Application of non-fluorescent dyes to assess the antischistosomal effect of antimalarial drugs on  Schistosoma mansoni  adult worms

Abstract

The possible emergence of praziquantel (PZQ)-tolerant and/or resistant schistosomes urgently necessitates the study and development of new antischistosomal drugs as alternatives to PZQ. The aim of the present study was to investigate the capacity of three dyes, namely methylene blue (MB), neutral red (NR) and trypan blue (TB), for the assessment of the in vitro antischistosomal effect of antimalarial drugs on Schistosoma mansoni adult worms. S. mansoni adult worms were incubated in a medium alone for control or supplemented with 10 μg/ml primaquine (PQ), artesunate (AR) and amodiaquine (AQ) for five days. Subsequently, their viabilities were observed, and the worms were stained with MB, NR and TB, respectively. The disparity of MB and NR staining status among male and female adult worms treated with PQ, AR and AQ with correlated with the various levels of damage to the male and female worms. Furthermore, the severity of the damage to the adult worms treated with the three drugs might be reflected in the TB staining status. The present study shows that these non-fluorescent dyes can serve as a useful complementary tool for assessing the antischistosomal effect of antimalarial drugs.