Microtubules as antiparasitic drug targets

Background: Parasitic diseases including malaria, leishmaniasis and schistosomiasis take a terrible toll of human life, health and productivity, especially in tropical and subtropical regions, and are also highly significant in animal health worldwide. Antiparasitic drugs are the mainstays of control of most of these diseases, but in many cases current therapies are inadequate and in some the situation is deteriorating because of drug resistance. Microtubules, as essential components of almost all eukaryotic cells, are proven drug targets in many helminth diseases and show promise as targets for the development of new antiprotozoal drugs. Objective: This article reviews the chemistry of the microtubule inhibitors in current use and under investigation as antiparasitic agents, their activities against the major parasites and their mechanisms of action. New directions in both inhibitor chemistry and biological evaluation are discussed. Conclusions: The most promising immediate avenues for discovery and design appear to lie in development of novel benzimidazoles for helminth parasites and compounds based on antimitotic herbicides for protozoal parasites. New understanding from functional genomics, structural biology and microtubular imaging will help accelerate the development of completely novel antiparasitic drugs targeting microtubules.