Made available in DSpace on 2014-12-17T14:10:24Z (GMT). No. of bitstreams: 1 AlineMGCO_DISSERT.pdf: 3644884 bytes, checksum: e2e3e578d2fb797531853d76567fdc2b (MD5) Previous issue date: 2011-03-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Resistance of Plasmodium falciparum to the usual antimalarials, as well as their adverse effects and high cost, has led to the search of new drugs against malaria. Several of these have been developed from medicinal plants based on ethnopharmacology, including the most widely used antimalarials today: quinine and artemisinin. In the present study schizonticide activity of extracts and fractions of a number of medicinal plants from the Caatinga and Amazon biomes were assessed based on ethnopharmacological and chemosystematic information. These included Ximenia americana, Maytenus rigida, Sideroxylon obtusifolium, Stryphnodendro coriaceum, Bowdichia virgiliodes, Schinopis brasiliensis and Picrolemma sprucei, the last, an Amazon species. Antimalarial tests of blood schizonticides were conducted in Swiss mice infected with P. berghei and in vitro against P. falciparum. In vitro cytotoxicity studies were carried out using HeLa, CHO, 3T3, Raw and HEPG2 cell lines. Except for X. americana, all species exhibited in vivo or in vitro antimalarial activity, inhibiting parasitic growth by up to 79%. Extracts exhibited moderate toxicity with dosedependent kinetics. In this sense, ethnopharmacological and chemosystematic approaches were shown to be useful and promising tools in the search of new drugs. These findings represent a significant contribution to scientific knowledge of the antimalarial potential of Brazilian flora, thereby opening perspectives for the development of new antimalarials / A resist?ncia do Plasmodium falciparum aos antimal?ricos usuais, bem como os seus efeitos adversos e custo elevado, tornam necess?ria a busca de novos medicamentos contra a mal?ria. Diversos f?rmacos foram descobertos a partir de plantas medicinais com base na etnofarmacologia, inclusive os antimal?ricos mais usados atualmente; quinina e artemisinina. Neste trabalho foi avaliada a atividade esquizonticida de extratos e fra??es de algumas plantas medicinais dos Biomas da Caatinga e Amaz?nico a partir de um referencial etnofarmacol?gico e de quimiossistem?tica. S?o elas: Ximenia americana, Maytenus rigida, Sideroxylon obtusifolium, Stryphnodendro coriaceum, Bowdichia virgiliodes, Schinopis brasiliensis e Picrolemma sprucei, sendo esta ?ltima, uma esp?cie amaz?nica. Os testes antimal?ricos de esquizonticidas sangu?neos foram feitos em camundongos Swiss infectados com P. berghei e in vitro contra o P. falciparum. Estudos de citotoxicidade in vitro foram realizados utilizando as linhagens celulares HeLa, CHO, 3T3, Raw e HEPG2. A excess?o da X. americana, todas as esp?cies apresentaram atividade antimal?rica in vivo ou in vitro, inibindo o crescimento do parasito em at? 79%. Os extratos exibiram toxicidade moderada com cin?tica de atividade dose-dependente. Nesse contexto, a abordagem etnofarmacol?gica associada ao perfil quimiossistem?tico, se mostram ferramentas ?teis e promissoras na busca de novos f?rmacos, permitindo contribuir significativamente para o conhecimento cient?fico do potencial antimal?rico da flora brasileira e deste modo, abrir perspectivas para o desenvolvimento de novos antimal?ricos