Immunohistopathological and biochemical changes in Schistosoma mansoni-infected mice treated with artemether

Objective: To investigate immune mechanisms possibly involved in the amelioration of histopathological changes in livers of Schistosoma mansoni-infected mice treated with artemether (ART), including liver functions and apoptotic changes. Methods: Male CD-1 Swiss albino mice were infected with Schistosoma mansoni and treated with praziquantel (PZQ) 6 weeks post-infection (PI) (500 mg/kg/day x2) and/or ART in double dose (each of 400 mg/kg) 4 and 6 weeks PI. Parasitological parameters, liver functions and histopathological changes including T-lymphocyte profile and apoptotic changes were assessed. Results: Eight weeks PI, although the reduction in worm burden in mice treated with ART plus PZQ was comparable to that in PZQ-treated mice, yet there was complete absence of eggs and typical granulomas. The ratio of T-helper/cytotoxic cells was in favor of T-helper in infected control and in mice treated with both drugs. This ratio was 0.9:1 and 0.7:1 in PZQ and ART-treated groups, respectively, with moderate apoptotic changes in the latter. All biochemical parameters expressing liver function were improved with all treatment regimens. Conclusions: Administration of ART in addition to PZQ resulted in absence of eggs and typical granulomas with less apoptotic changes than in ART-treated mice. Improved liver functions with higher apoptosis in ART-treated mice may suggest enhanced necrotic cell death/regenerative changes. © 2007 The British Infection Society.