Latest developments in the diagnosis, prevention, and treatment
Permanent solution for the leishmaniasis in terms of successful human vaccination is still a major challenge. However, there are different vaccinations currently being tested in mouse model.
One of them uses “killed but metabolically active” parasites to induce host immune system reaction. Mice infected by “killed but metabolically active” L. infantum chagasi showed no signs of organomegaly or parasite presence 6 months after infection compared to mice infected with live parasite. Finally “killed but metabolically active” L. infantum chagasi has also shown to induce parasite-specific protective host immune response that is similar to response induced by live Leishmania [56].Using salivary peptides of the sandfly holds potential to be used as a vaccine component; however, complex immune response makes it a challenge. Novel drug combinations have been tested in some endemic regions in order to lower the treatment cost and toxicity and preventing resistance gain by the parasite. Nitroquinolines were found to show leishmanicidal activity. Antimicrobial peptides including dermaseptin, andropin, and cecropin have been found effective against CL. Edelfosine is an oral drug with greatly increased activity compared to miltefo- sine. There are also compounds isolated from plants which are tested and observed to have antileishmanial activity. For example, a polyphenolic flavanoid, quercetin, has shown antileishmanial activity in treatment of VL [57]. Four plant species named Agave americana, Azadirachta indica, Eclipta alba, and Piper longum showed important antileishmanial activity too [58—61].
Macrophage targeted drug delivery system is another novel approach to directly effect Leishmania parasites that live in the macrophages as their infection mechanism. As getting into macrophages is a challenge, liposomes, microspheres, nanoparticles, and carbon nanotubes are some of the various drug carriers that are studied to target macrophages [62]. In addition, use of specific receptors expressed by macrophages to actively deliver a drug is also used [63].
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