Effects of artemether on parasite burden and liver pathology in mice infected with Ibadan isolate of Schistosoma mansoni

Abstract

This study aimed at evaluating the pathological features associated with Schistosoma mansoni infection and assessment of the efficacy of artemether in the treatment of intestinal schistosomiasis in laboratory mice. Cercariae harvested from naturally infected Biomphalaria pfeifferi obtained from Odo Ona River in Ibadan, Oyo State, Nigeria, were used to infect Swiss albino mice in the laboratory. A total of 50 mice were divided into 5 groups and artemether (300mg/kg) was administered to two of the groups at 15th and 42nd day post-infection respectively, Praziquantel (600mg/kg) was administered to a group as the control drug and another group was used as the infected control group while the last group was uninfected. Mice were sacrificed and perfused at 8th week post-infection for worm recovery, examination of the visceral organs and histopathology were conducted on liver and spleen of infected and uninfected groups. Schistosoma mansoni isolate from Ibadan, caused severe liver pathology in mice, and thus presents features indicative of epidemiological importance in human schistosomiasis. Worm burden reduction (98%) was observed in mice treated at day 15 post-infection with artemether (300 mg/kg) while 77% worm reduction was observed in the group of mice treated at day 42 post infection with artemether (300 mg/kg). Granulomas were not observed in the liver of mice treated at day 15 post-infection while those of untreated group, which had multiple granulomas. Inflammatory cellular infiltrations were observed in liver of infected mice however, the mice treated at day 15 post-infection had mild infiltration likely due to fewer eggs present in the liver. Praziquantel used as the routine control drug was less effective compared to artemether. Worm reduction (53%) was recorded for mice treated with praziquantel, gross and histopathology also revealed eggs diffusely deposited in the liver of the mice. Artemether, a derivative of artemisinin, showed a good antischistosomal effect that could be an alternative and/or complement praziquantel in the control of schistosomiasis in endemic areas.

Keywords: Artemether; Schistosoma mansoni; Ibadan isolate; Swiss albino mice; gross pathology; histopathology.