Figure 3.

Inhibition of PGE₂ production of pure COX-1 (a) and COX-2 (b) by ATK in AA-stimulated MC3T3-E1 cells. Enzyme inhibitor potencies were measured in Tris–HCl buffer (30 mM, pH 8.0) containing glutathione (0.49 mM), adrenaline (1 mM) and haematin (1 μM). One unit of COX and 1 μM sodium arachidonate were used. Pre-incubation with ATK was carried out for 30 min at room temperature. Incubation with sodium arachidonate was performed for 30 min at 37 °C. PGE₂ was measured as described under methods.