Schistosoma mansoni: Schistosomicidal effect of mefloquine and primaquine in vitro

We investigated the effects of the anti-malarials mefloquine and primaquine against the juvenile and adult life stages of Schistosoma mansoni in vitro. Cercariae were incubated with 0.5 mu/ml, 1 mu/ml and 2 mu g/ml mefloquine or primaquine and with 1 mu/ml praziquantel for 12 h. Schistosomula, pre-adults and adults were incubated with 0.5 mu g/ml, 1 mu g/ml and 2 mu g/ml mefloquine or primaquine and with 1 mu g/ml praziquantel for 7 days. The viability status was classified as viable, damaged or dead and was checked every 3 h for cercariae and every 12 h for schistosomula, pre-adults and adults. Both, mefloquine and primaquine show time and dose-dependent schistosomicidal effects on the four life stages of S. mansoni. The promising in vitro effects on all stages of the blood fluke S. mansoni warrants further evaluation of both anti-malarials and their derivatives for their prophylactic and therapeutic values in early and late schistosomiasis in field trials. (C) 2010 Elsevier Inc. All rights reserved.