FIGURE 6.

Inhibition of ATP-induced cell death by parthenolide and Bay 11-7082-related compounds in NG5 macrophages. A–G, cell death was assayed by measuring the percentages of LDH activity released in culture supernatants of NG5 macrophages (% cytotoxicity) treated with the indicated concentrations of parthenolide (Parth; A), Bay 11-7082 (B), and the indicated Bay 11-7082-related compounds (C–G) for 10 min, followed by ATP (5 mm) for 30 min. Each point represents the average of three experiments (n = 3). H, shown is the LDH activity in culture supernatants of NG5 cells treated with ATP for 1 h. The LDH activity (A₄₉₀ units) was assayed in the presence of DMSO, parthenolide (20 μm), Bay 11-7082 (20 μm), or Bay 11-7085 (20 μm). Note that these drugs did not affect LDH enzymatic activity (H).