Tamoxifen Treatment in Hamsters Induces Protection during Taeniosis byTaenia solium

Abstract

Human neurocysticercosis byTaenia soliumis considered an emergent severe brain disorder in developing and developed countries. Discovery of new antiparasitic drugs has been recently aimed to restrain differentiation and establishment of theT. soliumadult tapeworm, for being considered a central node in the disease propagation to both pigs and humans. Tamoxifen is an antiestrogenic drug with cysticidal action onTaenia crassiceps, a close relative ofT. solium. Thus, we evaluated the effect of tamoxifen on thein vitroevagination and thein vivoestablishment ofT. solium.In vitro, tamoxifen inhibited evagination ofT. soliumcysticerci in a dose-time dependent manner.In vivo, administration of tamoxifen to hamsters decreased the intestinal establishment of the parasite by 70%, while recovered tapeworms showed an 80% reduction in length, appearing as scolices without strobilar development. Since tamoxifen did not show any significant effect on the proliferation of antigen-specific immune cells, intestinal inflammation, and expression of Th1/Th2 cytokines in spleen and duodenum, this drug could exert its antiparasite actions by having direct detrimental effects upon the adult tapeworm. These results demonstrate that tamoxifen exhibits a strong cysticidal and antitaeniasic effect onT. soliumthat should be further explored in humans and livestock.