Animal experiment:

Mice[1]Mice are infected i.p. with 104 bloodstream trypomastigotes taken from an infected mouse and suspended in 0.1 mL of phosphate-buffered saline, pH 7.2. The infection is allowed to develop for 24 h before treatment is begun. Ten infected mice are used as controls and received only excipient, 1% carboxymethylcellulose by the i.p. route in a 0.1 ml volume. The other mice receive a single dose of the diluted or suspended Potassium Melarsonyl (20, 40, 60 μmol/kg) in the same manner. Six mice are used per dose. The trypanocidal activity is evaluated by the mean survival time of treated mice for each dose[1].

Melarsonyl (Melarsonic acid) is an anthelmintic agent which can inhibit parasite potently.

For acute infections produced by T. brucei brucei GVR, Potassium Melarsonyl exhibits trypanocidal activities. Potassium Melarsonyl (Trimelarsan) cures less than 50% mice at a dose of 25 μmol/kg for 4 consecutive days. At 60 μmol/kg, it cures all the mice in a chronic-infection model[1].

[1]. Loiseau PM, et al. Contribution of dithiol ligands to in vitro and in vivo trypanocidal activities of dithiaarsanes and investigation of ligand exchange in an aqueous solution. Antimicrob Agents Chemother. 2000 Nov;44(11):2954-61.