en قارچ شناسی Mycology تحقيقي Original Paper <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Background and objectives:</strong> Leishmaniasis is a tropical disease caused by protozoan parasites from the genus <em>Leishmania</em>. In this study, we aimed at investigating the in vitro anti-leishmanial effect of essential oils of <em>Rosmarinus officinalis</em>, <em>Mentha pulegium</em>, <em>Foeniculum vulgare, </em><em>Lippia citriodora </em>and <em>Pelargonium graveolens</em>.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods:</strong> The essential oils were prepared from freshly dried and powdered plants with steam-distilled water. Iranian strain of <em>Leishmania</em> promastigotes was cultured in RPMI medium and the inhibitory effects of different concentrations (25, 32, 62.5, 125, 250, 500 and 1000 &mu;g/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.<span dir="RTL"></span><br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Results:</strong> The essential oils significantly decreased the number of promastigotes in a dose-dependent manner (P<0.05). However, the inhibitory effects of <em>F. vulgare</em> and <em>R. officinalis</em> essential oils were more profound compared to other essential oils. Moreover, concentrations of 500 and 1000 &mu;g/ml of these two essential oils exerted equal and more anti-leishmanial potency compared to glucantime, the first-line drug used for treatment of leishmaniasis.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Conclusion: </strong>Based on the results, it is recommended to evaluate the in vivo anti-leishmanial effects of the tested essential oils, particularly <em>F. vulgare</em> and <em>R. officinalis</em>. Rosmarinus officinalis, Mentha pulegium, Foeniculum vulgare, Lippia citriodora, Pelargonium graveolens, Leishmania 46 52 http://mlj.goums.ac.ir/browse.php?a_code=A-10-639-1&slc_lang=en&sid=1 Mojtaba Raeisi raeisi_mojtaba@yahoo.com 100319475328460018116 100319475328460018116 No Assistant Professor of Food Hygiene and Quality Control, Department of Nutrition, Faculty of Health, Golestan University of Medical Sciences Kamal Mirkarimi ak.mirkarimi@gmail.com 100319475328460018117 100319475328460018117 No Health Management and Social Development Research Center, Department of Public Health, School of Health, Golestan University of Medical Sciences, Gorgan, Iran Behrooz Jannat 100319475328460018118 100319475328460018118 No Halal Research Center of IRI, Fda, Tehran, Iran Bahman Rahimi Esboei 100319475328460018119 100319475328460018119 No Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical, Tehran, Iran Abdol Sattar Pagheh 100319475328460018120 100319475328460018120 No Infectious Disease Research Center, Birjand University of Medical Sciences, Birjand, Iran Zahra Mehrbakhsh 100319475328460018121 100319475328460018121 No Department of Biostatistics, Faculty of Health, Golestan University of Medical Sciences, Gorgan, Iran Fatemeh Ghaffarifar 100319475328460018122 100319475328460018122 No Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Oghlniaz Jorjani 100319475328460018123 100319475328460018123 Yes Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran Masoud Foroutan 100319475328460018124 100319475328460018124 No Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran