Effects of miltefosine treatment in fibroblast cell cultures and in mice experimentally infected withNeospora caninumtachyzoites

Abstract

<jats:title>SUMMARY</jats:title><jats:p>Miltefosine was investigated for its activity against<jats:italic>Neospora caninum</jats:italic>tachyzoites<jats:italic>in vitro,</jats:italic>and was shown to inhibit the proliferation of<jats:italic>N. caninum</jats:italic>tachyzoites cultured in human foreskin fibroblasts (HFF) with an IC<jats:sub>50</jats:sub>of 5·2<jats:italic>μ</jats:italic>M. Treatment of infected cells with 25<jats:italic>μ</jats:italic>M miltefosine for a period of 10 h had only a parasitostatic effect, while after 20 h of treatment parasiticidal effects were observed. This was confirmed by transmission electron microscopy of<jats:italic>N. caninum</jats:italic>-infected and miltefosine-treated HFF. Administration of miltefosine to<jats:italic>N. caninum</jats:italic>-infected Balb/c female mice at 40 mg/kg/day for 14 days resulted in 6 out of 10 mice exhibiting weight loss, ruffled coat and apathy between days 7 and 13 post-infection. In the group that received placebo, only 2 out of 8 mice succumbed to infection, but the cerebral burden was significantly higher compared to the miltefosine treatment group. In a second experiment, the time-span of treatment was reduced to 5 days, and mice were maintained without further treatment for 4 weeks. Only 2 out of 9 mice in the miltefosine treatment group exhibited signs of disease, while 8 out of 10 mice succumbed to infection in the placebo group. These results showed that miltefosine hampered the dissemination of parasites into the CNS during experimental<jats:italic>N. caninum</jats:italic>infection in mice.</jats:p>

Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice

“…In short term (4-day) proliferation assays, BPQ was active with an IC 50 of 4.9 nM, which is one of the lowest values reported so far for drugs that were assessed against N. caninum in vitro . The IC 50 for miltefosine was 5 µM ( Debache and Hemphill, 2012 ), and two dicationic compounds (the arylimidamides DB745 and DB750) inhibited N. caninum proliferation in vitro with IC 50 s of 80–160 nM ( Debache et al., 2011; Schorer et al., 2012 ). More recently, the bumped kinase inhibitor (BKI) 1294, which is targeted against the calcium dependent protein kinase 1 (CDPK1), was shown to inhibit N. caninum in vitro proliferation with an IC 50 of 30 nM ( Ojo et al., 2014 ).…”

“…Nevertheless, experimental studies have revealed potentially interesting effects of several compounds in vitro and in laboratory animal models in vivo ( Müller and Hemphill, 2011 ). Other publications reported on further promising drug candidates including toltrazurilsulfone (ponazuril) ( Kritzner et al., 2002; Strohbusch et al., 2009 ), artemisone ( Mazuz et al., 2012 ), di-cationic diamidine derivatives ( Debache et al., 2011; Schorer et al., 2012 ), miltefosine ( Debache and Hemphill, 2012 ), organometallic ruthenium complexes ( Barna et al., 2013 ) and bumped kinase inhibitors ( Ojo et al., 2014 ).…”

In VitroEffects of Novel Ruthenium Complexes in Neospora caninum and Toxoplasma gondii Tachyzoites

“…Chemotherapy has been considered a promising option if effective drugs can be identified (12,13). Several compounds were investigated in vitro (14)(15)(16), but only a few were evaluated in small-animal models (14,(17)(18)(19)(20)(21)(22)(23)(24).…”

Dose-dependent effects of experimental infection with the virulent Neospora caninum Nc-Spain7 isolate in a pregnant mouse model

“…In addition, very different outcomes have been observed between non-pregnant and pregnant mice (reviewed in Monney and Hemphill, 2014). BALB/c mice are the most widely employed mouse breed for studies on Neospora infection biology (López-Pérez et al, 2010;Regidor-Cerrillo et al, 2010;Dellarupe et al, 2014) and as proof-of-concept model for the assessment of drugs (e.g., Debache et al, 2011;Debache and Hemphill, 2012;Schorer et al, 2012;Ojo et al, 2014). Most notably, the pregnant BALB/c model has demonstrated various degrees of efficacy for a number of vaccine candidates (e.g., Aguado-Martínez et al, 2009;Debache et al, 2009;Zhang et al, 2010;Marugán-Hernández et al, 2011;Monney et al, 2012;Rojo-Montejo et al, 2012), and enabled researchers to assess the effects of parasite infection and respective vaccines on both progeny and dams (López-Pérez et al, 2008).…”