817 Document heading doi:10.12980/JCLM.2.201414D107 襃 2014 by the Journal of Coastal Life Medicine. All rights reserved. Evaluation of the in vivo effect of ivermectin on Schistosoma mansoni in experimentally-infected mice Amira Taman 1* , Samar El-Beshbishi 1 , Nora El-Tantawy 1 , Amira El-Hawary 2 , Manar Azab 1 1 Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt 2 Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt Journal of Coastal Life Medicine 2014; 2(10): 817-823 *Corresponding author: Amira Taman, PhD, Department of Medical Parasitology, Faculty of Medicine, Mansoura University, 2 El-Gomhouria Street, Mansoura 35516- Egypt. Tel: +2-050-2244873 Fax: +2- 050-2263717 E-mail: amirataman@mans.edu.eg 1. Introduction Schistosomiasis, caused by the trematode flatworms of the genus Schistosoma, is one of the most neglected tropical diseases with major public health significance in terms of morbidity and mortality. Recent estimates indicate that more than 230 million people are affected in 76 countries [1] , about 779 million are at risk of contracting the infection and 280 000 cases died in each year in sub-Saharan Africa because of schistosomiasis [2,3] . The burden of infection occurs in rural areas; however, with increased travelling, European and North American travellers are occasionally become infected. Five major species causing human schistosomiasis of which Schistosoma mansoni (S. mansoni), the aetiological agent of intestinal schistosomiasis, is endemic in 54 countries [4] . Currently, praziquantel is the only anti-schistosomal agent. Although it is safe and highly effective in a single dose regimen, the problem of worm resistance is a big threat, as low efficacy of praziquantel in the treatment of schistosomiasis has been reported in Senegal and Egypt [5,6] . No safe, effective alternative drug for treatment of schistosomiasis exists. Moreover, in spite of more than 40 years of research to develop a vaccine for schistosomes, no effective vaccine candidate exists, and praziquantel remains the mainstay for schistosomiasis control [7] . This makes the discovery and development of praziquantel alternatives is very important. Great efforts by various research groups are going to develop novel anti-schistosomal agents either synthetic or from natural compounds. As a relatively time-saving and cost-effective approach, scientists started to test the available compounds in the market, which have some antiparasitic activities. Among them, the antimalarials ARTICLE INFO ABSTRACT Objective: To evaluate the effect of ivermectin on mice experimentally infected with Schistosoma mansoni. Methods: Ivermectin was given to mice 42 days p.o. in two treatment regimens: a single dose of 25 mg/kg or the same dose for two consecutive days. Results: In both regimens, there were significant reductions in female worms, hepatic tissue egg count and early immature ova, in addition to significant reductions in the count and size of hepatic granuloma. The same dose for two consecutive days resulted in significant reductions in male, total worms, and intestinal tissue egg load. In both regimens, scanning electron microscopy revealed tegumental alternations as bleb formation, erosion and necrosis more evident with the double dose. In addition, high dose showed extensive erosions of male worms with destruction of the gynaecophoric canal. In females, marked destruction of the tegumental surface was extending to both ventral and oral suckers. Conclusions: Ivermectin has promising anti-schistosomal effects. However, further research is needed to test the effect of ivermectin on schistosomiasis especially in combination with other antischistosomal agents, to avoid any possible resistance from monotherapy. Article history: Received 2 Apr 2014 Received in revised form 10 Apr, 2nd revised form 13 Apr, 3rd revised form 20 Apr 2014 Accepted 10 May 2014 Available online 18 Jun 2014 Keywords: Schistosoma mansoni Ivermectin Praziquantel Scanning electron microscopy Tegument Glutamate journal homepage: www.jclmm.com Journal of Coastal Life Medicine