Inhibition of prostaglandin E synthesis by steroidal and nonsteroidal antiinflammatory drugs in human synovial fibroblast cultures.

Human synovial fibroblasts were "activated" by poly (I) X poly (C) to overproduce prostaglandin E (PGE). Hydrocortisone, diclofenac, indomethacin and ibuprofen inhibited PGE production in a dose dependent manner. Diclofenac (0.2 microgram/ml) had an effect similar to that of 1 microgram/ml of indomethacin and a stronger one than that of 0.5 microgram/ml hydrocortisone and 0.2 microgram/ml ibuprofen. Addition of hydrocortisone with either indomethacin or diclofenac had a synergistic inhibitory effect on PGE production. We suggest that this is an additional model for the study of PGE effect of antirheumatic drugs.