title: Activity of 7-methyljuglone in combination with antituberculous drugs against Mycobacterium tuberculosis.
abstract: The recent increase in the incidence of tuberculosis with the emergence of multidrug-resistant (MDR) cases has lead to the search for new drugs that are effective against MDR strains of Mycobacterium tuberculosis and can augment the potential of existing drugs against tuberculosis. In the present study, we investigated the activities of a naphthoquinone, 7-methyljuglone, isolated from the roots of Euclea natalensis alone and in combination with other antituberculous drugs against extracellular and intracellular M. tuberculosis. Combinations of 7-methyljuglone with isoniazid or rifampicin resulted in a four to six-fold reduction in the minimum inhibitory concentration of each compound. Fractional inhibitory concentration (FIC) indexes obtained were 0.2 and 0.5, respectively, for rifampicin and isoniazid, suggesting a synergistic interaction between 7-methyljuglone and these anti-TB drugs. The ability of 7-methyljuglone to enhance the activity of isoniazid and rifampicin against both extracellular and intracellular organisms suggests that 7-methyljuglone may serve as a promising compound for development as an anti-tuberculous agent.
authors.affiliation: Department of Pharmacology, University of Pretoria, PO Box 2034, Pretoria, 0001, South Africa.
authors.forename: N B
authors.initials: NB
authors.lastname: Bapela
authors.forename: N
authors.initials: N
authors.lastname: Lall
authors.forename: P B
authors.initials: PB
authors.lastname: Fourie
authors.forename: S G
authors.initials: SG
authors.lastname: Franzblau
authors.forename: C E J
authors.initials: CE
authors.lastname: Van Rensburg
mesh_terms: D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D003603:Cytotoxins / Q000032:analysis; D004338:Drug Combinations; D031262:Ebenaceae / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D009285:Naphthoquinones / Q000302:isolation & purification / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D011874:Radiometry
chemical_list: C517013:7-methyljuglone; D000995:Antitubercular Agents; D003603:Cytotoxins; D004338:Drug Combinations; D009285:Naphthoquinones