Enyne acetogenins from Porcelia macrocarpa displayed anti-Trypanosoma cruzi activity and cause a reduction in the intracellular calcium level

Author(s)

Thevenard, Fernanda ; Brito, Ivanildo A. ; Costa-Silva, Thais A. ; Tempone, Andre G. ; Lago, Joao Henrique G.

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 13, n. 1, p. 10-pg., 2023-06-24.

Abstract

Natural products are a promising source of new compounds with a wide spectrum of pharmacological properties, including antiprotozoal activities. Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is one of several neglected tropical diseases with reduced options for treatment, which presents limitations such as toxicity and ineffectiveness in the chronic stage of the disease. Aiming to investigate the Brazilian flora for the discovery of new anti-T. cruzi compounds, the MeOH extract from Porcelia macrocarpa R.E. Fries (Annonaceae) fruit peels displayed potent activity against trypomastigotes and intracellular amastigotes and was subjected to bioactivity-guided fractionation. Using different chromatographic steps, a fraction composed of a mixture of four new chemically related acetogenins was obtained. The compounds were characterized as (2S*,3R*,4R*)-3-hydroxy-4-methyl-2-(n-octadeca-13 & PRIME;,17 & PRIME;-dien-11 & PRIME;-inil)butanolide (1), (2S*,3R*,4R*)-3-hydroxy-4-methyl-2-(n-eicosa-13 & PRIME;,19 & PRIME;-dien-11 & PRIME;-inil)butanolide (2), (2S*,3R*,4R*)-3-hydroxy-4-methyl-2-(n-octadec-13 & PRIME;-en-11 & PRIME;-inil)butanolide (3), and (2S*,3R*,4R*)-3-hydroxy-4-methyl-2-(n-eicosa-13 & PRIME;-en-11 & PRIME;-inil)butanolide (4) by NMR analysis and UHPLC/ESI-HRMS data. The mixture of compounds 1-4, displayed an EC50 of 4.9 and 2.5 & mu;g/mL against trypomastigote and amastigote forms of T. cruzi, respectively, similar to the standard drug benznidazole (EC50 of 4.8 and 1.4 & mu;g/mL). Additionally, the mixture of compounds 1-4 displayed no mammalian toxicity for murine fibroblasts (CC50 > 200 & mu;g/mL), resulting in a SI > 40.8 and > 83.3 against trypomastigotes and amastigotes, respectively. Based on these results, the mechanism of action of this bioactive fraction was investigated. After a short-time incubation with the trypomastigotes, no alterations in the cell membrane permeability were observed. However, it was verified a decrease in the intracellular calcium of the parasites, without significant pH variations of the acidocalcisomes. The intracellular damages were followed by an upregulation of the reactive oxygen species and ATP, but no depolarization effects were observed in the mitochondrial membrane potential. These data suggest that the mixture of compounds 1-4 caused an irreversible oxidative stress in the parasites, leading to death. If adequately studied, these acetogenins can open new insights for the discovery of new routes of death in T. cruzi. (AU)

• FAPESP's process: 21/02789-7 - Search for bioactive metabolites with antiparasitic action in plant species from Atlantic Forest and Cerrado regions - a chemical, phenotypical, and metabolomic approach
• Grantee: João Henrique Ghilardi Lago
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 21/04464-8 - Microbial and plant prototypes as drug candidates for protozoan neglected diseases and multidrug-resistant bacteria
• Grantee: André Gustavo Tempone Cardoso
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/01221-4 - Metabolites from fruit peels of Porcelia macrocarpa (Warm.) R. E. Fries (Annonaceae): molecular dereplication, evaluation of antiparasitic potential and study of the phenotypic and metabolomic modes of action
• Grantee: Fernanda Thevenard dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)