Leishmaniasis is a
neglected disease affecting more than 12 million people worldwide. The most used drugs are pentavalent antimonials that are very toxic and display the problem of drug resistance, especially in endemic regions such as Bihar in India. For this reason, it is urgent to find new and less toxic drugs against
leishmaniasis. To this end, the understanding of pathways affecting parasite survival is of prime importance for targeted
drug discovery. The parasite survival inside the macrophage is strongly dependent on
polyamine metabolism.
Polyamines are, in fact, very important for cell growth and proliferation. In particular,
spermidine (Spd), the final product of the
polyamine biosynthesis pathway, serves as a precursor for
trypanothione (N1,N8- bis(glutathionyl)
spermidine, T(SH)2) and
hypusine (N(ε)-(4-amino-2-hydroxybutyl)lysine). T(SH)2 is a key molecule for parasite defense against the
hydrogen peroxide produced by macrophages during the
infection. Hypusination is a posttranslational modification occurring exclusively in the eukaryotic
initiation factor 5A (eIF5A), which has an important role in avoiding the ribosome stalling during the biosynthesis of
protein containing polyprolines sequences. The
enzymes, belonging to the
spermidine metabolism, i.e.
arginase (ARG),
ornithine decarboxylase (ODC),
S-adenosylmethionine decarboxylase (AdoMetDC),
spermidine synthase (SpdS),
trypanothione synthetase (TryS or
TSA),
trypanothione reductase (TryR or TR),
tryparedoxin peroxidase (TXNPx),
deoxyhypusine synthase (DHS) and
deoxyhypusine hydroxylase (DOHH) are promising targets for the development of new drugs against
leishmaniasis. This minireview furnishes a picture of the structural, functional and inhibition studies on
polyamine metabolism
enzymes that could guide the discovery of new drugs against
leishmaniasis.