Fig. 6

Mid- and long-term effects of ML304 on the redox ratio of P. falciparum 3D7^{[hGrx1-roGFP2]} parasites. Plasmodium falciparum cells were treated with ML304 at 1 µM, 50 µM, and 100 µM for 4 h (a). For 24 h incubations (b), cells were treated with ML304 at 1 µM, 5 µM, and 10 µM. The anti-malarial drugs ATS and CQ were also tested in both 4 h and 24 h experiments for comparison. Free thiols were subsequently blocked with 2 mM NEM. Both 4 h and 24 h incubations of 3D7^{[hGrx1–roGFP2]} parasites with ML304 showed significant increases in the 405/488 nm fluorescence ratio using CLSM. Non-treated parasites served as controls. All experiments included fully oxidized (1 mM DIA) and fully reduced (10 mM DTT) parasites (each using 2 min incubations) prior to blocking with NEM. CLSM data was obtained from 10 to 20 trophozoites for each experiment and each incubation time. Mean values and standard errors of the means (± SEM) are shown for three independent experiments. A one-way ANOVA test with 95% confidence intervals with the Dunnett’s multiple comparison test was applied for statistical analysis of significance (*p < 0.05; **p < 0.01; ***p < 0.001) and indicated significant changes compared to the respective control