Anti-tuberculosis activities of the crude methanolic extract and purified fractions of the bulb of Crinum jagus

Abstract

Summary: Tuberculosis (TB) is of great public health burden globally especially in developing countries of Africa and Asia . Current TB regimen involves multiple therapies and of long duration leading to poor patient adherence. There is also the challenge of multidrug resistant TB. Hence, there is a need for discovery of new anti- TB drugs. This study was designed to investigate the in –vitro activity of the crude methanolic extract and chromatographic fractions of the bulb of Crinum jagus against Mycobacterium tuberculosis isolates. The extracts were screened for anti- TB activity against three different M. tuberculosis isolates and a drug susceptible reference strain H37Rv using Lowenstein Jensen (L-J) medium and Middlebrook 7H10agar. The crude extract was prepared using soxhlet extraction apparatus while the purified fractions were obtained by column chromatography. The two media were inoculated with M. tuberculosis strains, after which the crude and purified extracts were added. After 4-6 weeks incubation, colony forming units were counted and percentage inhibition calculated. The crude extract and the purified fractions showed inhibitory activity on all the isolates tested including the reference strain. Fraction 3 showed the highest inhibitory percentage (86%) among the extracts. At a concentration of 1.0mg/ml, the percentage inhibition of fraction 3, rifampicin and isoniazid against M. tuberculosis strain 3 were 83%, 95% and 86% in L-J medium respectively while 86%, 96% and 89% were obtained respectively in Middle brook medium. Results showed that the crude methanolic extract and the purified fractions of the bulb of Crinum jagus exhibited anti-mycobacterial activity which is an indication of promising potential of this plant for the development of anti-tuberculosis agent.

Keywords: Crinum jagus, Chromatographic fractions, Mycobacterium tuberculosis, In-vitro