Inhibitory effect of 2-(2-fluoro-4-biphenylyl) propionic acid (Flurbiprofen) on prostaglandin synthesis

Inhibitory effects cf 2-(2-fluoro-4-biphenylyl) propionic acid (Flurbiprofen, FP-70) on prostaglandin (PG) synthesis and PG activity were investigated both in vivo and in vitro. FP-70 at 0.64 μM showed 50% inhibitory effect on PG synthesis from arachidonic acid in cell-free homogenate of guinea pig lung. PGE2 and PGF2α in the sample of lung homogenate incubated with arachidonic acid were separated by thin-layer chromatography in solvent AI system. FP-70 inhibited strongly both synthesis of PGE2 and PGF2α, at 3 μM, but inhibited more extensively the synthesis of PGE2 than that of PGF2α at 0.3 μM. FP-70 at 1 mg/kg, p.o. inhibited mostly arachidonic acid potentiation of carrageenin-induced edema in the rat paw, but did not inhibit PGE2 potentiation of carrageenin-induced edema. FP-70 also did not inhibit the contraction of rat stomach strip induced by PGE2. From the above and previously5) reported results, FP-70 proved to inhibit PG synthesis but not PG activity. It is suggested that the potent anti-inflammatory action of FP-70 is the result of inhibition of PG synthesis.