Leishmaniasis is a parasitic zoonosis transmitted by arthropods, which is addressed as a public health problem in tropical and subtropical countries. Based on clinical symptoms in patients, there are three forms of cutaneous, visceral (kala-azar) and mucocutaneous leishmaniasis (spondia).Endemic cutaneous and visceral leishmaniasis in Iran is among the most important health problems, causing numerous annual losses in the society. According to WHO reports, it is estimated that there are 12 million cases of cutaneous leishmaniasis in 88 countries worldwide, and 350 million individuals are at risk for this disease. The average incidence of cutaneous leishmaniasis in Iran is 0.28 per one thousand population. Annually, approximately 20,000 new cases of cutaneous leishmaniasis are reported from different parts of Iran, and the actual incidence is estimated to be several times the reported estimates. Sandflies from Psychodidae family are vectors of leishmaniasis, with promastigotes and amastigotes as visible forms of the parasite. Flagellated form (promastigote) of leishmaniasis, which is the causative agent of leishmaniasis, is transmitted to vertebrate hosts including humans by infected sandfly bite, and is converted to the immobile form without flagellum in mononuclear phagocytic cells.
The defensive mechanism of the body to control intracellular parasite of leishmania is dependent upon Th1 cell function. These cells activate macrophages to secrete large amounts of cytokines, which play essential roles in the increased activity of immune cells. Macrophages play an important role in the initiation and regulation of immune responses in the body and in culture medium. Promastigotes slowly enter macrophages to cause a primary infection and evade the host immune response depending on the presence of resident macrophages, and reactivate the intracellular infections (amastigotes). The host responds to this reaction by nonspecific (innate) and acquired (cellular immunity and delayed hypersensitivity) immune mechanisms. Under favorable conditions, the macrophages extensively destroy leishmania parasites under the guidance of T-Helper cells.
In the past 65 Year, leishmaniasis has been mainly treated using antimony compounds. The first-line treatment for leishmaniasis includes amphotericin B, meglumine antimonate (Glucantime) and sodium gluconate (Pentostam). These compounds prevent the production of adenosine triphosphate by affecting the parasite enzymes, especially phosphokinase.
Due to repeated injections and high doses, which lead to side effects such as liver, cardiovascular and biochemical complications, these drugs also impose economic costs on families. In addition, these compounds have limitations such as lack of effect in oral ingestion, long-term treatment and lack of treatment response in nearly 10-15% of the cases.
One of the main problems in treatment of leishmaniasis in endemic countries is improper use of these compounds, resulting in...