en تحقيقي Original Paper <div> <p><strong>ABSTRACT</strong></p> <p><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Background and Objective:</strong><em> Leishmania major</em> is a flagellate protozoan parasite causing cutaneous leishmaniasis. Although pentavalent antimony compounds are the first-line drugs for leishmaniasis, their application is often accompanied by numerous limitations and side effects. Therefore, it is necessary to seek drugs of herbal origin that have fast-acting benefits and few side effects without resistance. This study aimed to evaluate the in vitro effects of methanolic extract of <em>Arctiul lappa</em> root on promastigotes and amastigotes of<em> L. major</em>.</p> <p><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods: </strong>This experimental study evaluated the effects of 10, 100, 500, and 1000 &micro;g/ml of <em>A. lappa</em> root methanol extract on <em>L. major</em> promastigotes using direct cell counting and MTT assay. The mean number of amastigotes in infected macrophages was calculated after 24 and 48 hours.</p> <p><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Results</strong>: The half maximal inhibitory concentration (IC₅₀) of <em>A. lappa</em> root methanolic extract was 131.25 &micro;g/ml after 24 hours. The mean number of amastigotes in macrophages after 24 hours in the control group and in the <em>A. lappa</em> group with concentrations of 500 and 1000 &micro;g/ml were 3.52, 2.02, and 1.27, respectively.</p> <p><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Conclusion:</strong> The results show that the methanolic extract of <em>A. lappa</em> root has anti<em>-</em>leishmanial effects on the promastigotes and amastigotes of <em>L. major</em> in vitro.</p> <p><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keywords:</strong> <em>Leishmania Major</em>, Amastigotes, Promastigotes, <em>Arctium.</em></p> </div> Leishmania Major, Amastigotes, Promastigotes, Arctium. 50 45 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1-425&slc_lang=en&sid=1 Asghar Farghi Yamchi 100319475328460011509 100319475328460011509 No Department of Parasitology, Zabol University of Medical Sciences Mansour Dabirzadeh 100319475328460011510 100319475328460011510 Yes Department of Parasitology & Mycology Abdolhossein Miri dabirzadeh@zbmu.ic.ir 100319475328460011511 100319475328460011511 No Department of Pharmacognosy