Fatty acid profile in vertical strata of elephant grass subjected to intermittent stocking

ABSTRACT The milk and meat from animals with a pasture-based diet have higher proportions of CLA and C18:3 and lower omega-6:omega-3 ratios than products from animals with diets based on corn silage and concentrate. However, most of the published studies have evaluated fatty acid profiles in temperate climate grasses and the literature with tropical grasses is scarce. Thus, the aim of this study was to evaluate the morphological and fatty acid compositions in the vertical strata of elephant grass (Pennisetum purpureum Schum.) swards subjected to grazing heights (90 or 120 cm pre-grazing heights) and levels of defoliation (50% or 70% removal of the initial pre-grazing height). There were no interactions among pre-grazing height, the level of defoliation and grazing stratum. However, higher proportion of C18:3 (58% and 63%) was found in the 90-cm swards and in the half upper stratum. A higher proportion of C18:3 was associated with a higher leaf proportion and crude protein content. Thus, the upper stratum of sward or a grazing management scheme (e.g. first-last stocking) resulting in a higher proportion of leaves and crude protein both provide higher proportions of C18:3 to animals grazing in elephant grass swards.

Fatty acid profile in vertical strata of elephant grass subjected to intermittent stocking.

The milk and meat from animals with a pasture-based diet have higher proportions of CLA and C18:3 and lower omega-6:omega-3 ratios than products from animals with diets based on corn silage and concentrate. However, most of the published studies have evaluated fatty acid profiles in temperate climate grasses and the literature with tropical grasses is scarce. Thus, the aim of this study was to evaluate the morphological and fatty acid compositions in the vertical strata of elephant grass (Pennisetum purpureum Schum.) swards subjected to grazing heights (90 or 120 cm pre-grazing heights) and levels of defoliation (50% or 70% removal of the initial pre-grazing height). There were no interactions among pre-grazing height, the level of defoliation and grazing stratum. However, higher proportion of C18:3 (58% and 63%) was found in the 90-cm swards and in the half upper stratum. A higher proportion of C18:3 was associated with a higher leaf proportion and crude protein content. Thus, the upper stratum of sward or a grazing management scheme (e.g. first-last stocking) resulting in a higher proportion of leaves and crude protein both provide higher proportions of C18:3 to animals grazing in elephant grass swards.

Ecological risk analysis of pesticides used on irrigated rice crops in southern Brazil.

Based on studies conducted in the past decade in the southern region of Brazil to determine residue levels of the pesticides normally used on irrigated rice crops, changes can be observed in relation to the presence of pesticides in the waters of the main river basins in Santa Catarina State. In previous harvests, the presence of residues of 7 pesticides was determined, with the herbicide bentazon and the insecticide carbofuran being the products showing highest frequency. Following toxicological tests conducted with 8 different test organisms, deterministic and probabilistic risk analysis was performed to assess the situation of the river basins in areas used for the production of irrigated rice. Of the species tested, the herbicide bentazon showed greatest toxicity toward plants, but did not present an ecological risk because in the worst-case scenario the highest concentration of this pesticide in the environment is 37 times lower than the lowest EC50/LC50 value obtained in the tests. The insecticide carbofuran, which had the highest toxicity toward the organisms used in the tests, presented an ecological risk in the deterministic analysis, but without any associated probability. The results highlight the need for increased efforts in training farmers in crop management practices and for the continual monitor of water bodies for the presence of pesticide residues.

Diet-induced obesity impairs AKT signalling in the retina and causes retinal degeneration.

Retinopathy, a common complication of diabetes, is characterized by an unbalanced production of nitric oxide (NO), a process regulated by nitric oxide synthase (NOS). We hypothesized that retinopathy might stem from changes in the insulin receptor substrate (IRS)/PI3K/AKT pathway and/or expression of NOS isoforms. Thus, we analysed the morphology and apoptosis index in retinas of obese rats in whom insulin resistance had been induced by a high-fat diet (HFD). Immunoblotting analysis revealed that the retinal tissue of HFD rats had lower levels of AKT(1) , eNOS and nNOS protein than those of samples taken from control animals. Furthermore, immunohistochemical analyses indicated higher levels of iNOS and 4-hydroxynonenal and a larger number of apoptotic nuclei in HFD rats. Finally, both the inner and outer retinal layers of HFD rats were thinner than those in their control counterparts. When considered alongside previous results, these patterns suggest two major ways in which HFD might impact animals: direct activity of ingested fatty acids and/or via insulin-resistance-induced changes in intracellular pathways. We discuss these possibilities in further detail and advocate the use of this animal model for further understanding relationships between retinopathy, metabolic syndrome and type 2 diabetes.

