title: Blood schizontocidal activity of methylene blue in combination with antimalarials against Plasmodium falciparum.
abstract: Methylene blue (MB) is the oldest synthetic antimalarial. It is not used anymore as antimalarial but should be reconsidered. For this purpose we have measured its impact on both chloroquine sensitive and resistant Plasmodium strains. We showed that around 5 nM of MB were able to inhibit 50% of the parasite growth in vitro and that late rings and early trophozoites were the most sensitive stages; while early rings, late trophozoites and schizonts were less sensitive. Drug interaction study following fractional inhibitory concentrations (FIC) method showed antagonism with amodiaquine, atovaquone, doxycycline, pyrimethamine; additivity with artemether, chloroquine, mefloquine, primaquine and synergy with quinine. These results confirmed the interest of MB that could be integrated in a new low cost antimalarial combination therapy.
authors.affiliation: Departamento de Farmacia, Facultad de Ciencias, Universitad Nacional de Colombia, Carrera 30 45-03 Bogotá D C, Colombia.
authors.forename: G
authors.initials: G
authors.lastname: Garavito
authors.forename: S
authors.initials: S
authors.lastname: Bertani
authors.forename: J
authors.initials: J
authors.lastname: Rincon
authors.forename: S
authors.initials: S
authors.lastname: Maurel
authors.forename: M C
authors.initials: MC
authors.lastname: Monje
authors.forename: I
authors.initials: I
authors.lastname: Landau
authors.forename: A
authors.initials: A
authors.lastname: Valentin
authors.forename: E
authors.initials: E
authors.lastname: Deharo
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D006801:Humans; D020128:Inhibitory Concentration 50; D016778:Malaria, Falciparum / Q000188:drug therapy*; D008751:Methylene Blue / Q000494:pharmacology* / Q000627:therapeutic use; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D008751:Methylene Blue