In vitro Anti‑Leishmanial Activity of Satureja khuzestanica Jamzad and Oliveria decumbens Vent. Extracts on Leishmania major and Leishmania infantum Promastigotes

Background and Objectives: Leishmaniasis is the main health problem and affects millions of people, especially in developing countries. On the other hand, there is no immunoprophylaxis (vaccination) accessible for the treatment of Leishmania infections and commercial drugs are unsatisfactory. Therefore, there is an effort to find alternative herbal remedies. The objective of the present study was to state the antileishmanial activity of two herbal medicines such as Satureja khuzestanica Jamzad and Oliveria decumbens Vent. leaf extracts on the promastigotes of Leishmania major and Leishmania infantum. 
Materials and Methods: The hydroethanolic extracts of each plant were extracted and their antileishmanial effects evaluated in different concentrations (0–156 μg/ml) and at various hours (24, 48, and 72 h) using colorimetric (3[4, 5dimethylthiazol2yl]2, 5 diphenyltetrazolium bromide) assay. The concentrationresponse curves of tested extracts and glucantime solutions as a reference were designed, and 50% of inhibitory concentration (IC50) values were recorded. 
Results: Antileishminal activity of S. khuzestanica, O. decumbens, and glucantime drug on L. major and L. infantum promastigotes were revealed with IC50 values of 4.3 and 5.5 μg/ml for S. khuzestanica, 0.85 and 0.23 μg/ml for O. decumbens, and 40.2 and 18.5 μg/ml for glucantime after 72 h incubation. 
Conclusion: These results revealed that compounds from S. khuzestanica and O. decumbens have antileishmania properties that necessary to survey the effects of these extracts on leishmania genus in animal models in the future.