Bioactivity of miltefosine against aquatic stages of Schistosoma mansoni, Schistosoma haematobium and their snail hosts, supported by scanning electron microscopy

Miltefosine proved to have in vitro ovicidal, schistolarvicidal and lethal activity on adult worms of both Schistosoma species and has considerable molluscicidal activity on their snail hosts. Scanning electron microscopy revealed several morphological changes on the different stages of the parasite and on the soft body of the snail, which further strengthens the current evidence of miltefosine's activity. This is the first report of mollusicidal activity of miltefosine and its in vitro schistosomicidal activity against S.haematobium.This study highlights miltefosine not only as a potential promising lead compound for the synthesis of novel broad spectrum schistosomicidal derivatives, but also for molluscicidals.Miltefosine (hexadecylphosphocholine) is one of several alkyllysophospholipid derivatives collectively known as alkylphosphocholines that were originally developed as anticancer agents [1]. The biocidal action of miltefosine against Leishmania species was demonstrated in the mid 1980s [2,3] and since then, trials for its clinical evaluation have led to the licensing of miltefosine for the oral treatment of leishmaniasis in India, Colombia, and Germany [4-6]. Miltefosine is also active against a variety of protozoa, and more and more data have become available on its activity against other Kinetoplastidae (Trypanosoma cruzi and T. brucei) [7,8], Trichomonas vaginalis [9], Entamoeba histolytica [10] and several free living amoebas [11-13]. Apart from its antiprotozoal effect, various bioactivities of miltefosine have been reported; it has a broad spectrum antifungal activity [14], bactericidal activity against Streptococcus pneumoniae and other pathogenic Streptococci [15], and it is under investigation as a potential therapy against HIV infection [16]. The mechanism underlying broad range bioactivities and the target (s) is still unrevealed. Most recently, miltefosine was reported to have anthelminthic properties. In a study done in 2011 [17], miltefosine was