FIG. 4.

Dexra limited DXR's cytotoxicity in KK-15 cells. The fraction of viable cells was measured using the ATP-based CellTiter-Glo assay 24 h postdrug treatment. The graph depicts summary of four experiments (± SEM). The cells were pretreated for 1 h with Dexra or DMSO followed by the addition of DXR to the media already containing Dexra or DMSO. The presence of Dexra shifted the LD₂₀ for 24-h exposure to DXR 5- to 8-fold for all Dexra doses tested (P < 0.01, two-way ANOVA). The maximum shift was seen with 10 μM Dexra, but there was no statistically significant difference between the protective effect across the Dexra doses (two-way ANOVA, P > 0.05).