A Betulinic Acid Derivative, BA5, Induces G0/G1 Cell Arrest, Apoptosis Like-Death, and Morphological Alterations in Leishmania sp

Abstract

Leishmaniasis are endemic diseases caused by different species of intracellular parasites of the genus Leishmania. Due to the high toxicity and drug resistance of current antileishmanial drugs, it is necessary to identify new and more effective drugs. Previously, we investigated the immunomodulatory and anti-Trypanosoma cruzi action of BA5, a derivative of betulinic acid. In the present study, we investigated the in vitro activity of BA5 against different species of Leishmania and their action mechanism. BA5 exhibited low cytotoxicity against macrophages and inhibited the proliferation of promastigote forms of Leishmania amazonensis (IC50 = 4.5 ± 1.1 μM), Leishmania major (IC50 = 3.0 ± 0.8 μM), Leishmania braziliensis (IC50 = 0.9 ± 1.1 μM) and Leishmania infantum (IC50 = 0.15 ± 0.05 μM). Incubation with BA5 reduced the percentage of Leishmania amazonensis-infected macrophages and the number of intracellular parasites (IC50 = 4.1 ± 0.7 μM). To understand the mechanism of action underlying BA5 antileishmanial activity (incubation at IC50/2, IC50 or 2xIC50 values of the drug), we investigated ultrastructural changes by scanning electron microscopy and evaluated cell cycle, membrane mitochondrial potential, and cell death against promastigote forms of Leishmania amazonensis by flow cytometry. Promastigotes incubated with BA5 presented membrane blebbing, flagella damage, increased size, and body deformation. Flow cytometry analysis showed that parasite death is mainly caused by apoptosis-like death, arrested cell cycle in G0/G1 phase and did not alter the membrane mitochondrial potential of Leishmania amazonensis. Surprisingly, the combination of BA5 and amphotericin B, an assay used to determine the degree of drug interaction, revealed synergistic effects (CI = 0.15 ± 0.09) on promastigotes forms of Leishmania amazonensis. In conclusion, BA5 compound is an effective and selective antileishmanial agent.

Direct In Vitro Comparison of the Anti-Leishmanial Activity of Different Olive Oil Total Polyphenolic Fractions and Assessment of Their Combined Effects with Miltefosine

“…The above advocates the more potent anti-leishmanial properties of TPF2 in comparison to TPF1. To date, few studies have reported the association between synthetic drugs and natural compounds in the battle against leishmaniasis [ 43 , 44 , 45 ]. The additive effects of each TPF combination with miltefosine according to the FIC index, were further highlighted by the enhanced intracellular ROS production in Leishmania promastigotes treated with drug combinations compared to miltefosine-treated parasites.…”

Analysis of theLeishmania mexicanapromastigote cell cycle using imaging flow cytometry provides new insights into cell cycle flexibility and events of short duration

“…Due to biological variation and the cell cycle being a continuum, there is an overlap in the DNA contents of cells in G1 and early S phase, and of cells in late S and G2/M phases. To (8,45,46). Yet none of these methods consider the biology of the system nor can accurately classify the cell cycle stage of individual cells.…”