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

Human synovial fibroblasts were 'activated' by poly(I) · poly (C) to overproduce prostaglandin E (PGE). Hydrocortisone, diclofenac, indomethacin and ibuprofen inhibited PGE production in a dose dependent manner. Diclofenac (0.2 μg/ml) had an effect similar to that of 1 μg/ml of indomethacin and a stronger one than that of 0.5 μg/ml hydrocortisone and 0.2 μg/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.