Buthionine sulfoximine is a multitarget inhibitor of trypanothione synthesis in Trypanosoma cruzi.

Buthionine sulfoximine (BSO) induces decreased glutathione (GSH) and trypanothione [T(SH) ] pools in trypanosomatids, presumably because only gamma-glutamylcysteine synthetase (γECS) is blocked. However, some BSO effects cannot be explained by exclusive γECS inhibition; therefore, its effect on the T(SH) metabolism pathway in Trypanosoma cruzi was re-examined. Parasites exposed to BSO did not synthesize T(SH) even when supplemented with cysteine or GSH, suggesting trypanothione synthetase (TryS) inhibition by BSO.