Lutein interferes with PDGF binding to VSMCs. (A) PDGF was preincubated with vehicle (control) or lutein for the indicated time and was added to stimulate cells for 10 min. Cells were then harvested and lysates were analyzed by Western blotting (n = 3). (B) Flowcytometric analysis of PDGF binding to VSMCs. Fluorescein-labeled soybean trypsin inhibitor (basal) or PDGF were added to VSMCs in the presence of DMSO (control), lutein (5 and 10 μM), or anti-PDGF blocking Ab at 4°C for 1 h, cells were analyzed by flowcytometry. The representative histograms and quantitative data were shown (n = 3-4).