Efficacy of Oral Artemisinin and Praziquantel Chemotherapy on Schistosoma mansoni Infected Mice by Means of Parasitological Parameters

Aim: Praziquantel-based chemotherapy is generally effective in the control of morbidity, decline in the prevalence and intensity of Schistosoma mansoni infections. Nevertheless, the potential emergence of praziquantel resistance in S. mansoni posses danger in the elimination of this neglected tropical disease in Africa. Therefore, this study was designed to evaluate the in-vivo efficacy of Praziquantel and Artemisinin using mice infected with S. Mansoni cercariae.

Methods: Infected mice with S. mansoni were treated with different doses of Artemisinin and Praziquantel from day 42 post infection to assess its efficacy on adult worms and eggs. A 2-day Protocol: artemisinin 400 mg/kg with Praziquantel of 500 mg/kg daily, 4-day protocol: artemisinin 200 mg/kg with praziquantel of 250 mg/kg daily, 6-day protocol: artemisinin 100 mg/kg with praziquantel of 125 mg/kg daily were used. A value of p <0.05 was considered as the level of significance using statistical package for social sciences (SPSS) version 21.

Results: Of the 150 snails collected, 60(40%) were confirmed to be Biomphalaria, while 50(33.3%) and 40(26.3%) were Bulinus and Intercalatum respectively. Highest reduction of 66.3% was found in group II, compared with 58.8% and 56.5% significant reductions in groups I and III, respectively. Also, there were 77.8% and 74.2% significant reductions in eggs per gram of the small intestinal tissue noted in groups I and II respectively as against 63.1% reduction in group III. A significant decline in the percentage of total immature stages of 6.14% in group I was observed when compared to 66.14% in the control. Furthermore, a statistically significant boost of 57.57% was found in the protocol of Artemisinin 100 mg/kg with Praziquantel 125 mg/kg daily (6-day protocol) causing decreases of 43.9% and 42.4% in the total and female worm loads, respectively. The combination decreased intestinal tissue egg loads ranging from 63.1% to 77.8% and liver egg loads ranging from 56.5% to 66.3% rates.

Conclusion: Combined effect of the drugs has confirmed some level of efficacy on experimental S. Mansoni with significant reduction in tissue egg burden.