Metabolomic profiling for the identification of drug targets in trypanosomes

Deep inside the metabolic machinery of two of the world’s most neglected killers, a quiet revolution in drug discovery is underway. Trypanosomes—single-celled flagellated parasites responsible for African sleeping sickness and Chagas disease—have long frustrated researchers with their bizarre biochemistry and stubborn resistance to conventional drug development. Now, a comprehensive review published in Frontiers in Chemical Biology reveals how metabolomic profiling, a technique that maps the complete chemical fingerprint of living cells, is transforming the hunt for new medicines against these tropical pathogens.

The review, led by an international team of researchers spanning Spain, Venezuela, Canada, Brazil, the United Kingdom and Malaysia, systematically catalogues every published study in which untargeted metabolomics has been deployed to identify the molecular targets and modes of action of trypanocidal drugs. The findings arrive at a critical moment. While human African trypanosomiasis has been driven to fewer than 600 reported cases annually—a triumph of surveillance and vector control—Chagas disease continues to infect more than 7 million people worldwide, claiming over 10,000 lives each year. For the American form of the disease, current therapies remain deeply unsatisfactory, and the threat of drug resistance looms over both parasites.

Metabolomics works by measuring the relative abundance of hundreds of small molecules—typically under 1,500 daltons—inside cells treated with a drug, then comparing these chemical signatures against untreated controls. When researchers add a compound to cultured trypanosomes and quench their metabolism at different time points, the resulting metabolome reveals a cascade of perturbations. The substrate and product of the primary target enzyme accumulate or deplete first, while secondary effects ripple outward as the metabolic network attempts to adapt. This temporal dimension is crucial: by sampling at sublethal doses corresponding to EC50 or EC90 values, scientists can distinguish primary drug action from the parasite’s compensatory stress responses.

Among the most striking revelations concerns suramin, a colossal, highly negatively charged molecule that has treated African sleeping sickness for over a century without anyone fully understanding how it works. The drug defies the Lipinski rule of 5, weighing 1,297 daltons and carrying six sulphonic acid groups. Trypanosomes internalize it by endocytosis, bound either to low-density lipoprotein or to the surface glycoprotein ISG75. Two independent metabolomic studies have now converged on a compelling explanation: suramin accumulates inside glycosomes, the peculiar peroxisome-related organelles that house the first six or seven enzymes of glycolysis, and there it inhibits the glycolytic flux. Researchers detected rising levels of fructose 6-phosphate, fructose 1,6-bisphosphate, glycerol 3-phosphate and pyruvate, alongside collapsing cytosolic ATP. Because glycosomes occupy only about one-twentieth of the cellular volume, a nine-fold cellular accumulation could translate into roughly 180-fold concentration within the organelles—enough to reach inhibitory levels against the positively charged glycosomal enzymes that suramin’s sulphonic acid groups mimic phosphate groups to block.

The polyamine pathway offers another elegant target story. Eflornithine, a suicide inhibitor of ornithine decarboxylase, exploits a unique vulnerability of African trypanosomes: unlike mammalian cells and Trypanosoma cruzi, these parasites lack a plasma-membrane transporter for polyamines and depend entirely on their own biosynthesis. Metabolomic profiling confirmed the mechanism with textbook clarity—ornithine accumulates, putrescine and spermidine plummet, and within 24 hours the parasites begin leaking phospholipids and other metabolites as their membranes, starved of the polyamines needed for stability, disintegrate. The drug is trypanostatic for 48 hours before killing occurs through delayed membrane damage and general metabolite loss.

Benzoxaboroles, the boron-containing compounds behind the newly developed single-dose oral drug acoziborole, reveal yet another layer of metabolic detective work. Genomic resistance studies identified CPSF3, an RNA cleavage and polyadenylation specificity factor, as the primary target. But metabolomics added crucial mechanistic depth: within five hours of treatment, levels of S-adenosyl-L-methionine and 5′-methylthioadenosine surged, along with methylated and acetylated lysines. The pattern mirrored the effects of sinefungin, a known methylation inhibitor that blocks trans-splicing—the trypanosome-specific mRNA maturation process. The correlation between AdoMet accumulation and splicing inhibition was remarkably tight across a panel of benzoxaboroles with different potencies, confirming that the compounds disrupt methionine metabolism as a downstream consequence of CPSF3 blockade.

For Chagas disease, where the intracellular amastigote form hides from immune surveillance and from most drugs, metabolomic studies remain fewer but equally illuminating. Benznidazole, one of only two approved therapies, was shown to deplete the redox-active thiols trypanothione, homotrypanothione and cysteine while generating covalent adducts with cellular metabolites. The parasite’s trypanothione system—unique to trypanosomatids, where spermidine links two glutathione molecules to form the parasite’s equivalent of glutathione—represents a validated vulnerability. Meanwhile, the antimicrobial peptide cruzioseptin CZS-5, isolated from the skin of the frog Cruziohyla calcarifer, disrupted membrane integrity and energy metabolism simultaneously, with lipid-related molecules comprising nearly 57 percent of the 118 metabolites altered upon treatment.

Perhaps the most technically sophisticated application comes from a new methodology designed to triage cytochrome b inhibitors during Chagas disease drug discovery. Because phenotypic library screenings frequently identify hits against a small number of promiscuous targets, researchers developed a metabolomic signature—a list of 79 metabolites showing at least two-fold differential abundance—that distinguishes cytochrome b inhibition from other known targets including lysyl-tRNA synthetase, N-myristoyltransferase and the proteasome. The approach, validated with 17 different compounds, allows laboratories to deprioritize cytochrome b hits early in the workflow in favor of compounds acting through genuinely novel mechanisms.

The review also highlights how metabolomics can expose resistance mechanisms. Eflornithine resistance in African trypanosomes, for instance, arises from loss of the amino acid transporter TbAAT6, preventing intracellular drug accumulation—a finding that metabolomics alone could reveal because the mechanism produces a measurable decrease in intracellular drug concentration. For fluoropyrimidines like 5-fluorouracil and 5-fluoroorotic acid, metabolomic analysis showed incorporation into RNA rather than DNA, explaining why these compounds kill trypanosomes through a fundamentally different route than they do human cancer cells.

What emerges from this exhaustive survey is a discipline coming of age. Metabolomic profiling has limitations—data interpretation remains challenging, and primary effects must be carefully separated from secondary ones through time-course analysis. But when combined with reverse genetics, chemoproteomics and metabolic flux measurements, it provides an indispensable window into how drugs actually kill parasites. As sleeping sickness edges toward elimination and Chagas disease demands new safe therapies, the chemical fingerprints of trypanosome metabolism are proving to be the most powerful maps yet for navigating the path to better medicines.

Subject of Research: Metabolomic profiling for the identification of drug targets in trypanosomes

Article Title: Metabolomic profiling for the identification of drug targets in trypanosomes

Article References: Metabolomic profiling for the identification of drug targets in trypanosomes. (n.d.). https://doi.org/10.3389/fchbi.2026.1907625

Image Credits: AI Generated

DOI: 10.3389/fchbi.2026.1907625

Keywords: metabolomics, trypanosomes, drug discovery, sleeping sickness, Chagas disease, parasitology, glycosomes, trypanothione, Metabolomic, profiling, identification, drug