Background: Cutaneous leishmaniasis is an endemic disease in some parts of Iran. The use of pentavalent antimony compounds as first therapeutic choice is associated with limitations and several adverse effects and complications. This study aimed to evaluate the effect of aloe-emodin on Leishmania major promastigote growth in vitro conditions and also the effect of aloe-emodin on induction of apoptosis in Leishmania major promastigotes.

Materials and Methods: In this experimental study, different concentrations (40, 80, 120 and 160 µg/ml) of aloe-emodin were tested in three different times (24, 48 and 72h) on Leishmania promastigotes and the IC50 was calculated by counting the number of parasites. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to determine the percentage of live promastigotes after adding aloe-emodin. Apoptosis at three different concentrations (40, 80 and 120 µg/ml) was evaluated by flowcytometry and also the percentages of early and late apoptosis and necrosis were determined.

Results: Result showed that aloe-emodin has an inhibitory effect on the growth of Leishmania promastigotes. The IC50 value was 52.79µg/ml. Moreover, the results of flowcytometry showed that aloe-emodin induced the early and late apoptosis in Leishmania promastigotes.

Conclusion: Aloe-emodin shows an antileishmanial effects in vitro condition and regarding its herbal origin, it can be tested as the new drug in vivo studies.