Synthetic Curcuminoid Induces Cell Death in Trypanosoma cruzi Through Oxidative Stress and Exhibits Synergistic Activity with Benznidazole

BACKGROUND: Benznidazole is currently one of the few drugs available for the treatment of Chagas disease; however, it is associated with significant limitations, including adverse drug reactions and reduced or absent efficacy during the chronic phase. Given the inadequacy of existing therapies, this study investigates the potential therapeutic effect of the synthetic curcuminoid derivative (1E,4E)- 1,5-bis(4-methoxyphenyl)penta-1,4-dien-3-one (DBOCH3) against T. cruzi Y strain using both in vitro and in silico approaches. RESULTS: In vitro cytotoxicity assays demonstrated that treatment of LLC-MK2 cells with DBOCH3 resulted in a selectivity index of 36, which is 15 times higher than that of benznidazole. Furthermore, DBOCH3 exhibited inhibitory activity against the main life forms of T. cruzi: epimastigotes, trypomastigotes, and amastigotes. Checkerboard matrix assays based on the Bliss independence model revealed that the combination of DBOCH3 and benznidazole exerted a potent synergistic effect against both epimastigote and trypomastigotes forms, particularly within specific concentration combinations, without induced significant toxicity in LLC-MK2 host cells. Flow cytometry analysis indicated that DBOCH3 was associated with parasite cell-death events indicated by 7-AAD and Annexin V-PE labeling, accompanied by cytoplasmic ROS accumulation and loss of mitochondrial transmembrane potential. In silico molecular docking studies revealed that DBOCH3 was predicted to interact with selected T. cruzi enzymes, with predicted binding poses in TcGAPDH and trypanothione reductase (TcTR), with more favorable (more negative) ΔG values than benznidazole. CONCLUSION​: These findings indicate that DBOCH3 appears to possess promising characteristics, suggesting that its synergistic potential with benznidazole might offer a viable strategy to enhance antichagasic efficacy and mitigate drug-associated toxicity.