Comparative effect of antiinflammatory drugs on rat paw edema induced by human sterile dental plaque extract, carrageenan or dextran.

The effect of antihistamine (diphenhydramine) or antihistamine and antiserotonin (cyproheptadine) or aspirin-like (acetylsalicylic acid and indomethacin) or corticosteroid (dexamethasone) drugs on the edema induced by various doses of carrageenan, dextran or human sterile dental plaque extract, injected intraplantarily in the rat paw were comparatively studied. The results showed that: (a) human dental plaque extract injected into the rat paw induces a dose-dependent inflammatory response, confirming that it is a potent phlogistic agent; (b) the edema induced by the plaque extract though closer to the pattern of carrageenan-induced edema, was different to both the carrageenan- and the dextran-induced edema in its time course and the response to antiedema drugs; (c) histamine and serotonin are liberated in the plaque-induced edema but they play no essential role; (d) the inhibitors of arachidonic acid metabolite formation (ASA, indomethacin and dexamethasone) inhibit this inflammation suggesting the presence of prostaglandin-like substances since its first phase.