Current state of the art of gold complexes as antileishmanial agents

In regard to the number of deaths caused by parasitic diseases, leishmaniasis occupies the sad second position in the world. This infectious disease is strongly influenced by environmental changes and socio-economic factors. No human vaccine is available and the only option for treating infected people is first-line chemotherapy. Only few drugs can be used for this because most drugs are too toxic and parasites develop drug resistances. Therefore, new efficient antileishmanial drugs are strongly needed. Gold compounds applications in medicine have a long history and the biomedical effects of metal-organic gold compounds as well as the repurposing of the anti-rheumatic drug Auranofin in cancer have prompted researchers to develop new potential drugs for major human medical diseases, including recently leishmaniasis. This review covers the current situation in regard to the design of Au(I) and Au(III) complexes for antileishmanial applications on the basis of in vitro results and toxicity assessment and rare in vivo results. The mechanistic and theoretical studies available are mainly focused on the trypanothione redox system, very specific for this parasite, by analogy with the thioredoxin system in mammalians, considered as one of the principal targets of gold compounds in anticancer studies. • Leishmaniasis is the second deadliest parasitic disease worldwide. • Endemic in tropical regions, Leishmaniasis could spread to rich countries due to climate change. • Comprehensive overview of gold antileishmanial agents containing ligands of interest. • Detailed overview of in vitro and in vivo antileishmanial potency with emphasis on toxicity. • Insights into the possible mechanisms of action against key parasite targets at the molecular level.