Inhibition of cTXNPx by chalcone impairs the enzyme antioxidant effect in the parasite.
L. amazonensis promastigotes (1 x 106/mL) were incubated with compounds 1c or 3 at the indicated concentrations for 48 h, during which the numbers of cells were recorded. Then, 4 x 105 cells were transferred to black 96 well plates for fluorimetric assessment of ROS production with H2DCFDA (20 μM) for 30 min. (a-b) Parasite killing (dotted lines) and ROS production (continuous lines) induced by 1c (a) 3 (b). BMDM (1 x 105/well) infected or not with L. amazonensis promastigotes (10:1) for 72 h on 96 well-plate, then cells were incubated with 1c or 3 (0.07, 0.7 and 7.0 μM) for 1 h at 37°C and ROS production measured as described for promastigotes. (c) ROS production on infected macrophages. (d) ROS production on uninfected macrophages. Means ± SD (n = 3). * p<0.05 in relation to untreated cells.