EFFECT OF ARTESUNATE ON JUVENILE AlD ADULT STAGES OF SCHISTOSOMA MANSONI IN MICE

Abstract

BACKGROUND: Chemotherapy with praziquantel remains' the mainstay of control of the schistosomiasis, The derivatives of artemisinin, artemether and artesunate are also known to exhibit antischistosomal activities. The aim of this study was to assess the effect of artesunate on different developmental stages of an Ethiopian strain of Schistosoma ntansoni in mice_

METHODS: A total of 49 male Swiss albino mice were used and each was exposed to 100 cercariae _of Schistosoma mansoni and randomly grouped into 9 groups. Mice in group 1 served as controls and were not treated. Mice in-group 2 were orally treated with 4 mg/kg of artesunate on day 7 and then with 2 mg/kg on days 14, 21, 28 and 35- post exposure to cercariae. Mice in groups 3, 4 and 5 were orally treated with 50, 100 and 200 mg/kg artesunate on days 7, 14, 21, 28 and 35 post-exposure to cercariae, respectively. Mice in-group 6 were orally treated with 4 mg/kg artesunate on day 50 and then with 2 mg/kg for four consecutive days. Mice in groups 7, 8 and 9 were treated with 50, 100 and 200-mg/kg of artesunate on days 50-56 post- exposure to cercariae, respectively. The mice were followed for worms development and reduction.

RESULTS: Doses of 100 and 200 mg/kg of artesunate administrated to mice on days 7, 14, 21, 28 and 35 post-infection resulted in total worm burden reductions of 61.4 -81.4%, which was significantly higher than the percentage of total worm burden reductions obtained with the same doses administrated on days 50-56 post-infection (20.7-21.4%, P.< 0.05). Administration of 4 mg/kg and then 2 mg/kg or 50 mg/kg artesunate either between days 7-35 or on days 50-56 post-exposure to cercariae did not affect the juvenile stages or the adult worms of S. mansoni.

CONCLUSION: Artesunate appears to be more effective against juvenile stages of S. mansoni than adult worms in mice when it is administered at higher doses. Therefore, further studies are needed in humans to provide additional data on the efficacy of artesunate and other derivatives of artemisinin in the treatment of schistosomiasis. (Ethiop Health Sci 2005; 15(4.31-38).