The effect of cicerfuran, an arylbenzofuran from Cicer bijugum, and related benzofurans and stilbenes on Leishmania aethiopica, L-tropica and L-major

The effect of 3 arylbenzofurans and 7 stilbenes on the growth of Leishmania parasites and human monocytes was evaluated. Promastigotes from cultures of L. aethiopica, L. major and L. tropica were tested in the exponential phase of growth. All compounds were active at concentrations of 100 mu g/mL within 6 hours. The 2-hydroxylstibene showed activity at a concentration < 1 mu g/mL, with an LD50 of 3-5 mu g/mL after 48 hours of incubation. The most active compounds: cicerfuran, 2-hydroxy-2'-methyl-4,5-methylenedioxystilbene, 2-hydroxy-2 -methoxy-4,5-methylenedioxystilbene and 2-hydroxystilbene had even stronger activity against the temperature-induced amastigotes of L. aethiopica, with the latter having the highest relative potency against all three species. Leishmanicidal activity seemed to be associated with the level of oxygen substitution in each compound. The ratio between leishmanicidal activity on promastigotes and toxicity to human cells suggested that the compounds could be considered as leishmanicidal drug leads.