title: Trypanosoma cruzi: insights into naphthoquinone effects on growth and proteinase activity.
abstract: In this study we compared the effects of naphthoquinones (α-lapachone, β-lapachone, nor-β-lapachone and Epoxy-α-lap) on growth of Trypanosoma cruzi epimastigotes forms, and on viability of VERO cells. In addition we also experimentally analyzed the most active compounds inhibitory profile against T. cruzi serine- and cysteine-proteinases activity and theoretically evaluated them against cruzain, the major T. cruzi cysteine proteinase by using a molecular docking approach. Our results confirmed β-lapachone and Epoxy-α-lap with a high trypanocidal activity in contrast to α-lapachone and nor-β-lapachone whereas Epoxy-α-lap presented the safest toxicity profile against VERO cells. Interestingly the evaluation of the active compounds effects against T. cruzi cysteine- and serine-proteinases activities revealed different targets for these molecules. β-Lapachone is able to inhibit the cysteine-proteinase activity of T. cruzi proteic whole extract and of cruzain, similar to E-64, a classical cysteine-proteinase inhibitor. Differently, Epoxy-α-lap inhibited the T. cruzi serine-proteinase activity, similar to PMSF, a classical serine-proteinase inhibitor. In agreement to these biological profiles in the enzymatic assays, our theoretical analysis showed that E-64 and β-lapachone interact with the cruzain specific S2 pocket and active site whereas Epoxy-α-lap showed no important interactions. Overall, our results infer that β-lapachone and Epoxy-α-lap compounds may inhibit T. cruzi epimastigotes growth by affecting T. cruzi different proteinases. Thus the present data shows the potential of these compounds as prototype of protease inhibitors on drug design studies for developing new antichagasic compounds.
authors.affiliation: Universidade Federal Fluminense, Instituto de Biologia, 24020-150 Niterói, RJ, Brazil.
authors.forename: Saulo C
authors.initials: SC
authors.lastname: Bourguignon
authors.forename: Danielle F B
authors.initials: DF
authors.lastname: Cavalcanti
authors.forename: Alessandra M T
authors.initials: AM
authors.lastname: de Souza
authors.forename: Helena C
authors.initials: HC
authors.lastname: Castro
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Rodrigues
authors.forename: Magaly G
authors.initials: MG
authors.lastname: Albuquerque
authors.forename: Dilvani O
authors.initials: DO
authors.lastname: Santos
authors.forename: Gabriel Gomes
authors.initials: GG
authors.lastname: da Silva
authors.forename: Fernando C
authors.initials: FC
authors.lastname: da Silva
authors.forename: Vitor F
authors.initials: VF
authors.lastname: Ferreira
authors.forename: Rosa T
authors.initials: RT
authors.lastname: de Pinho
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Alves
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D003546:Cysteine Endopeptidases; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D009285:Naphthoquinones / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000187:drug effects* / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D014709:Vero Cells
chemical_list: C540757:2,2-dimethyl-3,4-dihydrospiro(benzo(g)chromene-10,2'-oxiran)-5(2H)-one; D000890:Anti-Infective Agents; D015853:Cysteine Proteinase Inhibitors; D009285:Naphthoquinones; D011480:Protease Inhibitors; D015800:Protozoan Proteins; C014638:beta-lapachone; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; C074032:cruzain, Trypanosoma cruzi; D007930:Leucine; C024974:E 64; C415043:alpha-lapachone