Anti-coagulase-negative Staphylococcus activity of ethanolic extracts of propolis from two Brazilian regions and synergism with antimicrobial drugs by the E-test method

Propolis is a natural resinous substance collected by bees from vegetal sources and its therapeutic properties have been investigated. In this work, we evaluated the inhibitory activity of ethanolic extracts of propolis (EEP) from the Southeast and South of Brazil on coagulase-negative Staphylococcus (CNS) growth as well as the EEP in vitro synergism with antimicrobial drugs by using the diffusion method (E-test). The EEP chemical characteristics (dry weight, pH, flavonoid and phenolic compounds) were determined. Seven drugs were tested, and synergism was observed between three drugs and Southeast EEP, six drugs and South EEP, and one drug and ethanol control. Ethanolic extracts of propolis from the South of Brazil presented the greatest flavonoid content and synergism rate, while EEP from the Southeast presented the greatest anti-CNS activity and phenolic compound content. Results showed the correlation among anti-CNS activity, synergism rate and chemical characteristics of propolis.

Nutritional composition, phenolic compounds, nitrate content in eatable vegetables obtained by conventional and certified organic grown culture subject to thermal treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of the antimutagenicity of an aqueous extract of Rhizophora mangle L. (Rhizophoraceae), using in vivo and in vitro test systems

An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.

Physiological quality and enzymatic activity of crambe seeds after the accelerated aging test

O crambe é uma cultura promissora para produção de biodiesel, principalmente pelo alto conteúdo de óleo de suas sementes. No entanto, não há metodologias estabelecidas para avaliar a qualidade fisiológica das sementes desta espécie e lotes não podem ser comparados, especialmente por testes de vigor, como o de envelhecimento acelerado. O objetivo da presente pesquisa foi avaliar o efeito da alta temperatura e do período de exposição durante o teste de envelhecimento acelerado na qualidade fisiológica e atividade enzimática de sementes de crambe. Dois lotes de sementes de crambe, cultivar Brilhante, foram analisados por meio dos testes de teor de água, massa de 1.000 sementes, germinação, primeira contagem, condutividade elétrica, atividade enzimática (peroxidase e superóxido dismutase) e comprimento de plântulas. As avaliações foram conduzidas antes e após o envelhecimento acelerado, que foram testadas diferentes temperaturas (38, 40 e 42ºC) e períodos de exposição (24, 48 e 72h). O delineamento experimental foi o inteiramente casualizado com quatro repetições. Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey (p < 0.05). O teste de Dunnet (p < 0.05) foi utilizado para comparar os valores da testemunha (antes do envelhecimento acelerado) com cada valor médio individualmente. O teste de correlação linear simples também foi aplicado. Conclui-se que a interação temperatura x período de exposição afeta a qualidade fisiológica das sementes e a atividade enzimática e que as melhores condições durante o teste de envelhecimento acelerado são dependentes do genótipo.

Criteria for peanut seed pre-conditioning for the tetrazolium test

The staining pattern of peanut (Arachis hypogaea L.) seeds with a tetrazolium solution was evaluated to determine the adequate conditions of seed quality evaluations. Three seed lots with different vigour levels and similar moisture content were pre-conditioned using the combination of five periods of time (4, 8, 12, 16 and 20 hours) and four temperatures (20, 25, 30 and 35 degrees C) and then exposed to a 1.0% tetrazolium solution for three hours. The moisture content levels of seeds conditioned for 8 hours at the temperatures of 25, 30 or 35 degrees C, for 12 hours at 20 or 25 degrees C and for 16 hours at 20 degrees C, were above 30%. In this range of moisture level, the staining in tetrazolium was clear and uniform, reflecting an appropriate conditioning of the seeds. However, under a practical point of view, the period of 16 hours at 20 degrees C showed to be the best option, since it allows to start the pre-conditioning an late afternoon of one day and submit the seeds for staining in the following morning.

Electrical conductivity of soybean seed and correlation with seed coat lignin content

The effects of soybean genotype and seed coat lignin content on bulk electrical conductivity were investigated. Seeds of nine soybean cultivars were hand harvested at R8 maturation stage in Londrina, PR., Brazil in 1995/96. Seeds were electrical conductivity tested using four replicates of 50 seeds per cultivar soaked in 75 mi of deionized water at 25 degrees C for 24 hours. Seed coat lignin content was determined using the potassium permanganate method. There was a significant relationship (R-2 = 0.84**) between electrical conductivity and seed coat lignin content, the latter being a characteristic that varies among soybean genotypes; the higher the amount of lignin in the seed coat, the lower the levels of seed exudates to the soaking solution and consequently the lower the electrical conductivity. It was concluded that seed soaking electrical conductivity is influenced by the seed coat lignin content, which is a characteristic that varies among soybean genotypes. Additionally, the EC test can be used as a valuable tool in the screening process for this characteristic, which is desirable for genetically improving soybean seed quality.

Application of compression test in analysis of mechanical and color changes in grapefruit juice powder as related to glass transition and water activity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reproductive biology of the neotropical rattlesnake Crotalus durissus from northeastern Brazil: a test of phylogenetic conservatism of reproductive patterns

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rat nephrotoxic nephritis. The relation between the type and intensity of induced histological lesions and the content of antiglomerular basement membrane antibodies of the inoculated serum

Six groups of 6 rats received equal doses (0.8 ml/100 g of body weight) of different rabbit anti rat kidney sera. The titer of anti GBM antibodies in the sera was evaluated by indirect immunofluorescent test in isolated GBM (IIT GBM). Rats of groups 1, 2, 3, 5, 6 received anti rat GBM sera with titers of 1/320, 1/240, 1/160, 1/60, 1/30 respectively. Group 4 received anti rat kidney serum with a titer of 1/80. The rats of group 1 died from 1 to 5 minutes after inoculation and their kidney were congested, with hialine trombi occluding arterioles and glomerular capillaries. The rats of group 2 and one of group 3 died from 2 to 15 days after inoculation and diffuse cortical necrosis was found. The remaining rats were sacrificed 2 months after inoculation. The kidneys were normal in control group; chronic membranoproliferative glomerulonephritis was observed in group 3 and 4, membranoproliferative glomerulonephritis in group 5 and minimal changes in group 6. By immunofluorescence rabbit gammaglobulin was seen in GBM of group 3, 4, 5 and 6. The IIT GBM performed in the eluates of the kidneys revealed the presence of heterologous antibody in groups 1, 2, 3, 4, 5 and 6 and autologous antibody in groups 3, 4 and 5. One concludes that the IIT GBM identifies and quantifies antibodies which have the property of damaging the kidney.