title: Effects and mode of action of 1,4-naphthoquinones isolated from Calceolaria sessilis on tumoral cells and Trypanosoma parasites.
abstract: The naphthoquinones 2-hydroxy-3-(1,1-dimethylallyl)-1,4-naphthoquinone (CS-1), (-)-2,3,3-trimethyl-2-3-dihydronaphtho[2,3-b]furan-4,9-quinone (CS-3), and 2-acetoxy-3-(1,1-dimethylallyl)-1,4-naphthoquinone (CS-5) isolated from Calceolaria sessilis were tested against Trypanosoma cruzi epimastigotes, the TA3 tumor cell line and the methotrexate-resistant subline TA3-MTX-R. Naphthoquinone CS-3 was the most active; the 50% culture growth inhibition (I50) on T. cruzi (Tulahuén and LQ strain and DM28c clone) was at concentrations ranging from 2.1 to 5.2 mumolar. Also CS-3 inhibited TA3 and TA3-MTX-R culture growth with an I50 of 2.1 and 3.8 mumolar, respectively. Naphthoquinone CS-3 inhibited the respiration of the tumor cells by interfering with the electron transport at some point between NADH and ubiquinone. The respiration of T. cruzi was not inhibited by naphthoquinone CS-3. Naphthoquinone CS-3 produced a temporary increase of oxygen consumption in T. cruzi and tumor cells, suggesting the generation and participation of free radicals.
authors.affiliation: Department of Biochemistry, University of Chile Santiago.
authors.forename: A
authors.initials: A
authors.lastname: Morello
authors.forename: M
authors.initials: M
authors.lastname: Pavani
authors.forename: J A
authors.initials: JA
authors.lastname: Garbarino
authors.forename: M C
authors.initials: MC
authors.lastname: Chamy
authors.forename: C
authors.initials: C
authors.lastname: Frey
authors.forename: J
authors.initials: J
authors.lastname: Mancilla
authors.forename: A
authors.initials: A
authors.lastname: Guerrero
authors.forename: Y
authors.initials: Y
authors.lastname: Repetto
authors.forename: J
authors.initials: J
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D019069:Cell Respiration / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D008297:Male; D051379:Mice; D009285:Naphthoquinones / Q000302:isolation & purification / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D010946:Plants, Medicinal / Q000737:chemistry*; D016897:Respiratory Burst / Q000187:drug effects; D014344:Trypanocidal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D009285:Naphthoquinones; D014344:Trypanocidal Agents