Figure 5.

Spectrofluorometric evaluation of the store-operated calcium entry (SOCE) mechanism. Synchronized P. falciparum 3D7 in the trophozoite stage (28–32 h) were labeled with Ca²⁺ Fluo-4/AM probe. (A) The parasites were previously incubated with DMSO solvent (0.01%). (B) The parasites were previously treated with MMV665831 compound (1 μM). After 15 min of treatment, parasites at 10⁷ cells/ml were placed in free Ca²⁺ buffer. Thapsigargin (Thg; 5 μM) was used to deplete the Ca²⁺ from the endoplasmic reticulum (ER). CaCl₂ (2 mM) was added and the increase in the [Ca²⁺]cyt was monitored. (C) Representative curve for SOCE measurement at the control and MMV665831 treated parasites. (D) F0 corresponds to the mean of the fluorescence obtained between 140 and 150 s, and F1 corresponds to the mean of the fluorescence obtained between 290 and 300 s. (E) F0 corresponds to the mean of the fluorescence obtained between 50 and 60 s, and F1 corresponds to the mean of the fluorescence obtained between 140 and 150 s. Three independent experiments were performed in triplicates. ^*Represents significant difference found by Student’s t-test (^*p ≤ 0.05).