Leishmaniasis is a neglected tropical disease caused by a protozoan parasite of the genus Leishmania, mainly associated with the lack of community hygiene and poverty in the developing countries. Leishmaniasis can be cured but the emergence of drug resistance makes it difficult to completely eradicate the disease. Even after so many years, there is still no vaccine available against leishmaniasis. Therefore, treatment of the disease is mainly dependent on the available therapeutic drugs. However, the current chemotherapeutic drugs have several drawbacks such as high toxicity, less efficacy, high cost and emergence of drug resistance, etc. So, to boost the elimination of disease, development of newer therapeutic agents is imperative. As all this is very well-known, including the current anti-leishmanial drugs with their adverse effects, the authors state that the main objective of this book chapter is to present an overview of the disease, its different clinical forms and the diagnostic tools available for the detection of the disease. Natural sources such as plants and microorganisms have shown great results against Leishmania species over the years, indicating that they may be considered as therapeutic agents. Hereafter, potent investigational drugs obtained from the natural sources such as medicinal plants and microorganisms are also discussed in this book chapter.
Keywords: Amastigotes, Amphotericin B, Cutaneous leishmaniasis, Endophytes, Immunological tests, Kinetoplast, Leishmaniasis, Macroalgae, Miltefosine, Molecular diagnostic methods, Mucocutaneous leishmaniasis, Paromomycin, Pentamidine, Pentavalent antimonials, Post Kala-azar Dermal Leishmaniasis (PKDL), Promastigotes, Secondary metabolites, Serological diagnosis, Visceral leishmaniasis or Kala-azar.