Abstract

The neglected Chagas disease, a zoonosis caused by the Trypanosoma cruzi parasite, has limited treatment options like nifurtimox and benznidazole, known for their toxic effects and controversial efficacy. Natural products present opportunities for therapeutic alternatives, particularly in Chile, which has a rich variety of endemic flora. This study focused on the Chilean Buddleja globosa, evaluating the antioxidant activities and biological effects of its methanolic extract (MET) and BG500, an enriched iridoid fraction (6-O-methylcatalpol), against T. cruzi trypomastigotes. Although the trypanocidal activity of the extract was significantly lower than that of nifurtimox (280 ± 3.5 vs. 5.0 ± 0.5), its selectivity was comparable (selectivity index > 15). The MET and enriched fraction also induced hyperpolarization of mitochondrial membrane potential (ΔΨm). In silico docking studies suggested that T. cruzi’s Old Yellow (OYE) could be a potential target for 6-O-methylcatalpol. This work provides the first report on the potential trypanocidal activity of a B. globosa extract, highlighting the need for further studies to connect ΔΨm and OYE inhibition to the effects of 6-O-methylcatalpol. © 2025 by the authors.