anti-leishmanial activity of zataria multiflora and thymus vulgaris essential oils against leishmania major: phytochemical analysis and therapeutic efficacy

Background :leishmaniasis, a neglected tropical disease, impacts millions, especially in resource-limited areas. objectives :this study examines the chemical composition and anti-leishmanial potential of zataria multiflora and thymus vulgaris essential oils against leishmania major, a key cause of cutaneous leishmaniasis (cl). methods :the chemical composition of z. multiflora and t. vulgaris essential oils was analyzed by gas chromatography-mass spectrometry (gc-ms). their anti-leishmanial effects against l. major promastigotes (31.25 - 1000 µg/ml) were evaluated via flow cytometry, while anti-amastigote activity was determined by counting infected macrophages using light microscopy. cytotoxicity against j774 cells was assessed with the mtt assay after 48 hours. results :the main compounds in t. vulgaris and z. multiflora essential oils were thymol (49.83% and 46.46%, respectively), along with γ-terpinene (14.93%) and cymene (10.99%) in the former, and carvacrol (32.47%) in the latter. both oils showed activity against l. major promastigotes (ic50 = 92.75 and 59.69 µg/ml, respectively) and amastigotes (48 hours) (ic50 = 100.68 and 87.28 µg/ml, respectively). cytotoxicity on j774 cells (cc50 = 820.4 and 799.6 µg/ml) resulted in selectivity indices (si) of 8.84 (promastigote) and 8.14 (amastigote) for t. vulgaris, and 13.39 (promastigote) and 9.16 (amastigote) for z. multiflora. in the promastigote assay, amphotericin b [20 µg/ml, positive control (pc)] caused 89.71% mortality, confirming assay validity. conclusions :this study demonstrates the anti-leishmanial potential of z. multiflora and t. vulgaris essential oils against l. major, but further in vivo validation is required.