In vivo evaluation of anticlastogenicity of extracts from medicinal plants of Miconia genus using the micronucleus test <br> Avaliação 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 suplementação 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 obtidos mostraram que nenhum dos extratos associados à CPA apresentou efeito citotóxico e somente os extratos de M. rubiginosa, M. stenostachya mostraram efeito protetor ao DNA. A análise química dos extratos mostrou que as quatro espécies estudadas contêm, principalmente, flavonóides, compostos fenólicos e taninos. A caracterização fitoquímica desses extratos poderia contribuir para elucidação do efeito protetor apresentado somente pelas espécies M. rubiginosa e M. stenostachya, além de possibilitar o estudo de outras possíveis atividades terapêuticas

Mutagenicidade de duas espécies do gěnero Alchornea avaliadas através de ensaios com Salmonella microssomo e teste do micronúcleo

Some species of the plant genus Alchornea (family Euphorbiaceae) are widely used in popular medicine, mainly in South America and in Africa. Several kinds of biological activity have been seen in the species: antioxidant, antifungal, anti-inflammatory, antibacterial, cytotoxic against tumor cell lines and inhibitory to the replication of HIV-1 and HIV-2. In Brazil, the species Alchornea castaneaefolia Willd. A. Juss. and Alchornea glandulosa Poepp. & Endl. are used by the local population to treat rheumatism, arthritis and muscular pains. In view of the popular use of these plants as medicines and the potential risks from their consumption, we assessed the mutagenic potential of chloroform and methanol extracts of the leaves of these plant species, employing the in vivo micronucleus test and the Ames assay. The data obtained showed that the chloroform extracts were not mutagenic. The methanol extract of A. castaneaefolia was mutagenic to strain TA98 of Salmonella typhimurium and the methanol extract of A. glandulosa to strains TA98 and TA97a. The methanol extracts of both species of Alchornea were mutagenic in vivo at the largest dose employed. The probable mutagenic agents involved were the aglycone quercetin and amentoflavone, present in both species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Absence of mutagenicity in somatic and germ cells of mice submitted to subchronic treatment with an extract of Croton cajucara Benth. (Euphorbiaceae)

The plant Croton cajucara Benth. (Euphorbiaceae) is a medicinal plant from the Brazilian Amazon where it is commonly known as sacaca. The principal compound isolated from C. cajucara stem-bark extracts is the clerodane-type diterpene trans-dehydrocrotonin (DCTN) which presents several biological activities, including antiulcerogenic, anti-inflammatory, hypoglycemic, antimutagenic and antitumoral activity. However, few studies have been carried out to evaluate the therapeutic potential of raw C. cajucara extracts. We studied mutagenicity and antimutagenicity effects of C. cajucara methanol extract using the micronucleus assay in bone marrow cells and the dominant lethal assay in mice submitted to subchronic treatments. The blood testosterone levels of the mice were also measured to assess the effects of the methanol extract on testes function. Statistical analysis of the data obtained in this study showed no statistically significant mutagenicity attributable to C. cajucara stem-bark extracts, nor did such extracts show antimutagenic activity at the concentrations assessed. The testosterone concentration was normal in all the mice studied

Mutagenic effect of native species of the Brazilian Cerrado with anti-ulcerogenic activity

Neea theifera Oerted (Nyctaginaceae), Guapira noxia Linn. (Nyctaginaceae) and Hancornia speciosa Gomes (Apocynaceae) are plant species found in Brazilian Cerrado used popularly for the treatment of gastric ulcers. Here they are assessed for mutagenic activity by analysis of the reverse mutations induced in Salmonella typhimurium strains TA100, TA98, TA102 and TA97a, by extracts of the plants, with and without metabolic activation. Methanol and chloroform extracts of N. theifera and G. noxia and methanolic and aqueous extracts of H. speciosa were tested at five different concentrations. It was found that only the methanolic extract of H. speciosa exhibited a positive mutagenic effect, on strains TA98 and TA100 in the absence of metabolic activation. The phytochemical analysis of the species suggested that condensed tannins are the main compounds responsible for the observed effect