HN inhibits Ox-LDL-induced apoptosis in HAECs. Cells were incubated overnight with 0.1 µM HN followed by Ox-LDL treatment for 6 h, fixed, and subjected to TUNEL staining. Nuclei were visualized by DAPI staining and cells were imaged by epifluorescence microscopy. TUNEL-positive cells are shown in green and nuclei in blue. (A) Upper panels: HAECs were treated with Ox-LDL without HN pre-incubation; (lower row) cells pre-treated overnight with HN followed by Ox-LDL incubation. Bar, 100 µm. (B) Quantification of TUNEL staining in cells that were left untreated (Control), or incubated with 50 or 100 µg/mL Ox-LDL, or with 100 µg/mL Ox-LDL after an overnight pre-incubation with HN. All incubations with Ox-LDL were for 6 h.