Stage-specific activity of potential antimalarial compounds measured in vitro by flow cytometry in comparison to optical microscopy and hypoxanthine uptake.
The evaluation of new antimalarial agents using older methods of monitoring sensitivity to antimalarial drugs are laborious and poorly suited to discriminate stage-specific activity. We used flow cytometry to study the effect of established antimalarial compounds, cysteine protease inhibitors, and a quinolone against asexual stages of Plasmodium falciparum. Cultured P. falciparum parasites were treated for 48 h with different drug concentrations and the parasitemia was determined by flow cytometry methods after DNA staining with propidium iodide. P. falciparum erythrocytic life cycle stages were readily distinguished by flow cytometry. Activities of established and new antimalarial compounds measured by flow cytometry were equivalent to results obtained with microscopy and metabolite uptake assays. The antimalarial activity of all compounds was higher against P. falciparum trophozoite stages. Advantages of flow cytometry analysis over traditional assays included higher throughput for data collection, insight into the stage-specificity of antimalarial activity avoiding use of radioactive isotopes.
Contreras
Carmen E
CE
Instituto de Inmunología, Facultad de Medicina, Universidad Central, Apartado Postal 50109, Caracas 1050 A, Venezuela. contrerc@camelot.rect.ucv.ve
Rivas
María A
MA
Domínguez
José
J
Charris
Jaime
J
Palacios
Mario
M
Bianco
Nicolás E
NE
Blanca
Isaac
I
D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical; D005434:Flow Cytometry; D019271:Hypoxanthine / Q000378:metabolism*; D007928:Lethal Dose 50; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D015363:Quinolones / Q000494:pharmacology*
D000962:Antimalarials; D015853:Cysteine Proteinase Inhibitors; D015363:Quinolones; D019271:Hypoxanthine