Determination of prostaglandin E2 by on-line solid-phase extraction–liquid chromatography with ultraviolet detection for microsomal prostaglandin E2 synthase-1 inhibitor screening

A rapid, robust and selective on-line solid-phase extraction–liquid chromatographic method with ultra-violet detection (on-line SPE-LC-UV) for microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitor screening was developed and validated. Disrupted A549 cells were used as mPGES-1 source and the formation of prostaglandin E2 (PGE2) out of the substrate prostaglandin H2 (PGH2) was determined at 195 nm. Direct on-line sample clean up was achieved by automated column switch (C18 trap column) prior isocratic separation using a C18 analytical column. The on-line SPE-LC-UV method was accurate, precise and reproducible in the range of 71–1763 ng/ml for PGE2 and met the generally accepted criteria for bioanalytical methods. The method was successfully applied to determine the IC50 value of the known mPGES-1 inhibitor NS-398.