Novel azasterols as potential agents for treatment of leishmaniasis and trypanosomiasis.
This paper describes the design and evaluation of novel azasterols as potential compounds for the treatment of leishmaniasis and other diseases caused by trypanosomatid parasites. Azasterols are a known class of (S)-adenosyl-L-methionine: Delta24-sterol methyltransferase(24-SMT) inhibitors in fungi, plants, and some parasitic protozoa. The compounds prepared showed activity at micromolar and nanomolar concentrations when tested against Leishmania spp. and Trypanosoma spp. The enzymatic and sterol composition studies indicated that the most active compounds acted by inhibiting 24-SMT. The role of the free hydroxyl group at position 3 of the sterol nucleus was also probed. When an acetate was attached to the 3beta-OH, the compounds did not inhibit the enzyme but had an effect on parasite growth and the levels of sterols in the parasite, suggesting that the acetate group was removed in the organism. Thus, an acetate group on the 3beta-OH may have application as a prodrug. However, there may be an additional mode(s) of action for these acetate derivatives. These compounds were shown to have ultrastructural effects on Leishmania amazonensis promastigote membranes, including the plasma membrane, the mitochondrial membrane, and the endoplasmic reticulum. The compounds were also found to be active against the bloodstream form (trypomastigotes) of Trypanosoma brucei rhodesiense, a causative agent of African trypanosomiasis.
Welsh School of Pharmacy, Cardiff University, Cardiff, CF10 3XF, United Kingdom.
Silvia Orenes
SO
Lorente
Juliany C F
JC
Rodrigues
Carmen
C
Jiménez Jiménez
Miranda
M
Joyce-Menekse
Carlos
C
Rodrigues
Simon L
SL
Croft
Vanessa
V
Yardley
Kate
K
de Luca-Fradley
Luis M
LM
Ruiz-Pérez
Julio
J
Urbina
Wanderley
W
de Souza
Dolores
D
González Pacanowska
Ian H
IH
Gilbert
D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D006801:Humans; D007624:KB Cells; D007893:Leishmania donovani / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D018320:Leishmania major / Q000187:drug effects; D007894:Leishmania mexicana / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D007896:Leishmaniasis / Q000188:drug therapy* / Q000469:parasitology; D008055:Lipids / Q000737:chemistry; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D008854:Microscopy, Electron; D013261:Sterols / Q000378:metabolism; D013329:Structure-Activity Relationship; D014344:Trypanocidal Agents / Q000494:pharmacology*; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D014352:Trypanosomiasis / Q000188:drug therapy* / Q000469:parasitology
D000981:Antiprotozoal Agents; D001372:Aza Compounds; D008055:Lipids; D013261:Sterols; D014344:Trypanocidal Agents; D008780:Methyltransferases; C022670:delta 24-sterol methyltransferase