Anti-leishmanial and toxicity activities of some selected Iranian medicinal plants

Leishmaniasis is caused by protozoan parasites belonging to the genus Leishmania. Cutaneous leishmaniasis is the most common form of leishmaniasis in Iran. As there is not any vaccine for leishmaniasis, treatment is important to prevent the spreading of parasites. There is, therefore, a need to develop newer drugs from different sources. The aim of this study was to assess anti-leishmanial activity of the ethanolic extracts of 17 different medicinal plants against Leishmania major promastigotes and macrophage cell line J774. The selection of the hereby studied 17 plants was based on the existing information on their local ethnobotanic history. Plants were dried, powdered, and macerated in a hydroalcoholic solution. Resulting extracts have been assessed for in vitro anti-leishmanial and brine shrimp toxicity activities. Four plants, Caesalpinia gilliesii, Satureia hortensis, Carum copticum heirm, and Thymus migricus, displayed high anti-leishmanial activity (IC50, 9.76 ± 1.27, 15.625 ± 3.76, 15.625 ± 5.46, and 31.25 ± 15.44 μM, respectively) and were toxic against the J774 macrophage cell line at higher concentrations than those needed to inhibit the parasite cell growth (IC50, 45.13 ± 3.17, 100.44 ± 17.48, 43.76 ± 0.78, and 39.67 ± 3.29 μM, respectively). Glucantime as positive control inhibited the growth of L. major promastigotes with IC50 = 254 μg/ml on promastigotes (1 × 10(6)/100 μ/well) of a log phase culture, without affecting the growth of J774 macrophages. These data revealed that C. gilliesii, S. hortensis, C. copticum heirm, and T. migricus extracts contain active compounds, which could serve as alternative agents in the control of cutaneous leishmaniasis. The activity of these herbs against L. major promastigotes and macrophage cell line J774 was reported for the first time in our study.