Tamoxifen might be effective in the treatment of Leishmania amazonensis infections

June 11, 2008

Researchers from the University of São Paulo, Brazil, have shown the efficacy of an alternative drug against Leishmania amazonensis, one of the species that causes cutaneous leishmaniasis in South America. Details, published June 11th in the open-access journal PLoS Neglected Tropical Diseases, explain how tamoxifen – a medication widely used in the treatment and prevention of breast cancer – fights the parasitic disease in experimentally infected mice.

Unicellular parasites of Leishmania genus are the causative agents of leishmaniasis. Treatment of leishmaniasis requires the administration of toxic and poorly tolerated drugs. Having previously demonstrated that tamoxifen was active against parasites in vitro, the authors now show its efficacy in a rodent model of infection with L. amazonensis.

The Brazilian group, led by Silvia Uliana, observed that infected mice treated with 20 mg/kg/day of tamoxifen for 2 weeks showed a significant reduction in parasite burden. Researchers also detected a notable delay in the development of skin ulcers, a typical symptom of the disease caused by L. amazonensis.

The promising results presented in this study, coupled with the fact that tamoxifen's safety and pharmacological profiles in humans are well established, point to a new alternative in the treatment of leishmaniasis. Further trials will be necessary in other experimental models of infection before the drug is tested in humans.

Reference: http://www.plosntds.org/doi/pntd.0000249

Source: Public Library of Science