Evaluation of the toxicity of Rh(III) and Pt(II) complexes against Trypanosoma cruzi culture forms.

In the present study the activity of 15 complexes of Rh(III) and 19 of Pt(II) against Trypanosoma cruzi epimastigote forms was investigated. The results obtained show that complexes of Rh(III) with the highest antitumoural activity also appear to be more effective against cultured epimastigotes. Thus, complexes [Rh(L)4X2]+X- where L is a derivative of thiazole present high activity against the parasite, and were even more active when Cl- (X) was present in their structure. Complexes cis-Pt(L)m(X)n that present 1,2-diamminecyclohexane (DDH) in their molecule, e.g. cis-Pt(DDH)Cl2 and cis-Pt(DDH)(metafluorobenzoic)2 of high and moderate antitumoural activity, respectively, have shown greater effectiveness than cis-Pt(NH3)2Cl2 (DDP). The effect produced by cis-Pt(pentamidine)Cl2 complex, obtained in order to enforce the action of pentamidine, was considerably high. On the other hand, no positive correlation can be established between the antitumour effects of the Pt(II) complexes and its antitrypanosomic activity.