Histological observations on the effects of artemether, fuvinazole and niridazole on Schistosoma japonicum schistosomulae in mouse liver

Mice, each infected with 500-1000 Schistosoma japonicum cercariae for 7 d, were given intragastrically artemether (methyl dihydroartemisinin) 300, fuvinazole (trans-5-acetylamino-3-[2-(5-nitro-2-furyl)-vinyl]-1,2,4-oxadiazole) 400 or niridazole 200 mg/kg/d for 2 d. From the d 8 to d 15 after the infection, the degeneration rates of schistosomulae were 47%+/-7% to 78%+/4% (artemether), 7%+/-4% to 81%+/-5% (fuvinazole) and 12%+/-5% to 80%+/-7% (niridazole). From the d 8 to d 15 after the infection, the histological alterations of schistosomulae in the liver of mice in artemether group were loose parenchymal tissue and vacuolation, and infiltration of lymphocytes around the worms. The schistosomulae in fuvinazole and niridazole group mice produced a swelling of tegument, extension of intestinal tube filled with hemoglobin and infiltration of polynuclear leucocytes around the schistosomulae. The incidences of coagulation necrosis in the mouse livers in the artemether, fuvinazole and niridazole group, from the d 8 to d 15 after the infection, were 52%, 30%, 90%, respectively.