Figure 3.

Localization of intracellular curcumin at the endoplasmic reticulum (ER) and associated signaling events. (a,b)—Confocal analysis of the double staining with curcumin (in green) and ER-tracker red, (in red). Arrows indicate the ER compartment; (c,d) panels are enlargements of the two boxes numbered 1 and 2 of pictures (a,b). (e)—Volume of the ER compartment assayed by the ER tracker red fluorescence in flow cytometry with different concentrations of curcumin with or without the ER stress inhibitor 4-phenylbutyric acid (PBA); (f)—Ca²⁺-ATPase measurements illustrating SERCA inhibition by different curcumin concentrations; (g)—Histogram representation of CHOP and GRP78 measurements following incubation with different curcumin concentrations illustrating the UPR response; (h)—Flow cytometry analysis of curcumin and calcium contents over time (in hours), by curcumin autofluorescence and Fluo4-AM, respectively.