Figure 4. Xaliproden suppresses the secretion of IL-1β from cells induced with TNF-α. ARPE-19 cells were seeded at 70% confluency and grown overnight. They were incubated in serum-free media for 3 h followed by the addition of 10 ng/ml of tumor necrosis factor-α (TNF-α) or TNF-α plus 20 µM xaliproden, and the cells were grown for 15 h. Supernatants were harvested and used for quantitation of interleukin (IL)-1β in with enzyme-linked immunosorbent assay (ELISA). Bars represent the average of triplicates ± standard deviation (SD). *, p = 0.008. xal = xaliproden.