In vitro effect of curcumin on Schistosoma species viability, tegument ultrastructure and egg hatchability.

Schistosomiasis remains a severe problem of public health in developing countries. The development of resistance to praziquantel (PZQ) has justified the search for new alternative chemotherapies with new formulations, more effective, and without adverse effects. Curcumin (CUR), the major phenolic compound present in rhizome of turmeric (Curcuma longa L.), has been traditionally used against various diseases including parasitic infections. Here, the antischistosomal activity of CUR (50-500 µM), evaluated in parallel against S. mansoni and S. haematobium adult worms, appeared significant (P < 0.05 to < 0.0001) in a time- and dose-dependent manner. Two h incubation with CUR (500 µM) caused 100% irreversible killing of both schistosomal species. CUR (250 µM) caused the death of S. haematobium and S. mansoni worms after 2 h and 4 h, respectively. As CUR concentration decreases (50 µM), all coupled adult worms were separated into individual male and female but the worms remained viable up to 4 h. Scanning and transmission electron microscopy revealed that S. haematobium are more sensitive than S. mansoni to CUR schistosomicidal effects. In support, CUR was found to affect the antigenicity of surface membrane molecules of S. haematobium, but not S. mansoni. Of importance, CUR significantly (P < 0.05 to < 0.0001) affected S. mansoni eggs hatchability and viability, a ground for its use in chemotherapy of schistosomiasis mansoni and japonicum because of its increased bioavailability in the gastrointestinal tract. The data together emphasize that CUR is a promising potential schistosomicidal drug.