Molecular mechanisms and therapeutic approaches to the treatment of African trypanosomiasis.

There are only a handful of drugs available today for treating African trypanosomiasis, most of which were discovered more than forty years ago. These drugs are plagued by various problems, ranging from oral in-absorption, acute toxicities, short durations of action, and low efficacies to the emergence of trypanosomal resistance. Mechanisms of antitrypanosomal action of these drugs are mostly unknown, except for eflornithine, which is a suicide inhibitor of ornithine decarboxylase. On the other hand, the African trypanosomes are among the most extensively studied parasitic protozoa to date. Many of their intriguing biological features have been well documented and can be viewed as attractive targets for antitrypanosomal chemotherapy. These features include the glycosomal functions and protein import, the trans-splicing of mRNAs, the machineries for controlled protein degradations, the polyamine metabolism, the trypanothione metabolism, the purine salvage enzymes, and the glycolipid anchor for the surface glycoproteins.