Ferroquine is an ingenious antimalarial agent.
The 24 hours post-incubation all newly transformed schistosomula (NTS) exposed to 33.3 µM Ferroquine (FQ), hydroxyl-ferroquine (FQ-OH) and Ruthenoquine (RQ) shows strongly reduced viabilities. 72 hours post-incubation all NTS exposed to 33.3 µM RQ have died, while Ferroquine and FQ-OH treated worms are strongly affected but still alive[1].
Treatment of mice with 200 and 800 mg/kg Ferroquine, shows low total worm burden reductions of 19.4% and 35.6%. One of the mice treated with 800 mg/kg Ferroquine died within 24 hours post-treatment. No activity is observed treating mice with RQ at 200 mg/kg. Finally, a total worm burden reduction of 17.3% is observed following treatment with FQ-OH. Hence, modification of Chloroquine (CQ) by a ferrocenyl or ruthenocenyl fragment does not increase the antischistosomal properties of CQ. For comparison, at 200 mg/kg mefloquine (MQ) achieves a much higher worm burden reduction of 72.3% in S. mansoni-infected mice. A higher effect against female adult S. mansoni is also observed in MQ treated mice pointing to a sex-specific interference of these drugs with the target. Furthermore, in one of the FQ-OH treated mice many dead worms are recovered and a hepatic shift (i.e. worms migrating to the liver) observed. Hence, Ferroquine and FQ-OH show weak antischistosomal activity in vivo[1].
[1]. Keiser J, et al. In vitro and in vivo antischistosomal activity of ferroquine derivatives. Parasit Vectors. 2014 Sep 4;7:424.