Topical morphine for the treatment of cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) is a potentially disfiguring parasitic disease which is endemic in many parts of the world. The evidence for optimal treatment of CL is uncongenial. The development of a compound used for the topical treatment of CL is an attractive option for overcoming the problems of toxic and expensive currently used anti-leishmanial drugs. Easy application is another attraction of topical treatment compared to systemic therapy. Evidence is certainly about a variety of immune responses in the healing process of CL. The immune modulatory effect of morphine also has been known in clinical medicine for decades. Protection against leishmaniasis is dependent upon generation of CD4(+) helper T-cells immune response. There are some evidences that opioids could be members of the cytokine family and the regulation of immune and inflammatory responses is dependent on the functions of cytokines; therefore much effort should be placed on understanding the effect of morphine on cytokine activity. Based on a previous mentioned evidence we suggest that morphine as an immunomodulator could induce the healing process of cutaneous leishmaniasis through inducing the release of a number of cytokines.