Water extracts of cabbage and kale inhibit ex vivo H2O2-induced DNA damage but not rat hepatocarcinogenesis

The chemopreventive potential of water extracts of the Brassica vegetables cabbage and kale was evaluated by administering their aqueous extracts in drinking water ad libitum to Wistar rats submitted to Ito’s hepatocarcinogenesis model (CB group and K group, respectively - 14 rats per group). Animals submitted to this same model and treated with water were used as controls (W group - 15 rats). Treatment with the vegetable extracts did not inhibit (P > 0.05) placental glutathione S-transferase-positive preneoplastic lesions (PNL). The number of apoptotic bodies did not differ (P > 0.05) among the experimental groups. Ex vivo hydrogen peroxide treatment of rat livers resulted in lower (P < 0.05) DNA strand breakage in cabbage- (107.6 ± 7.8 µm) and kale- (110.8 ± 10.0 µm) treated animals compared with control (120.9 ± 12.7 µm), as evaluated by the single cell gel (comet) assay. Treatment with cabbage (2 ± 0.3 µg/g) or kale (4 ± 0.2 µg/g) resulted in increased (P < 0.05) hepatic lutein concentration compared with control (0.5 ± 0.07 µg/g). Despite the absence of inhibitory effects of cabbage and kale aqueous extracts on PNL, these Brassica vegetables presented protection against DNA damage, an effect possibly related to increased hepatic lutein concentrations. However, it must be pointed out that the cause-effect relationship between lutein levels and protection is hypothetical and remains to be demonstrated.

Potencial de fibra alimentar em países ibero-americanos: alimentos, produtos e resíduos / Dietary fiber potential in Iberian-American countries: food, products and residues

The reduced intake of dietary fiber (DF) has been associated with the increase in the incidence of several non-transmissible chronic diseases. Recently many researchers from Iberian-American countries have been studying DF of food and industrial residues in order to improve technological knowledge about concentrates production as well as the development and test of enriched products originated from regional food. The present study aimed to evaluate the regional DF potential based on compilation of data about this nutrient. There is great availability of regional and traditional food with considerable DF amounts as we may find in fruits, vegetables and cereals and legumes. Concentrated sources of DF obtained from different industrial residues were characterized and evaluated making possible their utilization in food enrichment. Cookies added to corn residues (16.8 per cent DF in integral weight) in Colombia, and pasta added to lupine fiber in Chile (11.2 per cent) are examples of tested enriched products. Products like bread with whole wheat (12 per cent), products for especial uses as well as pills of citric DF (55 per cent) and food for enteral diets (1-1.9 per cent) are already available on Cuba market. The dietary fiber contents presented in this work allow us to have an idea of the potential of such nutrient in Iberian-American countries. Such potential has been proved to be considerably representative. It is worth to inform that the complete DF database is available on the CYTED X1.6/CNPq Project Web site (http://www.fcf.usp.br/cytedxi16). It provides data on 817 regional, traditional and not conventional foods, that can be searched and utilized by professional from different areas.

Acao anti-nutricional das fito-hemaglutininas de Phaseolus vulgaris, L. / Antinutritional effect of the phytohemagglutinins of Phaseolus vulgaris, L.

Os autores estudaram, em ratos, o efeito da ingestao das lectinas isoladas dos feijoes (Phaseolus vulgaris, L.) das variedades Jalo e Rico 23. Diferentes quantidades de lectinas foram adicionadas a dietas experimentais, variando-se a quantidade de proteinas de 5% ate 20%. A adicao de 1% das lectinas do feijao Jalo provocou diminuicao no crescimento dos ratos, alterou a glicemia serica e, tambem, reduziu a atividade da maltase e da invertase da mucosa intestinal. Efeitos semelhantes foram verificados com 5% de lectinas obtidas do feijao Rico 23. Concentracoes elevadas de proteinas na racao (20%) parece compensar eventuais alteracoes metabolicas

Propriedades nutricionais e toxicologicas da Canavaglia gladiata cultivada no Brasil. / Nutritional and toxicological properties of Canavalia gladiata cultivated in Brazil

Os autores estudaram as atividades aglutinante e mitogenica da foto-hemoglutinina e o valor da proteina da Canavalia gladiata DC. valor biologico da proteina foi de 30% em relacao ao padrao de caseina e quando suplementada com metionina alcancou somente 50%

Efeito da ingestao de fracoes de soja crua ou autoclavada sobre a tiroide de ratos. / Effect of the ingestion of soybean fractions raw or treated with autoclave on thyroid

No presente trabalho estudou-se o efeito sobre a tiroide de ratos, da ingestao de fracoes cruas ou autoclavadas, obtidas de farinha de soja por extracao aquosa e precipitacao isoelectrica. A ingestao por 16 dias da fracao crua soluvel em agua causou aumento de 40% no peso da tireoide, reducao semelhante na porcentagem de captacao de 131I e um aumento na capacidade serica de ligacao da triiodotironina radioativa. Esse efeito foi termolabil. A mesma fracao porem autoclavada causou uma reducao na captacao e na capacidade serica de ligacao de triiodotironina. Em ensaios de 29 dias essa mesma fracao provocou aumento de captacao de 30% e uma alteracao dos hormonios tireoidianos representados principalmente por um aumento de velocidade de sintese de T3 e T4 respectivamente de uma e duas vezes, reducao da relacao T3/T4 e um aumento de relacao MIT/DIT