Figure 4.

CsA inhibited DMF-induced cell death. (A, B) CsA inhibited DMF-induced cell death in CT26 and HT29 cells as indicated by using live/dead assay. MMF and methanol did not induce cell death. The live cells appear as green and dead cells as red. (A) The number of cells counted: 7833, 1921, 6826, 1123, 14381 and 12381 in control, DMF (100 μM), DMF (200 μM), DMF (100 μM) + CsA (1 μM), MMF (200 μM) and methanol (200 μM) respectively. (B) The number of cells counted: 4592, 4038, 5429, 1189, 4756 and 3568 in control, DMF (100 μM), DMF (100 μM) + CsA (1 μM), DMF (100 μM) + CsA (5 μM), MMF (200 μM) and methanol (200 μM) respectively. Cells were pretreated with CsA for 30 min, then treated with both DMF and CsA for 24 h. χ² test was used, **P < 0.01 versus control; ##P < 0.01 versus DMF. (C) CsA treatment attenuated DMF-induced mitochondrial membrane depolarization in CT26 cells, evaluated by JC-1 staining. In normal conditions, JC-1 accumulated in the mitochondrial matrix to form J-aggregates, which fluoresced red and indicated a high MMP. When cell MMP was low, JC-1 would not accumulate in the mitochondrial matrix and exists in its monomer form, which fluoresced green.