Figure 5: Time-course (a) and dose-dependent (b) effects of quercetin on the elevated phosphorylation of Akt in fructose-treated INS-1 β-cells. INS-1 β-cells were treated with 1 mM fructose in the absence or presence of 5, 10, and 20 μM quercetin. Data were presented as the mean ± SEM of three to six independent experiments. ## relative to untreated control cells; ** relative to fructose-treated vehicle cells.