Figure 2: Transport characteristics of genistein, DHG, daidzein, and DHDacross Caco-2 cell monolayers in the presence (●) and absence (○) of a proton gradient. Permeations of 50 μM genistein, DHG, daidzein, and DHD from the apical side to the basolateral side were measured at 37°C in the presence (●) and absence (○) of a proton gradient (apical pH, 6.0 or 7.4; basolateral pH, 7.4). Each point represents the mean ± S.D of three experiments.DHG, dihydrogenistein; DHD, dihydrodaidzein.