Effects of Solanum nigrum leaves water extract on the penetration and infectivity of Schistosoma mansoni cercariae.

A crude water extract of Solanum nigrum leaves was used as a chemical attenuate to Schistosoma mansoni cercariae prior to infection of Swiss female mice. Cercariae were exposed to 2.5, 5, 7.5 and 10 mg/l concentrations of the extract for 30 min. The effect on the ability of cercariae to penetrate mice skin, as well as, effect on schistosome worm burden after 8 weeks of infection were measured. The observed reduction of cercarial penetration was significant at 7.5 and 10 mg/l concentrations (p < 0.001). The mean number of worm burden declined from 28.5 worms/ mouse in untreated group to 4.4 worms/mouse with 7.5 mg/l treatment (p < 0.01). At a concentration of 10 mg/l, mice had no adult worm. The cercarial infectivity, as measured by the proportion of worms recovered in relation to the number of cercariae administrated, decreased with the increase in the extract concentration and was significant at a concentration of 7.5 mg/l (p < 0.01). The number of schistosome eggs in hepatic tissue decreased in treated mice. The reduction in egg count (per gram liver) was significant at 5 mg/l (p < 0.05) and 7.5 mg/I (p < 0.001). The treatment with Solanum water extract had no effect on female fecundity. These data point to Solanum as a promising agent for the control of schistosomiasis.