title: Evaluation of methylene blue, pyrimethamine and its combination on an in vitro Neospora caninum model.
abstract: Neospora caninum is an apicomplexan parasite strongly related to reproductive problems in cattle. The neosporosis control is not well established and several fronts are under development, predominantly based on immune protection, immunomodulation and chemotherapy. The use of anti-malarial drugs as therapeutic sources has, in theory, considerable potential for any apicomplexan. Drugs such as methylene blue (MB) and pyrimethamine (Pyr) represent therapeutic options for malaria; thus, their use for neosporosis should be assessed. In this work, we tested the effects of MB and Pyr on N. caninum proliferation and clearance, using LacZ-tagged tachyzoites. The drugs inhibited at nanomolar dosages and its combination demonstrated an antagonistic interaction in proliferation assays, according to the Chou and Talalay method for drug combination index. However, the drug combination significantly improved the parasite in vitro clearance. The repositioning of well-established drugs opens a short-term strategy to obtain low-cost therapeutics approaches against neosporosis.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto,Universidade de São Paulo,Av do Café,s/n,14040-903,Ribeirão Preto,SP,Brazil.
authors.forename: Luiz Miguel
authors.initials: LM
authors.lastname: Pereira
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto,Universidade de São Paulo,Av do Café,s/n,14040-903,Ribeirão Preto,SP,Brazil.
authors.forename: Isabel Cristina
authors.initials: IC
authors.lastname: Vigato-Ferreira
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto,Universidade de São Paulo,Av do Café,s/n,14040-903,Ribeirão Preto,SP,Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: DE Luca
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto,Universidade de São Paulo,Av do Café,s/n,14040-903,Ribeirão Preto,SP,Brazil.
authors.forename: Cássia Mariana
authors.initials: CM
authors.lastname: Bronzon DA Costa
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto,Universidade de São Paulo,Av do Café,s/n,14040-903,Ribeirão Preto,SP,Brazil.
authors.forename: Ana Patrícia
authors.initials: AP
authors.lastname: Yatsuda
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D002522:Chlorocebus aethiops; D003048:Coccidiosis / Q000188:drug therapy*; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D020128:Inhibitory Concentration 50; D008751:Methylene Blue / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D018688:Neospora / Q000187:drug effects*; D011739:Pyrimethamine / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D014709:Vero Cells / Q000187:drug effects
chemical_list: D000962:Antimalarials; D004791:Enzyme Inhibitors; D008751:Methylene Blue; D011739:Pyrimethamine
keywords: 
                 Neospora caninum
              ; drug combination; methylene blue; pyrimethamine; repositioning