Novel concepts in the mode of action of anti-inflammatory steroids

Since the discovery that cortisone could be used as an anti-inflammatory agent, this compound and synthetic anti-inflammatory steroids have been widely used in all inflammatory and allergic diseases. Anti-inflammatory steroids have been reported to act on almost all steps of the inflammatory reaction. Nevertheless their molecular mechanism of action has remained poorly understood, in opposition to non steroidal anti-inflammatory drugs whose mechanism is now well known. We report here recent data concerning their molecular mechanism of action. These recent results have all led to the conclusion that part of their action can be explained by the synthesis "de novo" of one or more proteins which then will inhibit the deacylation of arachidonic acid from membrane phospholipids. Whether the action of this or these proteins can explain all the known anti-inflammatory actions of steroids remains to be investigated.