Anti-Mycobacterial potential of Tabebuia aurea (Manso) Benth & Hook (Bignoniaceae)
Manisha Agarwal, Seema Chauhan
Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis. The World Health Organization has estimated almost 9 million new cases and 1.4 million TB deaths in 2011. Medicinal plants offer a great hope for curing diseases for many centuries. These have been used extensively as pure compounds or as a crude material. In the present study antibacterial activity of aqueous and alcoholic extracts of stem bark and leaves of Tabebuia aurea (Manso) Benth. & Hook. (Family: Bignoniaceae) was tested against MDR isolates DKU-156 and JAL-1236 of M. tuberculosis, reference susceptible strain M. tuberculosis H37Rv as well as fast growing mycobacterial pathogen M. fortuitum (TMC-1529). The leaves and bark were dried and extracts were prepared using distilled water and ethanol (98%). Reference drug susceptible strain M. tuberculosis H37Rv as control, multi-drug resistant isolates DKU-156, JAL-1236 and fast growing mycobacterial pathogen M. fortuitum (TMC-1529) were used during the present investigation. Antimicrobial assays were performed in Lowenstein Jensen (L-J) medium and Middlebrook 7H9 broth in BacT/ALERT 3D system (Sigma-Aldrich, St. Louis, USA). The aqueous and alcoholic extracts of stem bark and leaves were incorporated in the media. Susceptibility testing of MDR isolates was also performed against streptomycin in the same batch of media for comparison of cfu on drug free controls. The results of the present investigation clearly showed that the aqueous extracts of stem bark were more effective as compared to aqueous and leaf extracts and alcoholic stem bark and leaf extracts.