Efficacy of anticancer alkylphosphocholines in Trypanosoma brucei subspecies

Tetradecylphosphocholine (TPC), hexadecylphosphocholine (HPC), hexadecylphospho(N-N-N-trimethyl)hexanolamine (HPC6), octadecylphosphocholine (OPC), and octadecyl-[2-(N-methylpiperidinio)ethyl]-phosphate (OMPEP) were investigated for antitrypanosomal activity in vitro and in vivo. OMPEP showed the best trypanocidal efficacy in vitro: it was superior to the model compound HPC and comparable to the reference compound α-DFMO. HPC showed moderate activity in vivo in terms of increased life expectancy (up to 35% in the acute NMRI-mouse model or 49% if combined with phenylbutazone) and increased packed cell volume, if administered daily. However, HPC and the other alkylphosphocholines failed to prolong survival time of treated mice if given intermittently. Phenylbutazone had no own trypanocidal effect but increased the efficacy of alkylphosphocholines in vitro and in vivo: the combination of HPC and phenylbutazone acted apparently synergistic.