or not UFE and DVE inhibit the degradation of I-kappa-B-alpha (IκB-α). Our results indicate that UFE and DVE indeed prevent the degradation of IκB-α, in a dose-dependent manner. Based on these results, we suggest that extracts of U. fasciata and D. viridis be considered candidates for anti-inflammatory agents for human use.
RESUMEN
O presente trabalho teve por objetivo avaliar a duração da resistência induzida, a eficiência do número e intervalo de aplicações de ulvana, bem como a influência de diferentes concentrações de inóculo no controle e na severidade da antracnose do feijão. Para tanto, foram realizados três experimentos independentes. Plantas de feijão (P. vulgaris, cv. Uirapuru) foram cultivadas em condições de casa-de-vegetação e, no primeiro experimento, foram pulverizadas com ulvana em uma única aplicação aos: nove dias antes da inoculação (dai) V3(i); seis dai V3(m); três dai V3(f); ou duas aplicações consecutivas realizadas aos nove e seis dai V3(i)/(m); nove e três dai V3(i)/(f) ou seis e três dai V3(m)/(f) e inoculadas em um mesmo momento. No segundo e terceiro experimentos, plantas de feijão foram tratadas duas vezes (seis e três dai) e inoculadas em diferentes momentos ou com diferentes concentrações de inóculo, respectivamente. A pulverização de ulvana reduziu a severidade da antracnose em cerca de 50%. Duas aplicações de ulvana foram mais eficientes em induzir respostas de defesa em feijão contra a antracnose que somente uma. A maior redução (96%) da doença ocorreu com pulverizações sucessivas em V3(m)/(f). O efeito de duas aplicações do polissacarídeo persistiu até nove dias após o tratamento. A redução na severidade da antracnose foi maior quando foram utilizadas concentrações intermediárias de inóculo (105 e 106 conídios por mL).
The present work aimed to evaluate the persistence of the induced resistance, the efficiency of the number and the interval of ulvan applications and the influence of different inoculum concentrations in the control of bean anthracnose. Three independent experiments were carried out. Bean plants (P. vulgaris, cv. Uirapuru) were cultivated under green house conditions and, in the first experiment, they were treated with ulvan once at nine days before inoculation (dbi) V3(i); six dbi V3(m) or three dbi V3(f) or they were treated twice at nine and six dbi V3(i)/(m); nine and three V3(i)/(f) or six and three (dbi) V3(m)/(f), the they were inoculated at the same time. In the second and third experiments, bean plants were treated twice (six and three dbi) then inoculated in different moments or with different inoculums concentrations, respectively. The application of ulvan reduced the anthracnose severity by 50%. Two ulvan applications were more efficient in inducing defense responses in bean plants than a single application. The highest disease reduction (96%) was achieved by spraying ulvan twice at V3(m)/(f). The effect of two applications persists until nine days after the treatment. The reduction on the anthracnose severity was higher when intermediate (105 e 106 conidia per mL) inoculum concentrations were used.
Asunto(s)
Antifúngicos , Colletotrichum , PhaseolusRESUMEN
Objective To evaluate the In vitro antimicrobial and hemolytic activity of marine macroalgae Ulva fasciata (U. fasciata) collected from Mandapam coastal waters, and to identify certain seaweed extracts that can act as an alternative of commonly used antibiotics. Methods Seaweeds U. fasciata was collected from Gulf of Mannar, Southeast Coastal Region, Mandapam, Tamil Nadu and was screened for antimicrobial and hemolytic activity. Methanol, butanol and aqueous extracts were tested against selected fish pathogens, Aeromonas hydrophila, Pseudomonas fluorescens, Proteus sp. Vibrio alginolyticus (V. alginolyticus) and Enterobacter sp. and fungal pathogens Rhizopus sp., Aspergillus flavus, Aspergillus sp., Aspergillus niger and Candida sp. The extract was subjected to TLC to determine the presences of peptides and amide groups. And the hemolytic activity was assayed. Results Maximum of 16 mm inhibition zone was observed against V. alginolyticus and the minimum 12 mm against Enterobacter sp., respectively. U. fasciata showed poor activity against the fungal pathogens. The present results showed the use of seaweeds as an antimicrobial agents for pharmacology or as a health-promoting food for aquaculture. Conclusions The screening result confirms that these seaweeds can be further studied and used as possible source of antimicrobial compounds.
RESUMEN
This work aims to assess the potential of the green seaweed Ulva fasciata Delile as an alternative source of dietary fibre (DF). Total DF content was determined, some of its physico-chemical properties described and the physiological effects of U. fasciata meal on rats fed a hypercholesterolemic diet were investigated. U. fasciata may be considered a potential alternative source of DF with a total content of about 400 g.kg-1 (dry basis) and interesting physico-chemical properties: water retention capacity of 8.74 g/water.g-1 dry sample (seaweed meal) and 0.90 (seaweed carbohydrate extract), lipid adsorption capacity of 4.52 g/oil.g-1 dry sample (seaweed meal) and 5.70 (seaweed carbohydrate extract), intrinsic viscosity of 2.4 dl.g-1 (seaweed carbohydrate extract) and cation exchange capacity of 3.51 Eq.kg-1 (seaweed carbohydrate extract). The diet containing seaweed meal was able to keep rats' total cholesterol (TC) down without causing any undesirable increase in LDL-C fraction. No evidence of toxic and/or antinutritional components in the seaweed meal was detected. Rats showed a fecal volume much greater (13 g) than that fed on cellulose diet ( 7 g) (p < 0.05). These properties confer on the seaweed the potential to be used in food technology for the acquisition of low-calorie food and might be important in body weight control, reduction of blood TC and LDL-C as well as in prevention of gastrointestinal diseases.
Este trabalho objetivou avaliar o potencial da alga marinha verde Ulva fasciata Delile como fonte alternativa de fibra alimentar. Foram realizadas a determinação do teor de fibra alimentar total e a descrição de algumas propriedades físico-químicas, e os efeitos fisiológicos da farinha da alga seca sobre ratos alimentados com dieta hipercolesterolemizante foram investigados. Esta alga pode ser considerada uma fonte alternativa potencial de fibra com cerca de 400 g.kg-1 (base seca) e propriedades físico-químicas interessantes: uma capacidade de retenção de água de 8,74 g/água.g-1 de amostra seca (farinha de alga) e 0,90 (extrato de carboidratos), uma capacidade de adsorção de lipídeos de 4,52 g/óleo.g-1 de amostra seca (farinha de alga) e 5,70 (extrato de carboidratos), uma viscosidade intrínseca de 2,4 dl.g-1 (extrato de carboidrato da alga) e capacidade de troca iônica de 3,51 Eq.kg-1 (extrato de carboidrato). A dieta contendo farinha de alga foi capaz de manter baixos os níveis de colesterol total de ratos sem causar aumento indesejável na fração LDL-C. Nenhuma evidência de componentes tóxicos e/ou antinutricionais na farinha de alga foi encontrada. Os ratos mostraram um volume fecal maior (13 g) do que aqueles alimentados com dieta contendo celulose como fonte de fibra (7 g) (p < 0,05). Essas propriedades conferem a alga o potencial de ser utilizada na tecnologia de alimentos para a aquisição de alimentos de baixas calorias, podendo ser importante para o controle do peso corporal, redução do colesterol sanguíneo total e da fração LDL-C, como também na prevenção de doenças gastrintestinais.