Submitted by Verena Bastos (verena@uefs.br) on 2015-07-24T13:45:42Z No. of bitstreams: 1 ?UDER REIS DIAS -DISSERTA??O MESTRADO 2013 -RGV.pdf: 1805178 bytes, checksum: fa9b0a71b8366540b825499da5adb0f8 (MD5) / Made available in DSpace on 2015-07-24T13:45:42Z (GMT). No. of bitstreams: 1 ?UDER REIS DIAS -DISSERTA??O MESTRADO 2013 -RGV.pdf: 1805178 bytes, checksum: fa9b0a71b8366540b825499da5adb0f8 (MD5) Previous issue date: 2013-10-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The Melastomataceae family comprises 4,570 species in approximately 180 genera present in all tropical and subtropical regions of the planet. This family, in Brazil, is the sixth largest family of Angiosperms, with over 1500 species. The genus Tibouchina presents, approximately, 350 species, however, are poorly studied. The Tibouchina pereirae Aubl., a shrub, is popularly used for the treatment of kidney diseases. In this study, we show the antioxidant and antinociceptive effects of T. pereirae. The hexane (EHTP), ethanol (EETP) and aqueous (EATP) extracts were obtained by maceration from the aerial parts of T. pereirae. The flavonoid rich fraction (FFTP) was obtained from fractionation of EHTP. The analysis of FFTP by HPLC-DAD and HPLC-MS/MS led to characterization of these flavonoids. The antioxidant activity of extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay system and the in vivo experiments were conducted on Swiss mice using the acetic acid-induced writhing test and the formalin-induced pain test. Results showed that extracts (EHTP, EETP and EATP) and FFTP present antioxidant activity, when compared to standard butylated hydroxytoluene (BHT) and ascorbic acid (AA). The EHTP and FFTP (i.p., 100mg/Kg) reduced the nociception produced by acetic acid by 90,36% and 94,74%, respectively. The FFTP reduced the formalin effects in both phases by 54, 35% and 92,05%, while the EHTP only protected the second phase by 83,39%. / A fam?lia Melastomataceae apresenta cerca de 4.570 esp?cies, distribu?das em, aproximadamente, 180 g?neros presentes em todas as regi?es tropicais e subtropicais do planeta, sendo que no Brasil ? a sexta maior fam?lia de angiospermas, com mais de 1500 esp?cies. O g?nero Tibouchina possui aproximadamente 350 esp?cies, por?m s?o muito pouco estudadas, sendo que a esp?cie Tibouchina pereirae Aubl. ? popularmente utilizada para o tratamento de problemas renais. Nesse estudo, foram avaliadas as atividades antioxidante e antinociceptiva de T. pereirae. Foram obtidos os extratos hex?nico (EHTP), etan?lico (EETP) e aquoso (EATP) a partir da macera??o das partes a?reas de T. pereirae. A fra??o rica em flavonoides (FFTP) foi obtida a partir do fracionamento do EHTP. A an?lise por CLAE-DAD e CLAE-EM/EM desta fra??o possibilitou caracterizar estes flavonoides. A atividade antioxidante dos extratos foi avaliada utilizando o sistema de ensaio 2,2-difenil-1-picrilhidrazil (DPPH) e os experimentos in vivo foram realizados em camundongos Swiss utilizando os testes de contor??o abdominal induzida por ?cido ac?tico e da formalina. Os resultados obtidos demonstraram que o EHTP, EETP e EATP, assim como a fra??o FFTP apresentaram atividade seq?estradora radicalar, quando comparados aos padr?es butilhidroxitolueno (BHT) e ?cido asc?rbico (AA). O EHTP e a FFTP reduziram a nocicep??o induzida pelo ?cido ac?tico em 90,6% e 94,74%, respectivamente. A FFTP reduziu os efeitos da formalina em ambas fases em 54,35% e 92,05%, respectivamente, enquanto que o EHTP foi ativo somente na segunda fase do teste, com uma redu??o no tempo de lambida de 83,39%.