Potencial parasiticida de Pimenta racemosa (Myrtales: Myrtaceae)

Abstract

American trypanosomiasis, leishmaniasis and schistosomiasis are parasitic diseases that affect millions of people in the world and are a serious public health problem, mainly in Latin American. Current treatments are not satisfactory, hence the need for new compounds. The objective of this work was to determine the bioactive potential of the plant Pimenta racemosa (Myrtales: Myrtaceae) against parasites. Different bioassays were carried out with different parts of the Pimenta racemosa plant to determine the toxic activity on Artemia salina, on human erythrocytes and its parasiticidal effect against Leishmania amazonenesis, Trypanosoma cruzi and Schistosoma mansoni. Lethal concentrations were calculated and PERMANOVA analyzes were performed. The results showed that P. racemosa does not produce a toxic or cytotoxic effect. It also showed no effect against L. amazonensis promastigotes or against T. cruzi epimastigotes, presented high lethal concentrations being determined that are not within the range to be considered bioactive. While P. racemosa showed parasiticidal activity against the immature forms of S. mansoni, causing greater mortality and morphological alterations in the miracidia than in the cercariae and an attenuation effect on S. mansoni cercariae was evidenced. The parts of P. racemosa fine branches presented the lowest LC50 of 0.10 mg/ml (0.08-0.14 mg/ml). Data are provided on the bioactivity of P. racemosa, no biological activity was evidenced against L. amazonensis and T. cruzi. However, P. racemosa presented a low cytotoxicity, with no toxic effect and biocidal activity against the immature forms of S. mansoni. Therefore, it is suggested to deepen the studies to potentiate its antiparasitic secondary metabolites against S. mansoni.