In vitro and in vivo activities of Peganum harmala extract against Leishmania major.

Background: In vitro and in vivo antileishmanial activities of crude hydroalcoholic extract of peganum harmala seeds were investigated against Leishmania major.

Methods: The extract of aerial parts of P harmala was obtained by maceration. The in vitro experiments were performed on promastigotes to assess antileishmanial activity of the extract using amphotericin B as a reference. The in vivo studies were carried out on cutaneous leishmaniasis in outbred mice to evaluate the effects of topical application of the ointment-based extract.

Results: The in vitro experiments showed a concentration-dependent decrease of parasites number caused by the extract with an IC50 value of 59.4 μg/ml. In vivo studies demonstrated a significant post-treatment decrease in the lesion size and parasite count in infected animals, compared to placebo and control groups. High performance liquid chromatography (HPLC) of the crude extract demonstrated the existence of harmaline and harmine as beta-carboline alkaloids.

Conclusions: P harmala seeds extract showed significant in vitro and in vivo antileishmanial activities. Most biological activity of the extract could be attributed to its beta-carboline content. However, another alkaloid of P harmala seeds extract, peganine, has also been reported to have antileishmanial activity. These beneficial effects can be attributed to the cumulative effects of various biologically active components present in it.