Metabolism of benznidazole in hepatic microsomes from 3 different mammalian species

ROCCO, DM; GULIN, JEN; GARCÍA BOURNISSEN, F

Buenos Aires

Otro; 1° Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedad Argentina de Investigación Clínica

Chagas disease constitutes a major public health problem in Latin America and there are more 7 million infected people in the. Benznidazole is an antiparasitic drug with proven efficacy reason why is chosen as first-line treatment, but there is few information about benznidazole pharmacokinetics, particularly its metabolism. The knowledge about biotransformation pathway of this drug is critical to understanding side effects and predicting potential drug-drug and drug-disease interactions. This work describes a study to analyze a possible metabolism pathway of benznidazole using hepatic microsomes that contains cytochrome P450 (CYPs) enzymes involved in phase I metabolism. Hepatic microsomes were isolated from 3 different species: Pig, Mouse and Rat. After microsomal purification, protein was determined by Bradford technique and activity of two CYPs (CYP1E2, CYP3A4) was detected reading hydroxylation of p-nitrophenol. Experiments were made incubating microsomal protein with necessary cofactors and benznidazole in a final concentration of 10 μg/ml. Reactions were initiated by adding NADPH and were incubated 60 minutes at 37ºC. After incubation and samples processing it was measure concentration of benznidazole with UHPLC. Data were analyzed by multiple linear regression using R. A decrease of benznidazole concentration comparing to controls (i.e. microsomes with benznidazole and without NADPH) was observed in the three species (highest in Rat). These results suggests that biotransformation could be mediated by CYPs as a phase I reaction. Next step is to identify metabolites with mass spectrometry and which isoforms of CYPs were involved in benznidazole metabolism.