Comparação de efeitos dos extratos de Hypericum perforatum (Hipérico) e de Mentha crispa (Hortelã) em diferentes modelos experiemtais

Several clinic evaluations have been possible with radiobiocomplexes labeled with technetium-99m (99mTc). Some natural and synthetic drugs are capable of to interfere on the labeling of blood constituents with 99mTc, as well as on the biodistribution of radiobiocomplexes. Authors have also reported about the toxicity of several natural products. The aim of this study was to compare the effects of the Mentha crispa (hortelã) and of the Hypericum perforatum (hipérico) in different experimental models. On the labeling of red blood cells (RBC) and plasma and cellular proteins with 99mTc, both extracts were capable of to decrease the radioactivity percentage on the cellular compartment and on the fixation on plasma and cellular proteins. On the morphometry of the RBC, only the hortelã was capable to alter the shape and the perimeter/area ratio of the RBC. On the biodistribution of the radiobiocomplex sodium pertechnetate (Na99mTcO4), the hortelã increased the Na99mTcO4 distribution in the kidney, spleen, liver and thyroid, meanwhile the hipérico decreased the Na99mTcO4 distribution in the bone, stomach, lungs and thyroid, and increased the Na99mTcO4 distribution in the pancreas. On the bacterial cultures survival, the hipérico was capable of to protect the bacteria against the stannous chloride (SnCl2) effect. The hipérico did not alter the topology of plasmidial DNA and did not protect the plasmidial DNA against the SnCl2 action. Probably, the effects presented by both extracts could be due to chemical compounds of the extracts that could alter the morphology of the RBC and the plasma membrane ions transport, and/or by phytocomplexes that could be formed with different effects dependent on the biological system considered

Caracterização genética e in situ de Gossypium barbadense na região norte do Brasil

Brazil has been considered one of the diversity centers of Gossypium barbadense species. It is believed that a relatively big erosion genetic process occurs with the species, due to economic, cultural and agricultural problems. A local diagnostic about species situation is the first step for reducing the diversity loss and establishing conservation strategies in situ. This research aimed the identification of the presence of Gossypium populations, characterization, determination of the main risks and collection of the accesses to store in germoplam banks, in Para and Amapa States. Expeditions were conducted in November 2004. An interview was carried out with the plant proprietor for characterizing in situ of G. barbadense species and of the environment where the plants were inserted. On hundred seventy nine plants in 22 municipal districts were collected in Para State and 117 plants in nine municipal districts in Amapa State. The majority of plants belong to G. barbadense species (98% in Amapa and 94% in Para). Plants occur in back yards, beside roads and spontaneously. That ones from back yards were more abundant (97% in Amapa and 95% in Para) and maintained as medicinal plants as the principal reason. Plants in natural environments in both states evaluated were not found, therefore, the creation of reserves and the application of others conventional methods of maintenance in situ are not applicable. The plant proprietors do not use to store or process seeds. Seed storage was reported as a practice by only 1% of the plant proprietors from Para and 11% from Amapa. The most plants collected were from two to three years of age (58% in Amapa and 93% in Para). As conclusions G. barbadense is the species most spread in the two studied states and are found in back yards. In Amapa State the botanical variety barbadense or Quebradinho is predominant, whereas in Para State the predominant variety is brasiliense or Rim-de-boi. Adequate conservation of thestudied species must be carried out in germoplasm collections maintained ex situ

Efeito da seca na dinâmica dos grupos funcionais fitoplanctônicos em reservatórios eutróficos do semiárido

Reservoirs are the main sources of surface water in Brazil´s semiarid region. The majority of these water supplies, however, are compromised by eutrophication. A severe drought in 2012 contributed to significant losses in water volume, influencing the availability of resources (nutrients and light) for phytoplankton. The aim of this study is to understand the dynamics of the functional groups of phytoplankton and the factors that affect them during a severe drought in the semiarid reservoirs of the northeast. We therefore studied the Dourado, Gargalheiras and Passagem das Traíras reservoirs in Rio Grande do Norte from January 2012 to January 2013. The effect of drought favoured homogeneity within the reservoir, in relation to biotic and abiotic variables, notably the absence of water supply given the lack of flow from its tributaries (intermittent river). The phytoplankton functional groups of bloomforming cyanobacteria (SN, S1 and M) dominated throughout the year 2012, in both the shallow and deep areas of the three reservoirs studied. The groups were related to high concentrations of volatile solids, total phosphorus and ammonia, and high turbidity. Cylindrospermopsis raciborskii (SN group) was the species with the greatest biomass in the three reservoirs. M group (Sphaerocavum brasiliense) performed better in shallow waters with more available phosphorus. Our data showed that high concentrations of nutrients and low availability of light, besides the stability of the water column due to lack of flow and the system´s high residence time, favoured the dominance of bloom-forming cyanobacteria groups, especially those tolerant to shadow