Avaliação da atividade tripanocida in vivo e in vitro de extrato obtido por fluído supercrítico de Cecropia pachystachya trécul

Abstract

Overlooked Tropical diseases are a various group of transmittable diseases that affect millions of people, they are considered as a huge public health issue with strong emphasis in underdeveloped countries. Between the overlooked tropical diseases, includes the Sore disease or well known as Chagas disease, caused by the protozoan Trypanosoma cruzi, that is transmitted by the triatomines pic, laboratory accidents, vertically or by oral intake, and it causes the acute and chronic forms of the disease. The only available medication for Chagas disease treatment is the benzinidazole, which has several side effects, hindering the patient compliance. Plants and their extracts have been used in pursuit of alternatives of treatment for a large amount of diseases, and are important to the industry, because they can serve as source of raw materials to new medications. The use of herbs of the sort Cecropia, are among those with high medical potential, showing several bioactive components with distinct biological activities, being used for the treatment of many pathologies. The species Cecropia pachystachya belongs to the Family Urticaceae, is popularly known as baobab, and has in its composition tannin compounds, flavonoids, alkaloids and more. Due to the antimicrobial action already detected in baobab extracts, sought to evaluate its action in vitro and in vivo anti-Trypanosoma cruzi of an extract from the leaves of C. pachystachya, obtained by supercritical carbon dioxide. Were assessed the cytotoxicity on mice peritoneal macrophages, and the extract’s trypanocidal activity on different forms of T. cruzi in vitro. It was analyzed whether the extract would also act on parasites if taken orally by animals infected with trypomastigotes. Macrophages and parasites were treated with different concentrations (5, 10, 15, 25, 50, 100, 150, 175, 200, 300 µg/mL) of the extract diluted in half. There was no change in cell viability, but the extract had action against the epimastigotes forms with an Inhibitory concentration of 50% of the parasites (CI50) of 17,9 and Selectivity Index of 22,33 and for trypomastigotes the CI50 was 26.73 and the Selectivity Index was 14,96 compared to Benznidazole (reference medicine) where the CI50 were 3,13 and 7,30 respectively and the Selectivity Indexes were 22,33 and 14,96 respectively. In the in vivo experiments it was found that the orally administered extracts worsened the animals' condition, with higher parasitemia and lower survival, compared to untreated animals. The extract provided an anti-inflammatory condition in infected and treated animals, with a higher presence of plasma IL-10 and lower nitric oxide production by peritoneal macrophages. Furthermore, these animals had an accentuated Th2 response, with higher levels of IL-4. Thus, the baobab extract obtained by supercritical CO2 extraction showed trypanocidal activity in vitro, but showed no action in vivo in which its antiinflammatory action led to a worsening of the infection.