Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest. The knowledge of social wasp richness and biology in the Amazonian region is considered insufficient. Although the Amazonas state is the largest in the region, until now only two brief surveys were conducted there. Considering that the systematic inventory of an area is the first step towards its conservation and wise use, this study presents faunal data on social wasp diversity in a 25 km² area of "terra firme" (upland forest) at the Ducke Reserve, Manaus, Amazonas, Brazil. Wasps were collected in the understory, following a protocol of three collectors walking along 60 trails 1,000 m in extension for 16 days between August and October 2010. Methods used were active search of individuals with entomological nets and nest collecting. Fifty-eight species of social wasps, allocated in 13 genera, were recorded; 67% of the collected species belong to Polybia, Agelaia and Mischocyttarus; other genera were represented by only four species or less. The most frequent species in active searches were Agelaia fulvofasciata (DeGeer, 1773), Agelaia testacea (Fabricius, 1804) and Angiopolybia pallens (Lepeletier, 1836). Twelve species were collected in nests. Prior to this study, 65 Polistinae species were deposited at the INPA Collection. Collecting in the study grid, an area not previously sampled for wasps, resulted in an increase of 25% species, and species richness was 86. According to the results, there is evidence that the diversity of social wasps at the Ducke Reserve is even higher, making it one of the richest areas in the Brazilian Amazonia.

In vitro screening of Amazonian plants for hemolytic activity and inhibition of platelet aggregation in human blood

In the present study, different aerial parts from twelve Amazonian plant species found in the National Institute for Amazon Research's (INPA's) Adolpho Ducke Forest Reserve (in Manaus, Amazonas, Brazil) were collected. Separate portions of dried, ground plant materials were extracted with water (by infusion), methanol and chloroform (by continuous liquid-solid extraction) and solvents were removed first by rotary evaporation, and finally by freeze-drying which yielded a total of seventy-one freeze-dried extracts for evaluation. These extracts were evaluated initially at concentrations of 500 and 100 µg/mL for in vitro hemolytic activity and in vitro inhibition of platelet aggregation in human blood, respectively. Sixteen extracts (23 % of all extracts tested, 42 % of all plant species), representing the following plants: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae), exhibited significant inhibitory activity towards human platelet aggregation. A group of extracts with antiplatelet aggregation activity having no in vitro hemolytic activity has therefore been identified. Three extracts (4 %), all derived from Elaeoluma nuda (Sapotaceae), exhibited hemolytic activity. None of the plant species in this study has known use in traditional medicine. So, these data serve as a baseline or minimum of antiplatelet and hemolytic activities (and potential usefulness) of non-medicinal plants from the Amazon forest. Finally, in general, these are the first data on hemolytic and inhibitory activity on platelet aggregation for the genera which these plant species represent.

No presente estudo, partes aéreas obtidas de doze (12) espécies vegetais da Amazônia encontradas na Reserva Florestal Adolpho Ducke (localizada na cidade de Manaus, Estado do Amazonas, Brasil) do Instituto Nacional de Pesquisas da Amazônia foram coletadas, secadas e moídas. Porções dos materiais vegetais em pó foram extraídas com água (por infusão), metanol e clorofórmio (por extração líquido-sólido contínua) e os solventes foram removidos por evaporação rotatória e finalmente liofilização, forneceram um total de setenta e one (71) extratos liofilizados. Esses extratos foram avaliados inicialmente para atividade hemolítica in vitro e atividade inibitória da agregação plaquetária em sangue humano in vitro em concentrações de 500 e 100 µg/mL, respectivamente. Dezesseis (16) extratos (23 % dos extratos testados, 42 % das espécies vegetais) representando as seguintes plantas, apresentaram inibição significativa frente a agregação de plaquetas humanas in vitro: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae). Como principal resultado, um grupo de extratos apresentando atividade inibitória da agregação plaquetária e em que não há atividade hemolítica in vitro foi identificado. Três (3) extratos (4 % do total de extratos testados), todos obtidos a partir de Elaeoluma nuda (Sapotaceae), apresentaram atividade hemolítica. Nenhuma das espécies vegetais nesse estudo tem uso medicinal conhecido. Assim, esses dados servem de linha base ou mínimas das atividades antiplaquetária e hemolítica (e utilidade potencial) de plantas da floresta Amazônica. Finalmente, em geral, esses dados são os primeiros disponíveis sobre ação hemolítica e inibição da agregação plaquetária dos gêneros representados por essas espécies de plantas.