Table 1

Effect of 4HPR on ROS generation in Y79 cells

Mean Fluorescence IntensityRelative Increase
Control0.35  ± 0.081
2.5 μM 4HPR1.30  ± 0.103.7
5 μM 4HPR2.12  ± 0.206.1
10 μM 4HPR2.55  ± 0.257.3
5 μM 4HPR + 10mM NAC0.74  ± 0.102.1
5 μM 4HPR + 25mM NAC0.27  ± 0.030.8
25 mM NAC0.20  ± 0.100.7
10 μM RA0.90  ± 0.102.6

Intracellular ROS elevation was analyzed in 4HPR-treated Y79 cells. 4HPR or all-trans-RA was administered to Y79 cell suspensions at the concentrations indicated for 2 h. Cells treated with 4HPR and with NAC were preincubated with the antioxidant for 80 min before the end of the incubation, 50 μ M H2DCFDA was added to the culture medium, and the cells were washed and analyzed by flow cytometry. Elevation of ROS was analyzed by H2DCFDA green fluorescence emission detected with a Coulter Epics XL flow cytometer (excitation, 488 nm; emission, 530 nm). Treatment with 4HPR clearly elevated ROS production by Y79 cells that was blocked by NAC.