Determination of the Optimal Single Dose Treatment for Acoziborole, a Novel Drug for the Treatment of Human African Trypanosomiasis: First-in-Human Study

Antitrypanosomal Chloronitrobenzamides

Human African trypanosomiasis (HAT), a neglected tropical disease caused by Trypanosoma brucei gambiense (Tbg) or Trypanosoma brucei rhodesiense (Tbr), remains a significant public health concern with over 55 million people at risk of infection. Current treatments for HAT face the challenges of poor efficacy, drug resistance, and toxicity. This study presents the synthesis and evaluation of chloronitrobenzamides (CNBs) against Trypanosoma species, identifying previously reported compound 52 as a potent and selective orally bioavailable antitrypanosomal agent. 52 was well tolerated in vivo and demonstrated favorable oral pharmacokinetics, maintaining plasma concentrations surpassing the cellular EC50 for over 24 h and achieving peak brain concentrations exceeding 7 μM in rodents after single oral administration (50 mg/kg). Treatment with 52 significantly extended the lifespan of mice infected with Trypanosoma congolense and T. brucei rhodesiense. These results demonstrate that 52 is a strong antitrypanosomal lead with potential for developing treatments for both human and animal African trypanosomiasis.

Therapeutic Potential of Marine-Derived Cyclic Peptides as Antiparasitic Agents

Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable efficacy, and long treatment, which have encouraged drug resistance. There is an urgent need to find new, safe, effective, and affordable antiparasitic drugs. Marine-derived cyclic peptides have been increasingly screened as candidates for developing new drugs. Therefore, in this review, a systematic analysis of the scientific literature was performed and 25 marine-derived cyclic peptides with antiparasitic activity (1-25) were found. Antimalarial activity is the most reported (51%), followed by antileishmanial (27%) and antitrypanosomal (20%) activities. Some compounds showed promising antiparasitic activity at the nM scale, being active against various parasites. The mechanisms of action and targets for some of the compounds have been investigated, revealing different strategies against parasites.