Acyclic Sesquiterpenes from the Fruit Pericarp of Sapindus saponaria Induce Ultrastructural Alterations and Cell Death in Leishmania amazonensis.

Previous studies reported antiprotozoal activities of Sapindus saponaria L. The aim of this work was the evaluation of antileishmanial activity and mechanism of action of extract and fractions of S. saponaria L. Hydroethanolic extract (EHA) obtained from fruit pericarps was fractionated using solid-phase extraction in a reversed phase, resulting in fractions enriched with saponins (SAP fraction) and acyclic sesquiterpene oligoglycosides (OGSA fraction). The activities of EHA, SAP, and OGSA were evaluated by antiproliferative assays with promastigote and intracellular amastigote forms. Cytotoxicity on macrophages and hemolytic activity were also analyzed. Morphological and ultrastructural changes in Leishmania amazonensis promastigotes were evaluated by electron microscopy. Flow cytometry was used to investigate mitochondrial dysfunction and phosphatidylserine exposure. OGSA was more selective for parasites than mammalian J774A1 macrophage cells, with selectivity indices of 3.79 and 7.35, respectively. Our results showed that only the OGSA fraction did not present hemolytic activity at its IC50 for promastigote growth. Electron microscopy revealed changes in parasite flagellum, cell body shape, and organelle size, mainly mitochondria. Flow cytometry analysis indicated mitochondrial membrane and cell membrane dysfunction. OGSA showed antileishmanial activity, resulting in several changes to protozoa cells, including mitochondrial depolarization and early phosphatidylserine exposure, suggesting a possible apoptotic induction.

In vitro and in vivo antileishmania activity of sesquiterpene lactone-rich dichloromethane fraction obtained from Tanacetum parthenium (L.) Schultz-Bip.

The discovery of new treatments for neglected diseases, including leishmaniasis, is a substantial challenge for scientific research. Plant extracts have shown potential in the selective treatment of tropical diseases. The present study evaluated the in vitro and in vivo antileishmania effects of a sesquiterpene lactone-rich dichloromethane fraction (DF) obtained from the aerial parts of Tanacetum parthenium (L.) Schultz-Bip. In vitro studies of the DF indicated an IC50 of 2.40±0.76 µg mL(-1) against the promastigote form and 1.76±0.25 µg mL(-1) against the axenic amastigote form of Leishmania amazonensis. In vivo intramuscular treatment with DF decreased the growth and size of footpad lesions in mice. The DF also significantly decreased the parasite population compared with animals that were treated with the reference drug. Plasma malondialdehyde levels were increased slightly by the DF, attributable to its parthenolide-rich composition that causes cellular apoptosis, compared with the control group, demonstrating treatment efficacy without toxicity or genotoxicity. Because the isolation and purification of plant compounds are costly and time-consuming and generate low yields, extract fractions, such as the DF studied herein, represent a promising alternative for the treatment of leishmaniasis.