Ethnopharmacological versus random plant selection methods for the evaluation of the antimycobacterial activity

The municipality of Oriximiná, Brazil, has 33 quilombola communities in remote areas, endowed with wide experience in the use of medicinal plants. An ethnobotanical survey was carried out in five of these communities. A free-listing method directed for the survey of species locally indicated against Tuberculosis and lung problems was also applied. Data were analyzed by quantitative techniques: saliency index and major use agreement. Thirty four informants related 254 ethnospecies. Among these, 43 were surveyed for possible antimycobacterial activity. As a result of those informations, ten species obtained from the ethnodirected approach (ETHNO) and eighteen species obtained from the random approach (RANDOM) were assayed against Mycobacterium tuberculosis by the microdilution method, using resazurin as an indicator of cell viability. The best results for antimycobacterial activity were obtained of some plants selected by the ethnopharmacological approach (50 percent ETHNO x 16,7 percent RANDOM). These results can be even more significant if we consider that the therapeutic success obtained among the quilombola practice is complex, being the use of some plants acting as fortifying agents, depurative, vomitory, purgative and bitter remedy, especially to infectious diseases, of great importance to the communities in the curing or recovering of health as a whole.

Screening of Central and South American plant extracts for antimycobacterial activity by the Alamar Blue test / Triagem de extratos de plantas das Américas Central e do Sul para atividade antimicobacteriana pelo teste do Alamar Blue

Forty eight ethanolic crude extracts and fractions (hexane, dichloromethane, ethyl acetate and n-butanol) from ten Brazilian plants (Leguminosae, Monimiaceae and Verbenaceae), 1 from Costa Rica (Verbenaceae) and 1 from Argentina (Verbenaceae) were screened for anti-mycobacterium activity against Mycobacterium tuberculosis (ATCC-27294H37Rv), by the Alamar Blue test, at a fixed concentration of 100 µg/mL. Out of the forty eight, seven were active at this concentration, corresponding to Lantana trifolia (hexane and dichloromethane extracts from leaves), Vitex cooperi (methanol:water, 1:1 extract from barks), Lippia lacunosa (hexane and dichloromethane extracts from leaves) and Lippia rotundifolia (hexane and dichloromethane extracts from leaves), all from the Verbenaceae family.

Quarenta e oito extratos brutos etanólicos e frações (em hexano, diclorometano, acetato de etila e n-butanol) de dez plantas brasileiras pertencentes às famílias Leguminosae, Monimiaceae e Verbenaceae; uma da Costa Rica (Verbenaceae) e uma da Argentina (Verbenaceae) foram ensaiados para verificação da atividade anti-micobacteriana contra Mycobacterium tuberculosis (ATCC-27294H37Rv), pelo teste do Alamar Blue, a uma concentração fixa de 100 µg/mL. Dentre os quarenta e oito extratos e frações estudados, sete mostraram-se ativos na concentração ensaiada - frações em hexano e diclorometano de folhas de Lantana trifolia, extrato em metanol:água, 1:1 de cascas de Vitex cooperi, frações em hexano e diclorometano de folhas de Lippia lacunosa e de Lippia rotundifolia, sendoque todas essas plantas pertencem à família Verbenaceae.