Quercetin significantly suppresses THP-1 cell adherence to IL-1β-stimulated ARPE-19 cells. ARPE-19 cells were preincubated with quercetin (10, 20 µM), 10 µM U0126, 10 µM SB202190, 10 µM SP600125 or 5 µM Bay 11-7082 for 1 h and then stimulated with 1 ng/mL IL-1β for 24 h. (A,B) A THP-1 monocyte adhesion assay was used to evaluate the physiological function of ICAM-1. The fluorescence intensity represents THP-1 cell adhesion to IL-1β-stimulated ARPE-19 cells, which was quantified using Image J software. The data are expressed as mean ± SD of three independent experiments. #
p < 0.05 versus control cells. * p < 0.05 versus IL-1β-stimulated cells.