2015-05-282009-02-18SANTOS, Lívia Mara. Obtenção de proantocianidinas do barbatimão e avaliação da toxicidade sobre células de tumor mamário humano MDA-MB-435 e MCF-7. 2009. 52 f. Dissertação (Mestrado em Ciências Farmacêuticas) - Universidade Federal de Alfenas, Alfenas, MG, 2009 .https://repositorio.unifal-mg.edu.br/handle/123456789/302The aim of the present study was to isolate proanthocyanidins from barbatimão leaves and evaluate its cytotoxic activity to MCF-7 (ER+) e MDA-MB-435 (ER-) cells. The proanthocyanidins were isolated from the aqueous fraction of barbatimão leaves using Sephadex LH-20 column chromatography and methanol (10-100%) and acetone (70%) as eluents. The proanthocyanidins presence in the obtained fractions was monitored by thin layer chromatography and it revealed that the methanol 100% eluted fraction (used in the experiments) exhibited the highest content of proanthocyanidins. The acid depolimerization allowed quantifying the procyanidins in the sample and the HPLC analysis revealed the presence of gallic acid, procyanidin dimmer B1 and (-)-epicatechin-3-O-gallate. The fraction exhibited antioxidant activity, being the total antioxidant capacity 470.28 ± 14.36 mg ascorbic acid/g of fraction. The 50%DPPH free radical scavenging activity was obtained with 12 μg/ml and the maximum protein oxidation inhibitory activity was achieved with 50 μg/ml fraction. The fraction was cytotoxic to breast cancer MCF-7 and MDA-MB-435 cells. Cell fraction treatment enhanced the reducing MTT activity that indicates increased cell viability. However, the morphological analysis showed intense cytoplasmic vacuolization in a dosedependent manner. The vacuoles accumulated MTT, which seems to be consistent with autophagic vacuoles. Other morphological changes observed after cell treatment include cell lost of typical morphology, chromatin condensation (mainly pyknosis), membrane blebbing and after 48 h-treatment there was prominently cell shrinkage. No DNA-laddering formation, typical of apoptosis, was obtained after cell treatment. The results seem to indicate that the isolated fraction could induce autophagy in both studied breast cancer cell lines. Autophagy could enhance the effects of antitumor chemotherapy that can be useful in anti-cancer therapy and barbatimão leaf seems to be a valuable source of bioactive substances.application/pdfAcesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/Neoplasias da MamaProantocianidinasStryphnodendron adstringensCIENCIAS DA SAUDE::FARMACIADissertaçãoGouvêa, Cibele Marli Cação Paiva