Mammea type coumarins isolated from Calophyllum brasiliense induced apoptotic cell death of Trypanosoma cruzi through mitochondrial dysfunction, ROS production and cell cycle alterations

Abstract

Chagas Disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi which affects 6-8 million people, mostly in Latin America. The medical treatment is based on two nitroimidazole compounds, which have limited effectiveness in the chronic phase of the disease and produce several adverse effects; consequently, there is an urgent need to develop new, safe, and effective drugs. Previous reports had shown that natural coumarins, especially mammea A/BA isolated from the tropical tree Calophyllum brasiliense, is a promissory molecule for developing new drugs, due to its potent activity, higher than benznidazole, selectivity, and its low toxicity in mice. However, its mode of action is still unknown. In the present work, we evaluated the mechanism of action of the coumarin mammea A/BA (93.6%), isolated from the tropical tree C. brasiliense on Querétaro strain (Tc1) of T. cruzi. This compound was tested in vitro on epimastigotes and trypomastigotes of T. cruzi for intracellular esterase activity, plasma membrane integrity, phosphatidylserine exposure, ROS production, mitochondrial membrane potential, caspase-like activity, DNA integrity, cell cycle and autophagy. Mammea A/BA showed a 50% lethal concentration (LC₅₀) of 85.8 and 36.9 μM for epimastigotes and trypomastigotes respectively. It affected intracellular esterase activity, produced important plasma membrane damage and induced phosphatidylserine exposure. An increase in reactive oxygen species (ROS) and decrease in mitochondrial membrane potential were detected. Caspase-like activity was present in both parasite forms producing DNA integrity damage. This compound also induced a cell cycle arrest in the G1 phase and the presence of autophagy vacuoles. The above data suggest that mammea A/BA induce cell death of T. cruzi by autophagy and apoptosis-like phenomena and support our suggestion that mammea A/BA could be a promising molecule for the development of new drugs to treat Chagas Disease.

Keywords: Apoptosis; Calophyllum brasiliense; Mammea type coumarins; Trypanocidal activity; Trypanosoma cruzi.