Abstract
Trifluralin, a dinitroaniline microtubule inhibitor currently in use as an herbicide, has been shown to inhibit the proliferation of Plasmodium falciparum, Trypanosoma brucei, and several species of Leishmania, in vitro. As a topical formulation, trifluralin is also effective in vivo (in BALB/c mice) against Leishmania major and Leishmania mexicana. Although trifluralin and other dinitroaniline herbicides show significant activity as antiparasitic compounds, disputed indications of potential carcinogenicity will probably limit advanced development of these substances. However, researchers have suggested that the activity of trifluralin is due to an impurity or contaminant, not to trifluralin itself. We have pursued this lead and identified the structure of the active impurity. This compound, chloralin, is 100 times more active than trifluralin. On the basis of its structure, we developed a rational structure-activity model for chloralin. Using this model, we have successfully predicted and tested active analogs in a Leishmania promastigote assay; thus, we have identified the putative mechanism of action of this class of drugs in Leishmania species. Potentially, this will allow the design of noncarcinogenic, active drugs.
Full Text
The Full Text of this article is available as a PDF (231.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Beck S. L. Additional endpoints and overview of a mouse skeletal variant assay for detecting exposure to teratogens. Teratology. 1993 Feb;47(2):147–157. doi: 10.1002/tera.1420470207. [DOI] [PubMed] [Google Scholar]
- Berman J. D., Chulay J. D., Hendricks L. D., Oster C. N. Susceptibility of clinically sensitive and resistant Leishmania to pentavalent antimony in vitro. Am J Trop Med Hyg. 1982 May;31(3 Pt 1):459–465. doi: 10.4269/ajtmh.1982.31.459. [DOI] [PubMed] [Google Scholar]
- Berman J. D. Structure-function analysis of antimicrotubule dinitroanilines against promastigotes of the parasitic protozoan Leishmania mexicana. Antimicrob Agents Chemother. 1994 Jul;38(7):1692–1693. doi: 10.1128/aac.38.7.1692. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chan M. M., Fong D. Inhibition of leishmanias but not host macrophages by the antitubulin herbicide trifluralin. Science. 1990 Aug 24;249(4971):924–926. doi: 10.1126/science.2392684. [DOI] [PubMed] [Google Scholar]
- Chan M. M., Grogl M., Chen C. C., Bienen E. J., Fong D. Herbicides to curb human parasitic infections: in vitro and in vivo effects of trifluralin on the trypanosomatid protozoans. Proc Natl Acad Sci U S A. 1993 Jun 15;90(12):5657–5661. doi: 10.1073/pnas.90.12.5657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chan M. M., Triemer R. E., Fong D. Effect of the anti-microtubule drug oryzalin on growth and differentiation of the parasitic protozoan Leishmania mexicana. Differentiation. 1991 Feb;46(1):15–21. doi: 10.1111/j.1432-0436.1991.tb00861.x. [DOI] [PubMed] [Google Scholar]
- Chan M. M., Tzeng J., Emge T. J., Ho C. T., Fong D. Structure-function analysis of antimicrotubule dinitroanilines against promastigotes of the parasitic protozoan Leishmania mexicana. Antimicrob Agents Chemother. 1993 Sep;37(9):1909–1913. doi: 10.1128/aac.37.9.1909. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ebert E., Leist K. H., Hack R., Ehling G. Toxicology and hazard potential of trifluralin. Food Chem Toxicol. 1992 Dec;30(12):1031–1044. doi: 10.1016/0278-6915(92)90114-z. [DOI] [PubMed] [Google Scholar]
