Fig. 4.

Concentration-dependent inhibition of COX-2 protein expression and PGE₂ release by SD0006 in a human RASF cell line in response to IL-1β. a Dose-dependent inhibition of PGE₂ release. IC₅₀ determinations were made using Grafit 5(2) software with data from two experiments. Inhibitor was added 1 h before stimulation with 1 ng/ml IL-1β, then after 20 h supernatants were removed and assayed for PGE₂ as described in Materials and Methods. b Western blots demonstrating selective inhibition of COX-2 protein expression compared with COX-1. Cells were treated as in a but collected after 4 h of stimulation.