Study of the antimalarial properties of hydroxyethylamine derivatives using green fluorescent protein transformed Plasmodium berghei

A rapid decrease in parasitaemia remains the major goal for new antimalarial drugsand thus, in vivo models must provide precise results concerning parasitaemiamodulation. Hydroxyethylamine comprise an important group of alkanolamine compoundsthat exhibit pharmacological properties as proteases inhibitors that has already beenproposed as a new class of antimalarial drugs. Herein, it was tested the antimalarialproperty of new nine different hydroxyethylamine derivatives using the greenfluorescent protein (GFP)-expressing Plasmodium berghei strain. Bycomparing flow cytometry and microscopic analysis to evaluate parasitaemiarecrudescence, it was observed that flow cytometry was a more sensitive methodology.The nine hydroxyethylamine derivatives were obtained by inserting one of thefollowing radical in the para position: H, 4Cl, 4-Br, 4-F, 4-CH3,4-OCH3, 4-NO2, 4-NH2 and 3-Br. The antimalarial test showed that the compound thatreceived the methyl group (4-CH3) inhibited 70% of parasite growth. Our resultssuggest that GFP-transfected P. berghei is a useful tool to study the recrudescenceof novel antimalarial drugs through parasitaemia examination by flow cytometry.Furthermore, it was demonstrated that the insertion of a methyl group at thepara position of the sulfonamide ring appears to be critical forthe antimalarial activity of this class of compounds.