- Fong D. Effect of the anti-microtubule compound tubulozole on Leishmania protozoan parasites in vitro. FEMS Microbiol Lett. 1993 Feb 15;107(1):95–99. doi: 10.1016/0378-1097(93)90360-e. [DOI] [PubMed] [Google Scholar]
- Francis P. C., Emmerson J. L., Adams E. R., Owen N. V. Oncogenicity study of trifluralin in B6C3F1 mice. Food Chem Toxicol. 1991 Aug;29(8):549–555. doi: 10.1016/0278-6915(91)90047-b. [DOI] [PubMed] [Google Scholar]
- Garriott M. L., Adams E. R., Probst G. S., Emmerson J. L., Oberly T. J., Kindig D. E., Neal S. B., Bewsey B. J., Rexroat M. A. Genotoxicity studies on the preemergence herbicide trifluralin. Mutat Res. 1991 Jun;260(2):187–193. doi: 10.1016/0165-1218(91)90007-9. [DOI] [PubMed] [Google Scholar]
- Grogl M., Thomason T. N., Franke E. D. Drug resistance in leishmaniasis: its implication in systemic chemotherapy of cutaneous and mucocutaneous disease. Am J Trop Med Hyg. 1992 Jul;47(1):117–126. doi: 10.4269/ajtmh.1992.47.117. [DOI] [PubMed] [Google Scholar]
- Hess F. D., Bayer D. E. Binding of the herbicide trifluralin to Chlamydomonas flagellar tubulin. J Cell Sci. 1977 Apr;24:351–360. doi: 10.1242/jcs.24.1.351. [DOI] [PubMed] [Google Scholar]
- Jackson J. E., Tally J. D., Ellis W. Y., Mebrahtu Y. B., Lawyer P. G., Were J. B., Reed S. G., Panisko D. M., Limmer B. L. Quantitative in vitro drug potency and drug susceptibility evaluation of Leishmania ssp. from patients unresponsive to pentavalent antimony therapy. Am J Trop Med Hyg. 1990 Nov;43(5):464–480. doi: 10.4269/ajtmh.1990.43.464. [DOI] [PubMed] [Google Scholar]
- Kaidoh T., Nath J., Fujioka H., Okoye V., Aikawa M. Effect and localization of trifluralin in Plasmodium falciparum gametocytes: an electron microscopic study. J Eukaryot Microbiol. 1995 Jan-Feb;42(1):61–64. doi: 10.1111/j.1550-7408.1995.tb01540.x. [DOI] [PubMed] [Google Scholar]
- Lacey E. Mode of action of benzimidazoles. Parasitol Today. 1990 Apr;6(4):112–115. doi: 10.1016/0169-4758(90)90227-u. [DOI] [PubMed] [Google Scholar]
- Morejohn L. C., Fosket D. E. Inhibition of Plant Microtubule Polymerization in vitro by the Phosphoric Amide Herbicide Amiprophos-Methyl. Science. 1984 May 25;224(4651):874–876. doi: 10.1126/science.224.4651.874. [DOI] [PubMed] [Google Scholar]
- Ouellette M., Papadopoulou B. Mechanisms of drug resistance in Leishmania. Parasitol Today. 1993 May;9(5):150–153. doi: 10.1016/0169-4758(93)90135-3. [DOI] [PubMed] [Google Scholar]
- Sacks D. L., Kenney R. T., Kreutzer R. D., Jaffe C. L., Gupta A. K., Sharma M. C., Sinha S. P., Neva F. A., Saran R. Indian kala-azar caused by Leishmania tropica. Lancet. 1995 Apr 15;345(8955):959–961. doi: 10.1016/s0140-6736(95)90703-3. [DOI] [PubMed] [Google Scholar]
- Thakur C. P., Sinha G. P., Pandey A. K., Barat D., Sinha P. K. Amphotericin B in resistant kala-azar in Bihar. Natl Med J India. 1993 Mar-Apr;6(2):57–60. [PubMed] [Google Scholar]
- Vaughn K. C., Marks M. D., Weeks D. P. A Dinitroaniline-Resistant Mutant of Eleusine indica Exhibits Cross-Resistance and Supersensitivity to Antimicrotubule Herbicides and Drugs. Plant Physiol. 1987 Apr;83(4):956–964. doi: 10.1104/pp.83.4.956. [DOI] [PMC free article] [PubMed] [Google Scholar]
