Effects of SOD, L-NAME, epicatechin and FeTTPs on oxLDL-induced apoptosis in wild-type EPC. EPC cultures were exposed to nLDL (10 μg/ml) or oxLDL (10 μg/ml), or oxLDL (10 μg/ml) in the presence of SOD (100 U/ml), L-NAME (0.5 mM), epicatechin (100 μM) or FeTPPs (2.5 μM) in serum-free medium. A control well was treated with serum-free medium alone. Apoptosis was determined by TUNEL staining. Data are expressed as the percentage of TUNEL positive cells with respect to the total number of cells (DAPI staining) per high power field. Data are presented as mean ± SD, n = 3; + p < 0.05 oxLDL versus nLDL or control; * p < 0.05 versus oxLDL.