Ripe fruits of Bromelia antiacantha: investigations on the chemical and bioactivity profile / Quimica e atividade in vitro da banana-do-mato (Bromelia antiacantha Bertol., Bromeliaceae)

Bromelia antiacantha (known as wild banana) is traditionally used to treat coughs, as an emollient and antitussive, and to treat mouth and skin ulcers. To investigate the radical scavenger properties, DPPH and phosphomolybdenium were used, with low antioxidant activity being observed for both (below 5 mg/ml of extract presented no activity for both techniques). An HPLC fingerprint of phenolic compounds was developed and total phenolics through Folin-Ciocalteau method was an average of 500 µg/g of fresh fruits. Any cytotoxicity was observed on L929 fibroblasts cells for aqueous, methanol and lipid extracts between 500 and 0.01 µg/ ml. The wild banana extract (1000 µg/mL) shown a lower genotoxicity when compared to the negative and positive (MMS) controls. Abundant calcium oxalate crystals and sucrose were found and characterized through NMR and X-ray diffraction respectively. Its centesimal composition indicated abundant carbohydrates (45 percent) and lipids (18 percent). The carbohydrate analysis showed acidic monosaccharides, and the lipid analysis shown palmitic and linoleic acids in similar quantities (30 percent each) and oleic acid 20 percent, among others, through GC-FID. The viscosity of the water-soluble polysaccharide sub-fraction (5 g/L) was similar to that of water.

O chá dos frutos maduros de Bromelia antiacantha (banana-de-bugre; banana-do-mato) é usado tradicionalmente para tratar desordens respiratórias, como antitussígeno e também para tratar ulceras de pele e boca. Neste trabalho pesquisou-se o potencial de captação de radicais livres do extrato aquoso e extrato metanólico através da reação de redução do DPPH e do fosfomolibdenio, sendo encontrada baixa atividade nos dois modelos (abaixo de 5 mg/ml nenhuma atividade foi detectada em ambos extratos). Os compostos fenólicos totais foram determinados através de Folin-Ciocalteau, sendo encontrados 500 µg/g de fruto maduro fresco, e foi desenvolvido fingerprint dos compostos fenólicos através de CLAE-DAD. Nenhuma citotoxicidade foi observada em fibroblastos L929 para extratos aquoso, metanólico e lipídico entre 500 e 0,01 µg/ml, assim como baixa genotoxicidade (1000 µg/mL) quando comparados aos controles negativo e positivo (MMS). Abundantes cristais de oxalato de cálcio e de sacarose foram observados e caracterizados por RMN e difração de Raios-X respectivamente, e a composição centesimal do fruto indicou abundantes carboidratos (45 por cento) e lipídeos (18 por cento). A analise de carboidratos encontrou componentes monosacarídicos ácidos e foram encontrados acido palmítico e linoléico em quantidades similares (30 por cento cada) e 20 por cento de acido oléico, entre outros ácidos graxos através de CG-DIC. A viscosidade da sub-fração polissacarídica solúvel em água (5 g/L) foi semelhante a da água.

Characterization and potential uses of Copaifera langsdorfii seeds and seed oil.

Copaifera langsdorfii (Desf.) Kuntze (copaiba) seeds are abundantly produced and have not yet been characterized. The seed oil presents a characteristic odor of coumarin (250.1+/-6.57 mg/g determined through LC). The fatty acid composition of the oil was determined through CG/FID, being 45.3% linoleic acid, 32.3% monounsaturated, and 22.4% saturated fat. For the lipid-free seeds, the total carbohydrate, protein and moisture were 75.4%, 6.8% and 14.8%, respectively. The C. langsdorfii xyloglucan had an intrinsic viscosity of 804 mL/g, and the average molar mass (Mw) was 7.82 x 10(5)g/mol and Rg of 65 nm. The degree of polydispersion was 1.7, indicating the polydisperse family of polysaccharides. Its homogeneity, low degree of polymer contaminants and high intrinsic viscosity and molecular mass, represent good potential as a thickening agent. The presence of coumarin and xyloglucan as major components of C. langsdorfii seeds denotes its potential for use in the cosmetic or pharmaceutical industries.

