Pheophorbide a, a compound isolated from the leaves of Arrabidaea chica, induces photodynamic inactivation of Trypanosoma cruzi

- Fractions of Arrabidaea chica showed good activity in forms of Trypanosoma cruzi.
- Interestingly we found a photosensitizer compound with the bioassay-guided.
- Pheophorbide a, had an excellent activity against T. cruzi, in the light presence.
- The photodynamic therapy with pheophorbide a inactive trypomastigote forms.
- Pheophorbide a, can be used in blood banks for hemoprophylaxis.

BackgroundApproximately 6-7 million people are infected with Trypanosoma cruzi, the etiological agent of Chagas' disease. Only two therapeutic compounds have been found to be useful against this disease: nifurtimox and benznidazole. These drugs have been effective in the acute phase of the disease but less effective in the chronic phase; they also have many side effects. Thus, the search for new compounds with trypanocidal action is necessary. Natural products can be the source of many important substances for the development of drugs to treat this infection. The present study evaluated the biological activity of an extract and fractions of Arrabidaea chica against T. cruzi and observed morphological and ultrastructural characteristics of parasites exposed to the isolated compound pheophorbide a.MethodsThe crude hydroethanolic extract of A. chica was prepared. Fractions were obtained by partition and separated by liquid chromatography.ResultsWe observed a progressive increase in activity against epimastigote, trypomastigote, and amastigote forms of the parasite over the course of the fractionation process. Interestingly, we isolated a compound known as a photosensitizer that is used in photodynamic therapy. This method of treatment involving a photosensitizer, activation light and molecular oxygen is of great importance due to its selectivity. Pheophorbide a had activity against the protozoan in the presence of light and caused morphological and ultrastructural changes, demonstrating its potential in photodynamic therapy.ConclusionsBased on the ability of pheophorbide a to eliminate bloodstream forms of T. cruzi, we suggest its use in blood banks for hemoprophylaxis.