Avaliação da eficácia e segurança de produtos naturais e sintéticos ativos sobre o Trypanosoma cruzi

Abstract

More than 110 years after the discovery of Chagas Disease (CD), only two nitro-heterocyclic derivatives, associated with partial efficacy and adverse effects, are available for the treatment of approximately 7 million infected people, mainly in Latin America. Considering the importance of bioprospection and rational drug design in the search for more selective therapeutic alternatives, this work investigated, using in silico and in vitro methods, the efficacy and safety of natural and synthetic products with potential application in the control of the parasitic infection by Trypanosoma cruzi. The natural products consisted of a hydromethanolic extract of the leaves of Plinia cauliflora (HME), known as jabuticabeira, and its most abundant phenolic constituents, and the synthetic ones were two new 3-nitro-1,2,4-triazole derivatives, PCBN 009/17 and PCBN 012/17. The metabolomic characterization of the extract was performed by ultra-efficiency liquid chromatography coupled with mass spectrometry. Preliminary in silico analyzes of pharmacokinetic and toxicity (ADMET) properties were conducted on the LAZAR, pkCSM and SwissADME platforms. Subsequently, mutagenicity and genotoxicity were investigated by Ames test and micronucleus assay, in parallel with the determination of cytotoxicity in HepG2 and F C3H liver cells by WST-1 and LDH assays. The in vitro trypanocidal activity was evaluated on trypomastigote forms of the Y strain of T. cruzi. A total of 14 phenolic compounds were identified in HME, mostly flavonoids. In silico predictions for the most abundant compounds, (+)-catechin, digallic acid, and hesperidin, indicated a moderately viable druglikeness profile with low toxicity. In in vitro assays, HME did not produce point mutations in the prokaryotic model, nor an increase in the frequency of micronuclei. However, it exhibited cytostatic effects, reducing nuclear division rates of HepG2. In addition, HME showed time- and dose-dependent cytotoxicity in both strains, promoting cell death through cell membrane damage and more evidently through mitochondrial dysfunction, with F C3H being the most sensitive line. At low concentrations, HME inhibited blood trypomastigotes, generating dose-dependent responses after 2 and 24 hours of exposure. In silico analyzes of the nitrotriazole derivatives indicated structural toxicity alerts for both molecules, which were predicted as hepatotoxic and as substrates of CYP450 enzymes related to drug-drug interactions. Furthermore, the derivatives were predicted to be mutagenic, in agreement with in vitro results, in which they induced base-pair substitution and frameshift mutations. However, the mutagenicity and function of metabolic activation were influenced by the type of substituent, since PCBN 012/17 was mutagenic only at the highest concentration evaluated. The derivatives mainly induced cytotoxicity associated with cell membrane damage, at concentrations higher than their previously described trypanocidal concentrations. In summary, despite the occasional evidence of toxicity, the natural and synthetic products evaluated in this study, especially PCBN 012/17, can be used in the development of more accessible and selective therapeutic alternatives for CD