Anti-Mycobacterial Activity of Medicinal Plant Extracts Used in the Treatment of Tuberculosis by Traditional Medicine Practitioners in Uganda

Abstract

Tuberculosis (TB) remains a public health challenge and one of the leading causes of death worldwide. TB is preventable and curable. However, treatment of tuberculosis has continued to be difficult as a result of rapid increase of multidrug and extensively drug resistant strains of Mycobacterium tuberculosis. Medicinal plants have for centuries been traditionally used in treatment of tuberculosis and similar ailments. They possess antimicrobial properties which render them a new hope as a source of novel bioactive leads in the development of antimycobacterial agents. In this study, 2 plant species commonly used traditionally in Uganda for treatment of tuberculosis, Zanthoxylum leprieurii and Rubia cordifolia were screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis strains; pan sensitive MTB H37Rv, Rifampicin resistant TMC 331 strain and two wild strains (one rifampicin resistant and another one rifampicin susceptible). Antimycobacterial activity of aqueous, ethanolic and methanolic plant extracts was determined using Resazurin Microtiter Assay (REMA). Both plant extracts exhibited significant in vitro antimycobacterial activity against all strains of Mycobacterium tuberculosis. Minimum inhibitory concentrations (MIC) of methanolic crude extracts of both plants ranged from 23.4 μg/mL to 187.5 μg/mL. Comparatively, methanol extracts of both plants possessed superior antimycobacterial activity against all Mycobacterium tuberculosis strains. Our findings indicated that both plants exhibited activity against susceptible and re-

Combination Activity of Standard Antituberculosis Drugs and Extracts of Medicinal Plants Commonly Used in Traditional Treatment of Tuberculosis in Uganda

“…This nding was consistent with other standard anti-TB drugs studied against MDR strains. This is in tandem with other previous studies that indicated that extracts of Z. leprieurii and R. cordifolia inhibited the growth of the MDR strain of Mycobacterium tuberculosis [4,20,22].…”

“…Therefore, there is a global imperative to discover and develop new and e cacious antituberculosis agents, which should be an urgent biomedical priority [18,19]. The plants selected in the current study are commonly used in Ugandan traditional medicine to treat tuberculosis and related ailments and have also been studied for their antimycobacterial activity against different strains of Mycobacterium tuberculosis [4,10,20]. However, little is known about the effects of combination of medicinal plants and conventional antituberculosis drugs.…”

“…Patients with MDR-TB are treated with a regimen of four to ve anti-TB drugs for a period of greater than 15 months after a negative culture is obtained [3]. This long duration, accompanied by frequent serious adverse effects, leads to poor compliance and cessation of treatment [4,5].…”