Risk analysis of herbicide quinclorac residues in irrigated rice areas, Santa Catarina, Brazil.

Deterministic and probabilistic risk analyses were carried out for seven hydrographic basins in the State of Santa Catarina (Brazil), where irrigated rice is cultivated. Monitoring studies conducted in 1998/1999 and 1999/2000 had found that the herbicide quinclorac was the most frequently detected agrochemical residue, occurring in five of the seven hydrographic basins. In order to assess the ecological risk posed by quinclorac, median lethal concentration (LC(50)) and median effective concentration (EC(50)) data were obtained for quinclorac in toxicity tests with organisms routinely used in Brazil for this purpose. Experiments were carried out on microcosms associated with the irrigated rice crop to evaluate the effects of the herbicide on the natural plankton community. The deterministic analyses showed that the risk presented by the herbicide residues to the phytoplankton require mitigating action, while the probabilistic analysis revealed that the levels of risk for the aquatic community were acceptable. Field experiments showed that the recommended application concentration of the product directly affects phytoplankton and has an indirect, short-term effect on the zooplankton community.

Análise de óleos-resinas de copaíba: contribuição para o seu controle de qualidade / Copaiba oil-resin analysis: contribution to quality control

A óleo-resina de copaíba pode ser extraída de forma sustentável do tronco de várias espécies de Copaifera. Ela contém principalmente ácidos resinosos e substâncias voláteis, tendo ampla utilização medicinal. A padronização cromatográfica do óleo é a garantia da identidade desta matéria-prima complexa. Neste trabalho analisaram-se por CG três amostras de óleos de copaíba obtidas de Colombo/PR e doze amostras adquiridas no Estado do Amazonas. O óleo de copaiba foi fracionado por cromatografia em sílica gel impregnada com KOH e metilado e as frações obtidas foram avaliadas por CG. Numa segunda etapa, os óleos brutos metilados por meio de diazometano ou transesterificados com KOH/MeOH foram injetados diretamente em CG. Foram utilizados para comparação os ácidos diterpênicos hardwíckiico, copaiferólico e caurenóico além do sesquiterpeno 14-hidroxi-b-cariofileno (cariofilenol). A presença do ácido copaiferólico foi observada em 100 por cento e cariofilenol em 80 por cento das amostras. Os ácidos caurenóico e hardwíckiico ausentes nas amostras do Paraná, foram detectados em 8,3 por cento e 41,7 por cento respectivamente nas amostras do Amazonas. Os resultados obtidos indicam que podem ser analisados diretamente através de CG após metilação com diazometano, sem necessidade de fracionamento prévio. Adicionalmente, a determinação do índice de acidez para óleos de copaíba não demonstrou resultados inequívocos para as amostras analisadas.

Copaiba oil can be extracted from the trunk of some Copaifera species and contains mainly resinous acids and volatile substances, which have wide medicinal use. The chromatographic standardization of the oil characteristics is the guarantee of the identity of raw material. In this work, three copaiba oil samples from Colombo/PR, and twelve from Amazonas State were analyzed. The copaiba oil was fractionated in silica gel impregnated with KOH, esterified and the fractions were evaluated by TLC and GC. In a second stage, the crude oil was esterified with diazomethane or transesterified with KOH/MeOH and injected in GC. The diterpene acids used for comparison were hardwickiic, copaiferolic and caurenoic and the 14-hydroxy-b-caryophyllene (caryophyllenol). The presence of copaiferolic acid was observed in all analyzed samples and caryophyllenol in 80 percent of the samples. Hardwickiic and caurenoic acids were absent in the samples from Paraná State, and respectively detected in 8.3 percent and 41.7 percent, of the samples from Amazonas. The obtained results indicate that the oil can be directly analyzed through GC after methylation with diazomethane, without previous fractionation. Also, an acidity index method proposed for copaiba oil analysis did not show to be reliable for the analyzed samples.