Crystal violet structural analogues identified by in silico drug repositioning present anti-Trypanosoma cruzi activity through inhibition of proline transporter TcAAAP069

Abstract

Background Crystal violet (CV) was used for several years in blood banks to eliminate the parasite Trypanosoma cruzi in endemic areas in order to prevent transfusion-transmitted Chagas disease. One mechanism of action described for CV involves inhibition of proline uptake. In T. cruzi, proline is essential for host cell infection and intracellular differentiation among other processes, and can be obtained through the proline permease TcAAAP069. Methodology/Principal findings CV inhibited proline transporter TcAAAP069 and parasites overexpressing this permease were 47-fold more sensitive to this compound than control parasites. Using CV as reference molecule, loratadine, cyproheptadine, olanzapine and clofazimine were identified as structurally related compounds to CV (structural analogues) by in silico drug repurposing through a similarity-based virtual screening protocol. All these already-approved drugs for clinical use inhibited TcAAAP069 activity with different efficacies and also presented trypanocidal action in epimastigotes, trypomastigotes and amastigotes of the Y, CL Brener and Dm28c T. cruzi strains. Finally, a synergistic effect between benznidazole and the CV chemical analogues was evidenced by combination and dose-reduction indexes values in epimastigotes and trypomastigotes of the Y strain. Conclusions/Significance Loratadine, cyproheptadine and clofazimine inhibit TcAAAP069 proline transporter and also present trypanocidal effect against all T. cruzi life stages in strains from three different DTUs. These CV structural analogues could be a starting point to design therapeutic alternatives to treat Chagas disease by finding new indications for old drugs. This approach,

Metabolite Biomarkers of Leishmania Antimony Resistance

“…Notably, proline analogues have been explored as promising therapeutic alternatives in trypanosomes [ 59 ]. In Leishmania parasites, ω-amino acid 4-amino-butiric (GABA), a proline analogue, inhibits the proline/alanine transporter and causes toxicity in both promastigotes and amastigotes [ 60 ].…”

Targeting L-Proline Uptake as New Strategy for Anti-chagas Drug Development

“…The proline uptake has been explored as target for Chagas disease by drug repurposing. Using that approach, crystal violet has been identified as an interesting candidate (Sayé et al, 2020).…”

“…The proline uptake has been explored as target for Chagas disease by drug repurposing. Using that approach, crystal violet has been identified as an interesting candidate (Sayé et al, 2020 ). Our approach is the first report of new compounds that have been design, prepared and validated as proline uptake blockers with antiparasitic activity.…”

Computational approaches for drug discovery against trypanosomatid-caused diseases

“…Using crystal violet as a query for a drug repurposing ligand-based VS, loratadine, cyproheptadine, olanzapine and clofazimine were identified as structurally related compounds. All these already-approved drugs for clinical use inhibited TcAAAP069 activity with different efficacies, presented trypanocidal action in epimastigotes, trypomastigotes and amastigotes of different T. cruzi strains and also presented a synergistic effect in combination with benznidazole (Saye et al, 2020) Regarding the above-mentioned examples, some properties of membrane transporters as targets for drug development are outlined in Fig. 3B.…”