Prospects of halofuginone as an antiprotozoal drug scaffold

Halofuginone is a clinically active derivative of febrifugine that was first isolated from the Chinese herb Dichroa febrifuga. The beneficial biological effects of halofuginone on various diseases including parasitic diseases, cancer, fibrosis, and autoimmune disorders have been investigated. Halofuginone has reduced toxic side effects when compared to febrifugine, an advantage that has led to the commercial availability of halofuginone-based antiparasitic drugs for animal use, and to human clinical trials for the treatment of tumors and fibrosis. This review summarizes advances in determining the mechanism of action of halofuginone, focusing on its antiparasitic role in malaria, cryptosporidiosis, coccidiosis, toxoplasmosis, and leishmaniasis. We discuss mechanistic insights into halofuginone's primary mode of action which involves inhibition of the prolyl-tRNA synthetase enzyme, which is crucial in protein synthesis. Halofuginone exemplifies the untapped wealth of plant-derived compounds in disease therapeutics.