Abstract

Leishmaniasis is a complex protozoan disease comprising a wide range of clinical manifestations that is usually divided into visceral leishmaniasis, cutaneous leishmaniasis, and muco-cutaneous leishmaniasis depending on leishmania parasite species and host's immune system responses. Most of the drugs produced for the treatment of leishmaniasis, from the first used to the most recently accepted, are toxic, resistance issues and poorly tolerated. The purpose of this study is to evaluate the effectiveness of saffron (Crocus sativus) and its apoptotic activity against Leishmania major (MRHO/IR/ 75/ER) promastigotes. MTT assay was used to find viability of L. major promastigotes and the achieved results were explicated as IC₅₀ (50% inhibitory concentration). ED₅₀ (50% effective doses) for L. major amastigotes were also analyzed. Annexin-V FLUOS staining was performed to study the cell death properties of saffron by using FACS analysis. Qualitative analysis of the DNA fragmentations was accomplished by agarose gel electrophoresis and light microscopy was used to observe morphological changes of promastigotes. Our results revealed that L. major promastigotes and amastigotes are sensitive to saffron at different concentrations and time dependent manner with apoptotic features including DNA laddering, cytoplasmic shrinkage, and externalization of phosphatidylserine. IC₅₀ and ED₅₀ of this extract after 48 h of incubation was 0.7mg/ml and 0.5 mg/ml respectively. Finally, C. sativus has shown anti-leishmanial activity against L. major promastigote and amastigote and may induce apoptosis.

Keywords: Cell death, Crocus sativus, Leishmania major, saffron.