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.

Extraction of saponins and toxicological profile of Teucrium stocksianum boiss extracts collected from District Swat, Pakistan

BACKGROUND: The current era is facing challenges in the management of neoplasia and weeds control. The currently available anti-cancer and herbicidal drugs are associated with some serious side effects. Therefore numerous researchers are trying to discover and develop plant based alternative particularly for the rational management of cancer and weed control. Teucrium stocksianum possess antioxidant and analgesic activities. The current study was designed to evaluate crude saponins (CS), methanolic extract and sub-fractions of T. stocksianum for cytotoxic and phytotoxic potentials. CS, methanolic extract and sub-fractions were extracted from powdered plant material using different solvents. Cytotoxic potential of the extracts at a dose of 10, 100 and 1000 µg/ml were evaluated against Brine shrimp's nauplii. Phytotoxic assay also performed at the same concentration against Lemna minor. Etoposide and Paraquat were used as positive controls in cytotoxic and phytotoxic assays respectively. RESULTS: The percent yield of crude saponins was (5%). CS demonstrated tremendous brine shrimp lethality showing < 10 µg/ml LC50. The n-hexane (HF) and chloroform fractions (CF) demonstrated excellent cytotoxicity with 80 and 55 µg/ml LC50 respectively. Whereas the methanolic extract (TSME), ethyl acetate (EAF) and aqueous fractions (AF) revealed moderate cytotoxicity showing 620, 860 and 1000 µg/ml LC50 values respectively. In phytotoxic assay profound inhibition was displayed by HF (96.67%) and TSME (95.56%, 30 µg/ml LC50) against the growth of Lemna minor at 1000 µg/ml respectively. Both CF and EAF demonstrated profound phytoxicity (93.33%) respectively at highest concentration (1000 µg/ml), while AF and CS demonstrated weak phytotoxicity with 1350 and 710 µg/ml LC50 values respectively. CONCLUSION: Cytotoxicity and phytotoxicity assays indicated that the crude saponins, n-hexane and chloroform fractions of T. stocksianum could play a vital role in the treatment of neoplasia and as potential natural herbicides. Therefore these sub-fractions are recommended for further investigation with the aim to isolate novel anti-cancer and herbicidal compounds.

The floristic compositions of vascular epiphytes of a seasonally inundated forest on the coastal plain of Ilha do Mel Island, Brazil

A 3,000 m2 area of seasonally inundated forest on the island of Ilha do Mel (25 degrees 30[quot ] S 48 degrees 23[quot ] W) in Paraná, Brazil, was sampled by collecting plants from all strata, using climbing equipment when necessary. The area harbors 103 species of epiphytes, in 49 genera and 20 families, of which 28 species are pteridophytes and 75 magnoliophytes (64 Liliopsida, 11 Magnoliopsida). The most common families are Orchidaceae, Bromeliaceae, Polypodiaceae and Araceae, and frequent genera are Vriesea, Epidendrum, Maxillaria, Pleurothallis and Prosthechea. Eight families were represented by one species each. Most species were classified as obligatory holoepiphytes (62 %), followed by the relatively more rare preferential holoepiphytes (13 %), facultative epiphytes (11 %), hemiepiphytes (9 %) and accidental epiphytes (6 %).

Se muestreó plantas de todos los estratos en una área de 3 000 m2 de selva estacionalmente inundada en Ilha do Mel (25º30 “S 48º23’ W), Paraná, Brazil. El área tiene 103 especies de epífitas en 49 géneros y 20 familias, de las cuales 28 especies son pteridófitas y 75 magnoliófitas (64 Liliopsida, 11 Magnoliopsida). Las familias más comunes son Orchidaceae, Bromeliaceae, Polypodiaceae y Araceae, y los géneros más frecuentes Vriesea, Epidendrum, Maxillaria, Encyclia y Pleurothallis. Ocho familias solamente están representadas por una especie cada una. La mayoría de las especies son loepífitas obligadas (62 %), seguidas de las relativamente escasas holoepífitas preferenciales (13 %), epífitas facultativas (11 %), hemiepífitas (9 %) y epífitas accidentales (6 %).