Atividade antibacteriana de extratos de folhas de Montrichardia linifera (Arruda) Schott (Araceae) / Antibacterial activity of leaf extracts of Montrichardia linifera (Arruda) Schott (Araceae)

RESUMO O uso de plantas medicinais no tratamento de doenças é uma estratégia antiga utilizada por praticamente todas as populações do mundo, e, embora novos antibióticos tenham sido desenvolvidos para o controle de micro-organismos infecciosos, às vezes são ineficazes. Diversos extratos de plantas medicinais têm efeitos antimicrobianos, principalmente quando associados à antibióticos de uso clínico, representando alternativa terapêutica para doenças infecciosas. Montrichardia linifera, conhecida popularmente como aninga, é espécie macrófita, aquática emergente de hábito herbáceo, pertencente a família Araceae e ocorre em áreas alagáveis. A utilidade farmacológica desta espécie é diversificada tendo sido relatada como cicatrizante, antirreumático, antidiurético e expectorante. Devido à relevância no campo etnofarmacológico, ampla utilização na medicina popular e escassez de trabalhos relacionados à atividade antibacteriana desta espécie, objetivou-se com este trabalho avaliar a atividade antibacteriana de extratos alcoólicos de folhas de Montrichardia linifera, coletadas na margem do rio Igaraçu, Parnaíba-PI. O extrato foi testado em oito cepas de bactérias: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa. Foram utilizadas as técnicas de verificação da formação de halos de inibição e determinação das concentrações inibitórias e bactericidas mínimas. Os testes antibacterianos evidenciaram como principais resultados que o extrato metanólico seco (EMS), extrato metanólico fresco (EMF), e o extrato etanólico seco (EES), apresentaram ação antibacteriana, enquanto o extrato etanólico fresco (EEF) não apresentou atividade para as bactérias testadas. O EMS foi o mais eficiente, inibindo o crescimento bacteriano na concentração de 200 μg/mL para E. faecalis, 400 μg/mL para S. aureus, 400 μg/mL para S. epidermidis e 2.000 μg/mL para P. aeruginosa. O EMF obteve CIM de 2.000 μg/mL para E. faecalis e EES obteve CIM de 250 μg/mL para E. faecalis. Os resultados demonstraram que M. linifera constitui fonte eficiente de compostos bioativos antibacterianos. Os estudos sobre as propriedades farmacológicas de plantas da família Araceae são escassos, e os resultados deste trabalho são pioneiros em relação a atividade antibacteriana desta espécie.

ABSTRACT For a long time, medicinal herbs have been used in the treatment of diseases by almost all populations in the world, and although new antibiotics have been developed for the control of infectious micro-organisms, they are sometimes ineffective. Many herbal extracts have antimicrobial effects and represent a potential alternative therapy for infectious diseases, especially when associated with the clinical use of antibiotics. The Montrichardia linifera, popularly known as Aninga, is a robust, herbaceous, emergent aquatic macrophyte belonging to the Araceae family, appearing along rivers and stream margins in the tropical America. The pharmacological application of this species are several ones, having been reported to own a healing, antirheumatic, anti-diuretic and expectorant effect. Due to the relevance in the ethnopharmacological field, the spread use in popular medicine and the few researches related to the antibacterial activity of this specie, the study aimed to evaluate the antibacterial activity of alcoholic leaf extracts of plants of Montrichardia linifera collected along the margins of Rio Igaraçu, Parnaíba, Piauí, Brazil. The extract was tested in eight strains of ATCC bacterial standards: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa. The verification techniques used were the formation of inhibition halos, and the determination of minimum inhibitory and bactericidal concentrations (MIC). The antibacterial tests showed, as main results, that dried methanol extract (EMS), fresh methanol extract (EMF) and dry ethanol extract (EES) exhibited antibacterial activity, while the fresh ethanol extract (EEF) was inactive against the tested bacteria. The EMS was the most efficient one, inhibiting bacterial growth at a concentration of 200 µg/mL for E. faecalis, 400 µg/mL for S. aureus 400 µg/mL for S. epidermidis and 2.000 µg/mL for P. aeruginosa. The EMF obtained a MIC of 2.000 µg/mL for E. faecalis and EES obtained a MIC of 250 µg/mL for E. faecalis. The results showed that M. linifera is an efficient source of bioactive antibacterial compounds. Studies about the pharmacological properties of plants of the family Araceae are scarce, and the results of this work are pioneer in regard to the antibacterial activity of this species.

The web and the structure of taxonomy.

An easily accessible taxonomic knowledge base is critically important for all biodiversity-related sciences. At present, taxonomic information is organized and regulated by a system of rules and conventions that date back to the introduction of binomial nomenclature by Linnaeus. The taxonomy of any particular group of organisms comprises the sum information in the taxonomic literature, supported by designated type specimens in major collections. In this article, the way modern means of disseminating information will change the practice of taxonomy, in particular the Internet, is explored. Basic taxonomic information, such as specimen-level data, location of types, and name catalogues are already available, at least for some groups, on the Web. Specialist taxonomic databases, key-construction programs, and other software useful for systematists are also increasingly available. There has also been a move towards Web-publishing of taxonomic hypotheses, though as yet this is not fully permitted by the Codes of Nomenclature. A further and more radical move would be to transfer taxonomy completely to the Web. A possible model of this is discussed, as well as a pilot project, the "CATE" initiative, which seeks to explore the advantages and disadvantages of such a move. It is argued that taxonomy needs to forge better links with its user-communities to maintain its funding base, and that an important part of this is making the products of its research more accessible through the Internet.

