Figure 9. Curcumin does not Cause Mitochondrial Inner Membrane Depolarization.

Fibroblasts were treated with 25 µM curcumin or were left untreated. After 24 hours, cells were labeled for 30 minutes with 0.1 µM of the fluorescent dye tetramethylrhodamine ethyl ester (TMRE), which accumulates in mitochondria. As a negative control cells were not labeled. To check if the cells were correctly labeled the protonophore FCCP was added, which causes mitochondrial membrane depolarization. Fluorescence was determined using flow cytometry using channel FL2. Grey peak = untreated cells, thick black line = 25 µM curcumin, thin black line = FCCP treatment of untreated TMRE-labeled cells, dashed line = unlabelled cells. M1 represent negatively labeled cells, M2 represents positively labeled cells.