In vivo evaluation of anticlastogenicity of extracts from medicinal plants of Miconia genus using the micronucleus test Avalia o in vivo da anticlastogenicidade de extratos de plantas medicinais do gênero Miconia através do teste do micronúcleo

The genus Miconia is comprised of approximately 1000 species. For some of them, biological activities have already been described such as the analgesic and the anti-microbial ones. The purpose of this work was to evaluate the possible protective and cytotoxic effects of the methanolic extract from M. albicans, M. cabucu, M. rubiginosa and M. stenostachya and the chloroformic extract from M. albicans in mice bone marrow cells in 540 mg/kg p.c. dose. The extracts were administered by means of forced feeding and the cyclophosphamide (CPA) was applied intraperitonially one hour after supplementation with extracts. All animals were submitted to euthanasia 30 hours after the treatment. The analyzed cells were extracted from mice bone marrow according to protocol described by Schmid (1975). The cytotoxicity of the extracts was evaluated through the percentage of polychromatic erythrocytes (PCE) in 200 erythrocytes (PCE + NCE). Two thousand PCEs of each animal were analyzed and the micronucleated polychromatic erythrocytes (MNPCEs) frequencies were scored. The results obtained indicated that none of the extracts associated with the CPA showed cytotoxic effect and only the extracts of M. rubiginosa and M. stenostachya showed protective effect to DNA. Chemical analyses of the extracts showed that the four species studied contain mainly flavonoids, phenolic compounds and tannins. The phytochemical characterization of these extracts could contribute to elucidate the protective effect presented only by the species M. rubiginosa and M. stenostachya, besides making it possible the study of other therapeutic activities. O gênero Miconia possui aproximadamente 1000 espécies, e para algumas, já foram descritas atividades biológicas como a analgésica e antimicrobiana. Esse trabalho teve como objetivo avaliar os possíveis efeitos protetores e citotóxicos dos extratos metanólicos de M. albicans, M. cabucu, M. rubiginosa e M. stenostachya e do extrato clorofórmico de M. albicans em células da medula óssea de camundongos na dose de 540 mg/kg p.c. Os extratos foram administrados via gavage e a ciclofosfamida (CPA) foi aplicada intraperitonealmente 1h, após a suplementa o com os extratos. Todos os animais foram submetidos à eutanásia 30h após o tratamento. As células analisadas foram retiradas da medula óssea de acordo com protocolo descrito por Schmid (1975). A citotoxicidade dos extratos foi avaliada pela percentagem de eritrócitos policromáticos (PCE) em 200 eritrócitos (PCE + NCE). Foram analisados 2000 PCEs por animal e anotadas as freqüências de MNPCEs. Os resultados obt