Estudo in vitro da atividade tripanocida de nanopartículas de benzonidazol em carbonato de cálcio sobre cepa y de Trypanosoma cruzi

Abstract

The Chagas disease is a major public health problem, affecting about 6 million people worldwide and causes high morbidity and mortality in affected populations. The benznidazole (BZ), the drug used in the treatment has limited effectiveness and cause serious adverse effects. The drug transport by nanoparticles has demonstrated efficacy as the controlled and targeted release of pharmacological molecules, in addition to its desirable properties such as good biocompatibility and biodegradability. The objective of this study was to evaluate the cytotoxicity of benznidazole nanoparticles of calcium carbonate (CaCO3 @ BZ) on host cells LLC-MK2; determining the trypanocidal effect on epimastigotes, trypomastigote and amastigotes of T. cruzi Y strain and comparing the effect of BZ as well as to characterize the mechanism of death. The cytotoxicity tests using the MTT method conducted with LLC-MK2 cells grown in DMEM with 10% FBS showed IC50 of 55 ug / ml for BZ @ CaCO3 and 160 g / mL for BZ. epimastigotes were cultured in LIT 10% FBS at 28 ° C in the presence of CaCO3 @ BZ for 24, 48 and 72 hours. BZ @ CaCO3 showed trypanocidal activity against epimastigotes the three treatment times (24h IC50 = 8.72 mg / ml, 48 h IC50 = 8 ug / ml, 72 h IC50 = 4.8 ug / ml) this being more significant effect the BZ (IC50 = 24h 56.7 g / ml IC50 = 48h 15.9 g / ml, 72 h IC50 = 4.3 ug / ml). trypomastigotes were obtained from LLC-MK2 cells infected supernatants, resuspended in DMEM with 2% FCS and treated for 24 h. The trypomastigotes were more likely BZ @ CaCO3 (IC50 = 1.8 ug / ml) than the BZ (IC50 = 67 ug / ml). These assays were also performed with calcium carbonate nanoparticles free drug (@ CaCO3) used as negative control. In the tests with the amastigote forms obtained by infecting LLC-MK2 cells BZ @ CaCO3 was able to reduce the% of infected cells, the number of amastigotes per infected cells and the survival rate at 24 hours of incubation. Flow cytometric assays using fluorescence markers 7-amino actinomycin D, annexin V-PE and rhodamine 123 demonstrated that the trypanocidal effect of both BZ @ CaCO3 as BZ associated death by necrosis with altered mitochondrial potential. Thus, it is concluded that the CaCO3 has BZ @ trypanocidal effect in vitro on the three forms of Trypanosoma cruzi, this being potentially greater effect than that observed for BZ.