Paepalanthus spp: antimycobacterial activity of extracts, methoxylated flavonoids and naphthopyranone fractions

Paepalanthus spp., Eriocaulaceae, are native plants from Brazil known as "sempre-vivas" (everlasting flowers). In this work, we evaluated the potential anti-mycobacterial activity of two methoxylated flavonoids (flavonoid 7-methylquercetagetin and 7-methylquercetagetin-4'-O-β-D-glucopyranoside) isolated and identified from P. latipes and the naphthopyranone fractions from P. bromeliodes ethanolic extracts. The MIC value of 500 µg/mL was verified for all compounds tested against M. tuberculosis H37Rv. For M. avium, the MIC value ranged from 1000-2000 µg/mL excepting to naphthopyranone fractions with MIC of 500 µg/mL. This is the first report of activity determination of Paepalanthus spp. flavonoids activity against Mycobacterium tuberculosis and M. avium.

In vitro anti-Mycobacterium tuberculosis activity of some Brazilian "Cerrado" plants / Atividade anti-Mycobacterium tuberculosis in vitro de algumas plantas do "Cerrado" Brasileiro

O objetivo deste trabalho foi realizar uma seleção de algumas plantas de uma determinada região Brasileira com atividade contra Mycobacterium tuberculosis. Extratos clorofórmicos e metanólicos de 37 espécies de plantas distribuídas em 17 famílias do "Cerrado" Brasileiro foram avaliadas contra M. tuberculosis H37Rv e a Concentração Inibitória Mínima (CIM) foi determinada pelo uso do Microplate Alamar Blue Assay (MABA). Extratos brutos de dezesseis plantas apresentaram valor de CIM < 125 µg/mL e três de 31,2 µg/mL. Estes resultados sugerem que o "Cerrado" Brasileiro deve possuir um recurso de plantas com constituintes ativos anti-M. tuberculosis que podem ser extraídos por solventes polares e apolares.

The aim of this work was to carry out a screening of some plants of this Brazilian region with activity against Mycobacterium tuberculosis. Chloroform and methanol extracts of 37 plant species distributed among 17 families from Brazilian "Cerrado" which were tested against M. tuberculosis H37Rv and the Minimum Inhibitory Concentration (MIC) was determined by the use of Microplate Alamar Blue Assay (MABA). Crude extracts from sixteen plants showed MIC value of < 125 µg/mL and three 31.2 µg/mL. These results suggest that the Brazilian "Cerrado" may be a source of plants that have activity anti-M. tuberculosis constituents that can be extracted by polars and apolars solvents.