In vitro action of platinum (II) and platinum (IV) complexes on Trypanosoma cruzi and Leishmania donovani.

The in vitro activities of 22 neutral Pt(II) complexes, 4 Pt(IV) complex salts, and one Pt(II) complex salt on epimastigote forms of Trypanosoma cruzi and promastigote forms of Leishmania donovani were studied. Only 2 out of the 18 complexes with cis-Pt(DDH)Xn structure completely inhibited the growth of the epimastigote forms of T. cruzi and the promastigote of L. donovani. Against T. cruzi the cis-Pt(L)n(Cl)2 complexes showed no activities, but the complex in which the (L) ligand was stilbamidine did show a limited activity against L. donovani. Of the Pt(IV)complex salts, [Pt X6]H2(L) were very active against the epimastigote forms of T. cruzi. However, the Pt(II) complex salt [cis-Pt Cl4]H2 (pentamidine) showed no activity. The actions of the Pt(IV) complex salts on the promastigote forms of L. donovani were different and only those salts in which the (L) ligand was pentamidine or stilbamidine induced parasite growth inhibition. The one Pt(II) salt tested showed no antiparasitic activity. At the same time, the known antiparasitic activities of the nifurtimox and pentamidine molecules were confirmed.