Interest in medicinal plants as a re-emerging health aid has been fuelled by increasing concern about the development of parasite resistance and the rising costs of prescription drugs in the maintenance of personal health and well-being, and the bioprospecting of new plant-derived drugs. Some plant extracts have been used worldwide in traditional medicine for the treatment of human helminthes but not all have been screened for activity against adult Schistosoma sp. The objective of this study was to evaluate the biological effects of crude extracts prepared from dried roots of Solanum incanum using experimental mice infected with Schistosoma mansoni, assessing the worm recovery and immunological responses after treatment. The mice were infected with a single dose of 250 Schistosoma mansoni cercariae and treated with the aqueous and methanol crude extracts at a specific time point. Evaluation on the number of worms recovered and the humoral and cellular immune responses was made. The results obtained showed a 16.7% maturation of penetrant cercariae. The Solanum incanum aqueous group recorded the highest worm reduction of 46.3% compared to control infected animals with 53.7% worm recovery observed. Cytokine levels peaked during the acute infection and declined to detectable levels after treatment. There was a marked rise in SWAP specific Interleukin-5 and also a rise in 0-3hr and SWAP specific IgG regardless of the time point after treatment. IL-5 production was significantly greater in the infected control and the treatment groups (p<0.05). 0-3hr and SWAP induced gamma interferon production however did not increase after treatment.