Mode of action of the sesquiterpene lactones eupatoriopicrin and estafietin on Trypanosoma cruzi

ELSO, ORLANDO; PUENTE, VANESA; BARRERA P; MIGUEL SOSA ESCUDERO; SULSEN, VALERIA; LOMBARDO, MARÍA E

PHYTOMEDICINE

ELSEVIER GMBH

Año: 2021 vol. 96

0944-7113

Background: : The sesquiterpene lactones (STLs) eupatoriopicrin (EP) and estafietin (ES), isolated from Steviaalpina Griseb. (Asteraceae) and Stevia maimarensis (Hieron.) Cabrera (Asteraceae) respectively, have previouslyshowed promising trypanocidal activity, both in vitro and in vivo.Purpose: : In this work, using biochemical studies and electron microscopy, we aimed at characterizing the modeof action of both STLs on Trypanosoma cruzi.Methods: : The interaction of STLs with hemin was examined by measuring modifications in the Soret absorptionband of hemin; the thiol groups interaction was determined spectrophotometrically through its reaction with5,5?-dithiobis-2-nitrobenzoate; the effect on cruzipain activity was also assayed by spectrophotometry. Thesynthesis of sterols were qualitatively and quantitatively tested by TLC. Mitochondrial functionality was assessedby measuring mitochondrial membrane potential and the activity of NADH-cytochrome c reductase andsuccinate-cytochrome c reductase enzymes. The status of the antioxidant system was assessed by quantifying thelevel of free thiols by spectrophotometry, together with the intracellular oxidative state by flow cytometry.Ultrastructural changes were analyzed by transmission electron microscopy.Results: : EP and ES were found to impair the functionality and the redox status of the parasite. ES produced agreater decrease in the activity of succinate dehydrogenase than eupatoriopicrin, affecting the functioning of therespiratory chain and the Krebs cycle. EP increased the formation of triglycerides leading to the presence ofcytoplasmic lipid droplets. By electron microscopy, alterations in the kinetoplast and the appearance of largetranslucent vacuoles in the cytoplasm were observed for both compounds.Conclusions: : Both sesquiterpenelactones proved to act additively on T. cruzi, supporting the hypothesis that eachcompound would be acting on different primary targets.. The treatment combining eupatoriopicrin and estafietincould be considered a promising alternative for the treatment of Chagas? disease.