Fig. 5.

i⁶A inhibits superoxide anion production in dHL-60 cells. (A) Basal levels of superoxide anion production in dHL-60 cells are low and further reduced by treatment with 10 or 100 µM i⁶A for 6 h. Data are mean and SE. (B) i⁶A pretreatment inhibited TPA-induced superoxide anion production in a dose-dependent manner (1, 10, or 100 µM for 6 h before 8 μM TPA treatment). Data are mean and SE. (C) TPA-induced superoxide anion production was inhibited by pretreatment with 10 μM i⁶A in a time-dependent manner (1, 2, 6, or 24 h before TPA treatment). dHL-60 cells treated only with TPA were used as control. (D) Butyl⁶A and benzyl⁶A significantly inhibit TPA-induced superoxide oxidative stress. Control: dHL-60 cells treated only with TPA. The line within each box represents the median luminescence value; upper and lower edges of each box represent the 75th and 25th percentile, respectively; upper and lower bars indicate the highest and lowest values less than one interquartile range from the extremes of the box. Normalized RLU: relative luminescence units normalized to the mean value of each experiment. Data are from at least 5 replicates, from two independent experiments. ** P < 0.01, *** P < 0.001.