Fig. 6.

Effects of the small interfering RNA inhibition of SR-BI expression on the cellular uptake of β-C (b-C) and ZEA in ARPE-19 cells. A: Immunoblots of SR-BI expression (using 25 μg total protein/well) in cells treated under the following conditions: lane 1, scrambled RNA interference (RNAi); lane 2, Lipofectamine 2000 (LP2000) only; lane 3, RNAi_1850. The first lane represents protein standards (MagicMark XP Standard from 60 to 220 kDa). B: Cellular uptake of carotenoids (expressed as percentage of control cells treated with LP2000 only) after incubation of 7 week differentiated cells with a carotenoid at 2 μM for 1 h at 72 h after transfection with a RNAi against SR-BI. Data are means ± SD of three independent experiments for each compound tested. * P < 0.005, ** P < 0.0001 compared with the negative control.