The Anti-leishmanial Efficacy of Artemisia dracunculus Ethanolic Extract in Vitro and Its Effects on IFN- γ and IL-4 Response

Background: Leishmaniasis is a parasitic disease that appears with a range of
symptoms including cutaneous, mucocutaneous, and visceral leishmaniasis. The
present study sought to determine the antileishmanial effect of the extract of Artemisia dracunculus (Tarragon) compared to control treatment with pentavalent antimony (meglumine).
Methods: This experimental study was performed in 2014-2015. A. dracunculus
were collected from West Azerbaijan Province, Iran and dried; then the ethanolic
extract of the plant was prepared. The effect of different concentrations of Artemisia's extract was compared with Glucantime ® in the stationary phase by MTT
colorimetric assay and Trypan blue staining. Human peripheral blood mononuclear cells (HPBMCs) treated with L. major and production of IFN- γ and IL-4
cytokines measured at concentrations of 25, 20, 10 and 5µg/ml A. dracunculus.
Results: Treatment with the extract did not affect the survival of the parasites
during the first 48 h; however, on the third day (72 h), all concentrations
significantly reduced the number of parasites with an efficacy of more than 50%
at 10 µg/ml (P<0.01), 20µg/ml (P<0.001), and 25 µg/ml (P<0.0001). Moreover,
IFN-γ and IL-4 secretion from the HPBMCs was significantly affected in a dosedependent manner, compared to the control (no extract). The IFN-γ/IL-4 ratio
further confirmed this notion.
Conclusion: A. dracunculus extract cannot only exert potent antileishmanial
activity but may also enhance cellular immunity to this parasite. Further studies
are required to determine the main compound(s) responsible for these effects of
the plant.