Fasciola gigantica: Parasitological and scanning electron microscopy study of the in vitro effects of ivermectin and/or artemether

Abstract: Objective: To evaluate the in vitro effects of different concentrations of ivermectin and/or artemether on Fasciola gigantica worms and to study the parasitological changes and tegumental alterations using scanning electron microscopy (SEM). Methods: Fasciola gigantica worms were incubated in vitro for 24 and 48h with three concentrations of either ivermectin or artemether (10, 20 and 50μg/ml) or both in half concentration of either (5, 10 and 25μg/ml). Results: Exposure of Fasciola worms to 25+25μg/ml of combined drug regimens or to 50μg/ml of either ivermectin or artemether for 48h led to 100%, 41.7% and 75% worm killing which were accompanied by a significant reduction in egg laying capacity and significant increase in dead eggs maximally recorded in combined drug regimens. SEM of the flukes incubated for 48h with combined drug regimens showed maximal tegumental disruption with swelling of the worm body, roughness, blebbing, sloughing and complete loss of spines. Disruption to the tegument of the flukes induced by artemether was more than that of ivermectin. Conclusions: Artemether alone or combined with ivermectin in half doses had potent fasciocidal activities. Besides, half doses of combined drug regimens had higher ovicidal effects than each drug alone. In vivo studies are recommended to explore the efficacy of combined regimens against Fasciola infection. [Copyright &y& Elsevier]