Antituberculosis potential of some ethnobotanically selected Malaysian plants

Seventy Malaysian plant species used in traditional medicine to treat respiratory diseases including symptoms of tuberculosis were screened for activity against Mycobacterium tuberculosis H37Rv using Tetrazolium bromide microplate assay. Thirty-six plant species exhibited antituberculosis activity with MICs in the range of 1600–400μg/ml. The results justify, to a certain extent the ethnomedicinal uses of these plants as remedies for symptoms of tuberculosis. Many local plants are used in Malaysian traditional medicine to treat respiratory diseases including symptoms of tuberculosis. The aim of the study was to screen 78 plant extracts from 70 Malaysian plant species used in traditional medicine to treat respiratory diseases including symptoms of tuberculosis for activity against Mycobacterium tuberculosis H37Rv using a colorimetric microplate-based assay. Plant extracts were prepared by maceration in methanol (80%) and antituberculosis screening was carried out using Tetrazolium bromide microplate assay (TEMA) method to determine the minimum inhibitory concentration (MIC). Thirty-eight plant extracts from 36 plant species exhibited antituberculosis activity with MICs in the range of 1600–400μg/ml. The leaf extract of Angiopteris evecta exhibited the highest activity with MIC of 400μg/ml. Five other extracts, namely, Costus speciosus (stem and flower), Piper sarmentosum (whole plant), Pluchea indica (leaf), Pluchea indica (flower), and Tabernaemontana coronaria (leaf) exhibited antituberculosis activity, each with MIC of 800μg/ml. To the best of our knowledge, this is the first report of in vitro high throughput screening of Malaysian medicinal plants for antituberculosis activity. Antituberculosis activity of extracts of some plants justifies, to a certain extent their ethnomedicinal uses as remedies for symptoms of tuberculosis. These results also support the general view that, selecting the plants based on ethnobotanical criteria would enhance the probability of finding species with antituberculosis activity.