Antimycobacterial activity of methanol extract from the stem bark of Alan-gium salvifolium against multi-drug resistant mycobacterium tuberculosis

Abstract

Tuberculosis (TB) remains the 2nd leading cause of the major infectious disease in humans and causes considerable morbidity worldwide among millions of people every year. The present study aimed to screen the susceptibility of Mycobacterium tuberculosis to the stem bark of Alangium salvifolium using Luciferase reporter phage assay (LRP). Powdered stem bark of Alangium salvifolium was extracted with methanol, subjected to phytochemical analysis and TLC. Susceptibility of M. tuberculosis was studied by LRP assay at various concentrations (50, 100 and 200 µg/ml). The strains used for the present study are one reference strain M. tuberculosis H37 Rv and 2 clinical isolates one sensitive and the other resistant strain of M. tuberculosis, to Isoniazid, Streptomycin, Ethambutol and Rifampicin. The presence of the phytoconstituents viz., alkaloids, tannins, terpenoids, glycosides and flavonoids in the methanol extract are confirmed by preliminary phytochemical analysis. TLC analysis of methanol extract showed 12 well separated spots with Rf value ranging from 0.2 to 0.9. Methanol extract of A. salvifolium exhibited maximum antimycobacterial activity at higher concentration (200 µg/ml). The proportion inhibition of methanol extract of A. salvifolium against Mycobacterium tuberculosis H37Rv strain were 53.26%, 82.87% and 94.56% at the concentration of 50, 100 and 200 µg/ml respectively. The tested extract showed good microbial sensitivity against Multi drug resistant (MDR) strains. Further phytochemical analysis and identification of lead molecule(s) based on bioassay guided fractionation from the selected plant could serve as complementary alternative therapy for treating tuberculosis.