A preliminary study of genetic variation in populations of Monstera adansonii var. klotzschiana (Araceae) from North-East Brazil, estimated with AFLP molecular markers.

BACKGROUND AND AIMS: This study sought genetic evidence of long-term isolation in populations of Monstera adansonii var. klotzschiana (Araceae), a herbaceous, probably outbreeding, humid forest hemi-epiphyte, in the brejo forests of Ceará (north-east Brazil), and clarification of their relationships with populations in Amazonia and the Atlantic forest of Brazil. METHODS: Within-population genetic diversity and between-population dissimilarity were estimated using AFLP molecular markers in 75 individuals from eight populations located in Ceará, the Brazilian Atlantic Forest and Amazonia. KEY RESULTS: The populations showed a clinal pattern of weak genetic differentiation over a large geographical region (F(ST) = 0.1896). A strong correlation between genetic and geographical distance (Mantel test: r = 0.6903, P = 0.002) suggests a historical pattern of isolation by distance. Genetic structure analysis revealed at least two distinct gene pools in the data. The two isolated Ceará populations are significantly different from each other (pairwise Phi(PT) = 0.137, P = 0.003) and as diverse (Nei's gene diversity, average H(e) = 0.1832, 0.1706) as those in the Atlantic and Amazon forest regions. The population in southern Brazil is less diverse (Nei's gene diversity, average H(e) = 0.127) than the rest. The Ceará populations are related to those of the Atlantic forest rather than those from Amazonia (AMOVA, among-groups variation = 11.95 %, P = 0.037). CONCLUSIONS: The gene pools detected within an overall pattern of clinal variation suggest distinct episodes of gene flow, possibly correlated with past humid forest expansions. The Ceará populations show no evidence of erosion of genetic diversity, although this was expected because of their isolation. Their genetic differentiation and relatively high diversity reinforce the importance of conserving the endangered brejo forests.

Population differentiation and species cohesion in two closely related plants adapted to neotropical high-altitude 'inselbergs', Alcantarea imperialis and Alcantarea geniculata (Bromeliaceae).

Isolated granitic rock outcrops or 'inselbergs' may provide a window into the molecular ecology and genetics of continental radiations under simplified conditions, in analogy to the use of oceanic islands in studies of species radiations. Patterns of variability and gene flow in inselberg species have never been thoroughly evaluated in comparison to related taxa with more continuous distribution ranges, or to other species in the same kingdom in general. We use nuclear microsatellites to study population differentiation and gene flow in two diploid, perennial plants adapted to high-altitude neotropical inselbergs, Alcantarea imperialis and Alcantarea geniculata (Bromeliaceae). Population differentiation is pronounced in both taxa, especially in A. imperialis. Gene flow in this species is considerably lower than expected from the literature on plants in general and Bromeliaceae in particular, and too low to prevent differentiation due to drift (N(e)m < 1), unless selection coefficients/effect sizes of favourable alleles are great enough to maintain species cohesion. Low gene flow in A. imperialis indicates that the ability of pollinating bats to promote gene exchange between inselbergs is smaller than previously assumed. Population subdivision in one inselberg population of A. imperialis appears to be associated with the presence of two colour morphs that differ in the coloration of rosettes and bracts. Our results indicate a high potential for inselbergs as venues for studies of the molecular ecology and genetics of continental radiations, such as the one that gave rise to the extraordinary diversity of adaptive strategies and phenotypes seen in Bromeliaceae.

The Latina Breast Cancer Control Study, year one: factors predicting screening mammography utilization by urban Latina women in Massachusetts.

This study identifies factors associated with screening mammography utilization for Latina women age 40 and older in two Massachusetts cities, who are predominantly of Caribbean origin. It is a cross-sectional survey based on an area probability sample, using bilingual Latina interviewers. Sixty-one percent of the sample was Latina, 99% of whom were interviewed in Spanish. Ethnicity, educational attainment, and acculturation were unrelated to recent screening. While distinct healing traditions were found among some Latinas, their use was unrelated to screening. Higher fatalism scores had a bivariate association with lower probability of screening. In a logistic regression, predictors were having health insurance or access to free care; having discussed mammography with a physician in the past 2 years; the difference between 67 and respondent's age (negative coefficient); and city of residence. Having a regular source of care was a predictor when substituted for insurance status. Insurance status and age principally determine whether subjects are screened, mediated by access to physician services and whether physicians recommend screening. Results suggest that universal medical insurance, and efforts to influence physician practices, are key to promoting screening mammography among this population.