In vitro antileishmanial activity of methanolic and aqueous extracts of Eucalyptus camaldulensis against Leishmania major

Pentavalent antimony compounds are expensive, toxic and drug resistance is prevalent, whereas the plant extract derivatives are safe. In the present study, the effect of methanolic and aqueous extracts of Eucalyptus camaldulensis on the promastigotes of Leishmania major was evaluated. The methanolic and aqueous extracts of E. camaldulensis leaves were prepared. The compounds were dried and powdered. Serial dilutions of the extracts and control drugs in phosphate buffer solution were prepared. The stationary phase promastigotes of L. major were incubated to the methanolic and aqueous extractions in vitro. Tartar emetic was used as the positive control drug. After 72 h of incubation the activity of the extracts was measured, using MTT method. The IC50 values (50 % inhibitory concentration) were 586.2 ± 47.6 and 1,108.6 ± 51.9 μg/ml for methanolic and aqueous extracts, respectively, whereas it was 32.5 ± 6.8 μg/ml for tartar emetic. The results indicated that the methanolic extract was more effective than aqueous extract, although there was no significant difference. The extracts were less effective as compared to the control drug. Further investigation is required to evaluate these extracts on clinical stage in macrophage-amastigote model.