Background: Leishmaniasis is one of the most neglected human diseases with an estimated global burden ranking second in mortality and fourth in morbidity among the tropicalinfections. Chemotherapy drugs like glucantime is the mainstay treatment in endemic areas of Iran. Drug resistance is increasingly prevalent, so search for alternative therapy is gathering pace. Medicinal herbs, like wormwood Artemisia, have chemical compounds effective against a number of pathogensObjectives: In this study, the efficacy of ethanol extract from
Artemisia absinthium (Asteraceae) against
Leishmania major was investigated in invitro different effective doses (1–40 mg/ml) of ethanol extracts from this medicinal herb. The L. major promastigote cell sensitivity and mortality or viability effects due to the addition of herbal extract were measured using the
MTT assay and the flow cytometry technique, respectively.Materials and Methods: The standard strain of
Leishmania major wer cultures in a brain heart infusion BHI, FBS and antibioticd ar temperture of 25 ± 2 C .the effectiveeness of different concentrations of herbal extracts in the stationary phase of growth was investidated using
MTT colometric assay at 48 and 72 hours.using the propodium iodide (PI) stain, the mortality rates on exposure to differrent doses of extracts after 2 hours were also monitored with the aid of a flow cytometry apparatus.Results:The outcome from
MTT colorimetric assay indicated that this medical herb was mitogenic at low dose of 1 and 2 mg and increased the mitotic divisions of parasites. At high concentrations, however, an inverse or inhibitory effect on the parasite was noted. The
IC50 was calculated to be 16.6 mg which was in line with that of others. The flow cytometry studies were in perfect conformity to these findings and exhibited that after 2 h exposure with the herbal medicine of wormwood, 50 % of parasitized cells underwent apoptosis with a dose of 101 mg/ml.Conclusion: There was one or more chemical compound within the herbal extract of wormwood which at high concentration control cell division and affect the relevant biochemical activity within mitochondria. At low concentrations, however, it showed the opposite effect. It led to mitotic cell divisions.