Potential effect of Curcuma longa extract on infectivity and pathogenicity of Schistosoma mansoni cercariae

Batch of freshly shed cercariae from infected laboratory bred Biomphalaria alexandrina were exposed to different sub-lethal concentrations of turmeric extract for an hour and divided into two groups. The first one was to study the ultrastructural changes induced in them using scanning electron microscopy (SEM). The second group was to study infectivity and pathogenicity of the exposed cercariae. One hundred and fifty mice were divided into 5 groups: GI: Infected by normal cercariae and served as controls; GII, GIII, GIV & GV infected by cercariae exposed to 2.5, 5, 7.5 & 10 ppm, respectively. Ten weeks post infection all animals were sacrificed and subjected to parasitologic, histopathologic and immunologic assays. SEM showed cercariae exposed to 5 ppm with minimal destruction of head spines and tail. The degenerative changes were progressively severe by increasing extract concentration to reach complete destruction of both at 10 ppm. Infectivity decreased with the increase in concentration to reach highest significance at 10 ppm. Pathogenicity or mean number of egg deposited, mean diameter of liver granulomas and level of IL-10 gene expression significantly decreased in Gs IV & V.