Objective: Meglumine antimonate, sodium stibogluconate and amfoterisin B are used in the treatment of cutaneous leishmaniasis which is the most common form in Turkey. Beside being highly toxic and costly, Leishmania parasites also have been reported to have developed resistance against meglumine antimonate and sodium stibogluconate in recent years. In this study, we aimed to investigate the in vitro susceptibility of water, aqueous ethanol and chloroform extracts of the leaves and fruits of Olea europaea against Leishmania tropica parasites.

Method: In vitro antileishmanial activities of Olea europaea plant extracts against Leishmania tropica isolates obtained from Manisa Celal Bayar University Faculty of Medicine with MHOM/TR/2012/CBCL-LT code, were investigated by using XTT and hemocytometer methods. Cytotoxic activities of plant extracts were also determined.

Results: Evaluation of antileishmanial activity showed that water of the aqueous ethanol and chloroform extracts of the leaves, and aqueous ethanol and chloroform extracts of the fruits had IC50 values as 6.77 mg/kg, 2.45 mg/kg, 6.50 mg/kg, 4.16 mg/kg, 0.23 mg/kg respectively. The water extract of fruits did not show any antileishmanial activity. Based on statistical comparison of these results with the control group, it was observed that fruit extract (p<0,05) showed no antileishmanial effect (p>0,05). Extracts other than leaf water extract (LC50 58.45 ?g/ml) of Olea europaea showed no cytotoxic activity.

Conclusion: As a result of this study chloroform extract of the fruits of Olea europaea ws found to have antileishmanial activity and this can be considered as an important and promising development in determination of antileishmanial active substances which was the main aim of this study.