Study on antimycobacterial properties of selected ethnomedicinal plants: An alternative therapeutic choice against multidrug resistant Mycobacterium tuberculosis

To evaluate the antimycobacterial efficacy of 10 ethnomedicinal plants against one clinical isolate of Mycobacterium tuberculosis and the standard TB strain, H37Rv.

A strain of M. tuberculosis was isolated from a patient's sputum sample. It was identified by Ziehl-Neelsen (acid fast staining) method and was cultured on the Lowenstein-Jensen (LJ) medium. Aqueous, ethanol and methanol extracts of 10 plants, Acacia catechu, Acorus calamus, Adhatoda vasica, Aegle marmelos, Andrographis paniculata, Catharanthus roseus, Moringa oleifera, Ocimum basilicum, Vitex negundo and Withania somnifera were prepared. The antimycobacterial properties were evaluated by incorporating the extracts into the LJ medium at concentration of 2.5%, 5%, 10% and 20% volume/volume, prior to inspissation and counting the colony forming units (CFU) after incubation period.

Methanol extracts of A. vasica, and M. oleifera had promising antimycobacterial properties. In general, the methanol extracts were more effective against H37Rv strain, as compared to the clinical isolate. Ethanol extracts of A. vasica, C. roseus, M. oleifera and were also effective in controlling the growth of M. tuberculosis colonies (both H37Rv and clinical isolate) on LJ medium. Particularly, at 20% level ethanol extract of C. roseus, the CFU count was 17 and 19 for the H37Rv strain and for the clinical isolate, respectively

Bacteria do not become resistant to phytochemicals, because of their complex structure. The aim of isolation of a pure phytochemical against MDR TB strains is rational and achievable. Particularly, plants, A. vasica, and M. oleifera, can be further be utilized as anti-tubercular drugs.