Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Experimental Parasitology 273-279 Solanum nudum Plasmodium falciparum Glutathione Cysteine beta-Hematin 2009 fdi:010046212 ENG Experimental Parasitology 0014-4894 ISI:000267636400003 4 10.1016/j.exppara.2009.04.014 https://www.documentation.ird.fr/hor/fdi:010046212 https://www.documentation.ird.fr/intranet/publi/2009/07/010046212.pdf 122 Horizon (IRD) We studied the effects on total thiols glutathione (GSH) and cysteine contents in Plasmodium falciparum in vitro when treated with four steroid derivatives and a sapogenin (Diosgenone) extracted from Solanum nudum. We also determined their capacity to inhibit beta-hematin formation. We showed that SN-1 (16 alpha-acetoxy-26-hydroxycholest-4-ene-3,22-dione) increased total glutathione and cysteine concentrations while SN-4 (26-O-beta-D-glucopyranosyloxy-16 alpha-acetoxycholest-4-ene-3,22-dione) decreased the concentration of both thiols. Acetylation in C16 was crucial for the effect of SN-1 while type furostanol and terminal glucosidation were necessary for the inhibitory properties of SN-4. The combination of steroids and buthionine sulfoximine, a specific inhibitor of a step-limiting enzyme in GSH synthesis, did not modify the glutathione contents. Finally, we found that SN-1 inhibited more than 80% of beta-hematin formation while the other steroids did not show any effect. 052 UR152 Chili / Colombie