Endlicheria bracteolata (Meisn.) Essential Oil as a Weapon Against Leishmania amazonensis: In Vitro Assay

Abstract

The difficulties encountered and the numerous side effects present in the treatment of cutaneous leishmaniasis have encouraged the research for new compounds that can complement or replace existing treatment. The growing scientific interest in the study of plants, which are already used in folk remedies, has led our group to test Endlicheria bracteolata essential oil against Leishmania amazonensis. Several species of the Lauraceae family, or their compounds, have relevant antiprotozoal activities Therefore, the biological potential on L. amazonensis forms from the essential oil of Endlicheria bracteolata leaves was verified for the first time in that work. The antileishmanial activity was evaluated against promastigotes and intracellular amastigotes, and cytotoxicity were performed with J774.G8, which were incubated with different concentrations of E. bracteolata essential oil. Transmission electron microscopy and flow cytometry were performed with E. bracteolata essential oil IC50. Promastigote forms showed E. bracteolata essential oil IC50 of 7.945 ± 1.285 µg/mL (24 h) and 6.186 ± 1.226 µg/mL (48 h), while for intracellular amastigote forms it was 3.546 ± 1.184 µg/mL (24 h). The CC50 was 15.14 ± 0.090 µg/mL showing that E. bracteolata essential oil is less toxic to macrophages than to parasites. Transmission electron microscopy showed that E. bracteolata essential oil treatment is capable of inducing mitochondrial damage to promastigote and intracellular amastigote forms, while flow cytometry showed ΔѰm disruption in treated parasites. These results could bring about new possibilities to develop products based on E. bracteolata essential oil to treat cutaneous leishmaniasis, especially for people who cannot receive the conventional therapy.

Carajurin Induces Apoptosis in Leishmania amazonensis Promastigotes through Reactive Oxygen Species Production and Mitochondrial Dysfunction

“…The anti-leishmanial activity of carajurin was evaluated in promastigote forms of L. amazonensis . Viable promastigotes were counted in a Neubauer chamber according to Rottini et al [ 16 ], with the percentage of growth inhibition calculated from the count of viable parasites in relation to the untreated control to determine the values of 50% of inhibitory concentration (IC 50 ). The results showed a significant concentration-dependent decrease ( p < 0.0001) in parasite viability ( Figure 2 ), with IC 50 at 7.96 ± 1.23 μg.mL − 1 (26.4 µM).…”

Aniba rosaeodora (Var. amazonica Ducke) Essential Oil: Chemical Composition, Antibacterial, Antioxidant and Antitrypanosomal Activity

“…Incubation took place in a 96-wells plate, in a BOD incubator at 28 °C in LIT medium using a parasite concentration of 10 6 promastigotes/mL. After 24 h, with the aid of the Neubauer chamber and light microscopy [ 46 ], viability was evaluated by counting parasites and the results were used to calculate the IC 50 (50% inhibition of parasite growth) following the formula: IC 50 = (sample counting)/(control counting) ×100 [ 47 ].…”

Membrane Disruption Properties of Essential Oils—A Double-Edged Sword?

“…Although the study showed varying levels of membrane disruption of tested compounds on different bacteria, the mechanism of action indicates a direct interference on the membrane lipid biosynthesis pathway [35]. Similar ultrastructural alterations were also observed through the accumulation and increase in electron density of lipid droplets in EO-treated parasitic cells via TEM [36,37].…”