1.Screening Of COX-2 Selective Inhibitor And In Vivo Study On Its Anti-inflammatory Effects 2.Study Of Cyclooxygenase Inhibitors On Mononuclear Cells Differentiation And Its Mechanism Of Action

Cyclooxygenase (COX) is one of the key enzymes in arachidonic acid metabolism pathway. There are at least two COX isoforms: COX-1 and COX-2. COX-1 is constitutively expressed in most tissues, while COX-2 is usually absent but can be induced by many stimuli in local tissues. It is proved that COX-2 is closely related to inflammation, arthritis, febrile response, hyperalgesia, tumor and alzheimer's diseases. COX-2 selective inhibitors showed effective inhibition of inflammations while safer profiles on gastric intestinal side effects.In this research, an in vitro COX-1 and COX-2 assay system based on mice peritoneal macrophages utilizing endogenous arachidonic acid was estblished, which could evaluate both COX-1 and COX-2 activities of compounds in same cell and appropriate for in vitro evaluation and structure-activity relationship analysis of COX inhibitors. A23187 could induce 6-keto-PGF_1α productions of mice peritoneal macrophages in a dosage-dependent manner. The concentrations of 6-keto-PGF_1α in supernatants could represent COX-1 activity. LPS could induce PGF₂ productions of mice peritoneal macrophages in a dosage-dependent and time-dependent manner. The accumulation of COX-2 mRNA is correlated with PGE2 production. The concentrations of PGE2 in supernatants could represent COX-2 activity. In COX-1 assay, indomethacin could inhibit COX-1 activity with IC50 of 4.73 ± 1.09 nmol/L. Rofecoxib only achieved its maximum inhibitory effect (17.2%) at the concentration of 10^-6mol/L. In COX-2 assay, rofecoxib and indomethacin exhibit comparable inhibition on COX-2 with IC₅₀ of 4.69 + 0.48 nmol/L å’Œ 7.11 ± 1.20nmol/L respectively. The IC₅₀(COX-1) / IC₅₀(COX-2) ratio of rofecoxib and indomethacin were 0.67 and 213 respectively. These data were in line with other published literatures. We evaluated the inhibitory effects of 43 candidate compounds on COX-1 and COX-2 using this assay system and obtained IC₅₀ value of 32 compounds. Concerning the activity data of 17 3,4-diaryl-3-pyrrolin-2-ones derivatives in 2 series, most compounds in series II exhibited comparable inhibitory effects with rofecoxib on COX-2, some of them also have high selectivity. While most compounds in series I exhibited less activities than those of series II. Primary structure-activity analysis revealed that the relative position of the sulfonylphenyl...