Effect of Methanolic Extract of Arctium lappa Root on Promastigotes and Amastigotes of Leishmania major in vitro

Background and objective: leishmania major is a flagellate protozoan parasite causing cutaneous leishmaniasis. although pentavalent antimony compounds are the firstline 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 arctiul lappa root on promastigotes and amastigotes of l. major. methods: this experimental study evaluated the effects of 10, 100, 500, and 1000 μg/ml of a. lappa root methanol extract on l. major promastigotes using direct cell counting and mtt assay. the mean number of amastigotes in infected macrophages was calculated after 24 and 48 hours. results: the half maximal inhibitory concentration (ic50) of a. lappa root methanolic extract was 131.25 μg/ml after 24 hours. the mean number of amastigotes in macrophages after 24 hours in the control group and in the a. lappa group with concentrations of 500 and 1000 μg/ml were 3.52, 2.02, and 1.27, respectively. conclusion: the results show that the methanolic extract of a. lappa root has antileishmanial effects on the promastigotes and amastigotes of l. major in vitro.