Plasmodium falciparum : effect of Solanum nudum steroids on thiol contents and beta-hematin formation in parasitized erythrocytes Pabon, A. /Deharo, Eric Zuluaga, L. Maya, J. D. Saez, J. Blair, S. Solanum nudum Plasmodium falciparum Glutathione Cysteine beta-Hematin 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. 2009 text https://www.documentation.ird.fr/hor/fdi:010046212 fdi:010046212 Pabon A., Deharo Eric, Zuluaga L., Maya J. D., Saez J., Blair S.. Plasmodium falciparum : effect of Solanum nudum steroids on thiol contents and beta-hematin formation in parasitized erythrocytes. 2009, 122 (4), 273-279 EN