Avaliação do efeito leishmanicida e imunomodulador da furazolidona e seus produtos da complexação com ciclodextrinas sobre a infecção por Leishmania (l.) Infantum

Abstract

Visceral leishmaniasis (VL) is a systemic disease caused by protozoa of the genus Leishmania and transmitted by sandflies. Early diagnosis and treatment remain the main mechanisms of VL control, however, the available pharmacotherapy is still limited and the search for new treatments for VL remains a worldwide medical emergency. Thus, the objective of this work is to evaluate in vitro the cytotoxic, leishmanicidal and immunomodulatory activity in macrophages (M1 and M2) of furazolidone (FZD) and its complexation products with cyclodextrin (FZD-CD) at different concentration ratios on the Leishmania (L.) infantum infection. Initially, a systematic review was carried out, following the PICO strategy (Problem, Intervention, Comparison and Outcome), in order to establish which immune mechanisms are described on the effects of FZD administration. Then, in vitro activity assays were performed: cytotoxicity test (J774 murine macrophage lineage cells), 50% growth inhibition of promastigote forms (IC50), 50% growth inhibition of amastigote forms (ICA50) of Leishmania (L.) infantum, selectivity index estimation, phagocytosis analysis by zymosan count, dosage of reactive oxygen species and nitric oxide, in addition to the immunophenotyping of M1 and M2 macrophages. As a result of the systematic review, 943 papers were found, 605 were selected after removal of duplication, 35 remained for eligibility and of these, 4 answered the guiding question and were included. The studies included indicated that the administration of FZD can induce pro- or anti-inflammatory pathways, with the likely increase in the expression of reactive oxygen species and modulation of apoptotic pathways. Experimental tests revealed that of the 12 complexation products, the physical mixture of FZD with β-cyclodextrin in the proportion 1:2 and the physical mixture of FZD with hydroxypropyl-β-cyclodextrin in the proportion 1:1 had leishmanicidal effects in the promastigote and amastigote forms and with lower cytotoxicity (Selectivity Index [IS] values of 13.8 and 499.37 µg/mL, respectively; considering leishmanicidal data against amastigotes) when compared to furazolidone (IS value of 2.52 µg/mL). Only free FZD at a concentration of 0.3 µg/mL increased the rate of phagocytosis and at a concentration of 3 µg/mL it stimulated NO production. The physical mixture of FZD with hydroxypropyl-β-cyclodextrin in a 1:1 ratio induced the formation of reactive oxygen species at a concentration of 3 µg/mL. Finally, FZD and MFHFZD 1:1 did not show a significant increase in the percentage of macrophages polarized in M1 and M2, and our hypothesis was partially tested, where the complexation of furazolidone with cyclodextrins originated non-complex complexes and aggregates with leishmanicidal effect, with low toxicity, stimulating phagocytosis and production of reactive oxygen and nitric oxide species, but not leading to macrophage polarization in the M1 profile in an in vitro model of infection by Leishmania (L.) infantum.