Efficacy of the herbicide trifluralin against four P-glycoprotein-expressing strains of Leishmania.

Drug resistance has emerged as a major obstacle to chemotherapy for many infectious diseases. Trifluralin, an antimicrotubule herbicide, is a new experimental drug for treatment of leishmaniasis. Here, we found that it was effective against two strains of Leishmania that express the multidrug-resistant genes ldmdr1 and lmpgpA and two strains that express proteins that are immunologically cross-reactive with mammalian P glycoproteins. These results suggest that trifluralin is not subject to counteractions of these multidrug resistance mechanisms of Leishmania species.