Antitrypanosomal and Antileishmanial Effects of the Hydroalcoholic Extract of Croton cajucara Benth and its 19‑nor‑Clerodane Chromatographic Fractions

Objectives: The objective of the study is to evaluate the stem bark hydroalcoholic extract (CC‑EHA) of C. cajucara and their clerodane‑type diterpene fractions (F1‑7, F25‑27, and F28) on promastigotes and axenic amastigotes of Leishmania amazonensis and trypomastigotes and epimastigotes of Trypanosoma cruzi. Materials and Methods: The extract was obtained in ethanol: water and the fractions with solvents of increasing polarity. The antiparasitic activities were assessed by 3,4,5‑dimethylthiazol‑2‑yl‑2,5‑diphenyltetrazolium bromide method against promastigotes and axenic amastigotes from L. amazonensis in 24‑h cultures and trypomastigotes and epimastigotes of T. cruzi in 72‑h cultures. The experiments in triplicate were made in quadruplicate way in each time. The statistical tests used were t-Students and ANOVA. Results: Among those evaluated samples, the CC‑EHA extract showed the higher antileishmanial activity of promastigote cultures (IC50 = 18.00 ± 0.01 µg/mL at 24 h). However, against axenic amastigotes, the polar fraction (F28), rich in diterpene transdehydrocrotonin (t‑DCTN), showed the highest effect with an IC50 = 6.18 ± 0.02 µg/mL in culture of 24 h. In the T. cruzi assays, F28 also showed the greatest effect against trypomastigotes and epimastigotes, IC50 = 0.43 ± 0.02 µg/mL and 0.27 ± 0.02 µg/mL, respectively, at 72 h of culture. The results showed that the diterpene t‑DCTN is the most important antiparasitic component in the hydroalcoholic extract obtained from C. cajucara, specifically against L. amazonensis and T. cruzi. Conclusion: Our results contribute to knowledge of these folk medicinal species as a promising antiparasitic phytotherapeutic alternative.