Curcumin Impact on Ex Vivo Toxocara vitulorum Adult Worms and Eggs

Abstract

Conventional drug treatment expels adult worms from the intestinal tract but does not prevent reinfection and further contamination of the environment with eggs. This study was performed as the start of a program aiming to develop curcumin (CUR) as a lead drug for human and animal ascariasis. Ex vivo adult Toxocara vitulorum and eggs were exposed at 37°C for 4hr to different concentrations of CUR (0-500μM) in Roswell Memorial Park Institute (RPMI) 1640 medium supplemented with 2% dimethyl sulfoxide (DMSO). The results showed that CUR slightly impaired the viability and mobility of approximately 30% of worms in a dose-dependent manner. Scanning electron microscopy revealed changes in cuticles throughout the length of the roundworms exposed to high CUR concentrations. Enzyme-linked immunosorbent assay failed to reveal CUR effects on specific antibody binding to the roundworm surface membrane molecules. To mimic the in vivo situation, after incubation, eggs were washed, suspended in 0.1N sulphuric acids, and examined for development and maturation 4, 7, 11, and 18 days later. Eggs produced from CUR-exposed females showed an even more remarkable delay and impairment in development in comparison to eggs, which were directly exposed to CUR. A significant increase in the number of dead eggs and prevention of maturation to the infective stage were observed in a CUR dose and time-dependent manner. These results encourage investigations of CUR impact on human and animal ascarids of public health and economic importance.