In Vitro Effect of Some Medicinal Plants on Leishmania major Strain MRHO/IR/75/ER

Background and objectives: Leishmaniasis is a tropical disease caused by protozoan parasites from the genus Leishmania. In this study, we aimed at investigating the in vitro anti-leishmanial effect of essential oils of Rosmarinus officinalis, Mentha pulegium, Foeniculum vulgare, Lippia citriodora and Pelargonium graveolens. Methods: The essential oils were prepared from freshly dried and powdered plants with steam-distilled water. Iranian strain of Leishmania promastigotes was cultured in RPMI medium and the inhibitory effects of different concentrations (25, 32, 62.5, 125, 250, 500 and 1000 μg/ml) of the essential oils were investigated at 24, 48 and 72 hours. The number of live parasites before and after treatment with the essential oils was counted by trypan blue 10% staining and using neobar lam. Results: The essential oils significantly decreased the number of promastigotes in a dose-dependent manner (P