The current pharmacological Chagas disease treatments, using Nifurtimox or Benznidazole, show limited therapeutic results and are associated with potential side effects, like mutagenicity. Using random screening we have identified new chemotypes that were able to inhibit relevant targets of the Trypanosoma cruzi. We found 3H-[1,2]dithioles with the ability to inhibit Trypanosoma cruzi triosephosphate isomerase (TcTIM). Herein, we studied the structural modifications of this chemotype to analyze the influence of volume, lipophilicity and electronic properties in the anti-T. cruzi activity. Their selectivity to parasites vs. mammalian cells was also examined. To get insights into a possible mechanism of action, the inhibition of the enzymatic activity of TcTIM and cruzipain, using the isolated enzymes, and the inhibition of membrane sterol biosynthesis and excreted metabolites, using the whole parasite, were achieved. We found that this structural framework is interesting for the generation of innovative drugs for the treatment of Chagas disease.

2-Amino-7-fluorophenazine 5,10-dioxide (FNZ) is a bioreducible prodrug, poorly soluble in water, with potential anticancer activity on hypoxic-tumors. This poor solubility limits its potential applications in clinic. Amphiphilic pristine polymeric micelles (PMs) based on triblock copolymers Pluronic^® and Tetronic^®, glycosylated derivatives and their mixtures with preformed-liposomes (LPS), were analyzed as strategies to improve the bioavailability of FNZ. FNZ encapsulations were performed and the obtaining nanostructures were characterized using UV-visible spectroscopy (UV-VIS), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The most promising nanoformulations were analyzed for their potential toxicity and pharmacologically, at 20 mg/kg FNZ-doses, in a stage-IV murine metastatic-breast tumor model. The results revealed that the solubility of the encapsulated-FNZ increased up to 14 times and the analysis (UV-VIS, DLS and TEM) confirmed the interaction between vehicles and FNZ. In all the cases appropriate encapsulation efficiencies (greater than 75%), monodisperse nanometric particle sizes (PDI = 0.180–0.335), adequate Z-potentials (−1.59 to −26.4 mV), stabilities and spherical morphologies were obtained. The in vitro profile of FNZ controlled releases corresponded mainly to a kinetic Higuchi model. The in vitro/in vivo biological studies revealed non-toxicity and relevant tumor-weight diminution (up to 61%).

Chagas disease is caused by the protozoan Trypanosoma cruzi (T. cruzi). It remains the major parasitic disease in Latin America and is spreading worldwide, affecting over 10 million people. Hundreds of new compounds with trypanosomicidal action have been identified from different sources such as synthetic or natural molecules, but they have been deficient in several stages of drug development (toxicology, scaling-up, and pharmacokinetics). Previously, we described a series of compounds with simple structures, low cost, and environmentally friendly production with potent trypanosomicidal activity in vitro and in vivo. These molecules are from three different families: thiazolidenehydrazines, diarylideneketones, and steroids. From this collection, we explored their capacity to inhibit the triosephosphate isomerase and cruzipain of T. cruzi. Then, the mechanism of action was explored using NMR metabolomics and computational molecular dynamics. Moreover, the mechanism of death was studied by flow cytometry. Consequently, five compounds, 314, 793, 1018, 1019, and 1260, were pre-clinically studied and their pharmacologic profiles indicated low unspecific toxicity. Interestingly, synergetic effects of diarylideneketones 793 plus 1018 and 793 plus 1019 were evidenced in vitro and in vivo. In vivo, the combination of compounds 793 plus 1018 induced a reduction of more than 90% of the peak of parasitemia in the acute murine model of Chagas disease.

Breast cancer is a solid tumor characterized by a high level of hypoxic areas which are difficult to treat. The rate of this disease in women is elevated, mainly in developing countries since the diagnosis is made in the later stages of the disease. We have developed bioreductive prodrugs under conditions of hypoxia in which the compound 2-amino-7(8)-fluorophenazine N 5 ,N 10 - dioxide (FNZ) stands out as a potent and selective anticancer agent. In order to improve the ADME properties the FNZ was vehiculated in physiological serum:tween (PS:T). This work presents the optimization of the synthesis of FNZ, the evaluation of the mutagenic potential in vitro (AMES test) and the acute toxicity (Up & Down) of free-FNZ and its encapsulated. The optimization of the procedure to scale-up 5 g was done according to the synthesis already described. Washing and drying conditions of the benzofuroxan intermediate and FNZ allowed an overall yield of 60 %, five times higher than the micro-scale procedure. We performed the Ames assay on five strains of Salmonella typhimurium (TA98, TA100, TA1535, TA1537, TA102) recommended for drug development. The preliminary results indicate that all the systems under study (Free-FNZ, PS:T/FNZ) exhibited mutagenicity in the five Salmonella strains. The most mutagenic system was the free-FNZ being the encapsulation using (PS:T) the least. The acute toxicity showed that the vehiculated FNZ had a maximum dose of 2000 mg/kg of mouse weight. The vehiculated FNZ was not toxic in the Up & Down assay transforming it in a good formulation to be used in vivo studies. Acknowledgement: The authors want to thank the ANII for financial support.