Figure 3: Effects of quercetin on cell proliferation and insulin secretion in INS-1 β-cells with or without 1 mM fructose treatment. INS-1 β-cells were treated with 5–100 μM quercetin in the absence or presence of 1 mM fructose from 24 h. Data were presented as the mean ± SEM of three to six independent experiments. # , ## , and ### relative to control cells without fructose and quercetin treatment; * and ** relative to vehicle cells only with fructose treatment.