Impact of chromatographic sorbent exposure on the HIF-1 inhibitory activity of Curcuma longa extract. Recombined fractions obtained by passing Cu. longa extract over various media were evaluated at 25 μg mL−1 for their effects on hypoxia- (A) and 1,10-phenanthroline (1,10-phen)-induced (B) HIF-1 activation in a T47D cell-based reporter assay. The chromatography conditions are: i – drying control, ii – HP20SS, iii – Si Gel, iv – diol, and v – Sephadex LH-20. Bars represent average + standard deviation from two independent experiments (n = 4 for i, and n = 6 for ii through v). Data were analyzed by one-way ANOVA with the Bonferroni post hoc test using GraphPad Prism 5.0. Differences between data sets were considered statistically significant when p < 0.05. (* p < 0.05, ** p < 0.01, *** p < 0.001).