Plant-derived compounds in treatment of leishmaniasis.

Leishmaniasis is a neglected public health problem caused by the protozoan species belonging to the genus Leishmania affecting mostly the poor populations of developing countries. The causative organism is transmitted by female sandflies. Cutaneous, mucocutaneous, and visceral clinical manifestations are the most frequent forms of leishmaniasis. Chemotherapy still relies on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosin and liposomal amphotericin B. However, the application of these drugs is limited due to low efficacy, life-threatening side effects, high toxicity, induction of parasite resistance, length of treatment and high cost. Given the fact that antileishmanial vaccines may not become available in the near future, the search for better drugs should be continued. Natural products may offer an unlimited source of chemical diversity to identify new drug modules. New medicines should be less toxic or non-toxic, safe, more efficient, less expensive and readily available antileishmanial agents, especially for low-income populations. In the present review, special focus is on medicinal plants used against leishmanaiasis. The bioactive phytocompounds present in the plant derivatives including the crude extracts, essential oils, and other useful compounds can be a good source for discovering and producing new antileishmanial medicines.