Effects of PAF‐antagonists in mouse ear oedema induced by several inflammatory agents

Abstract

Several platelet activating factor (PAF)‐antagonists of different chemical structures were tested in the arachidonic acid‐, tetradecanoylphorbol acetate‐, dithranol‐, and benzoic acid‐induced mouse ear oedema models. Topical application of UR‐10324, UR‐11353, CV‐6209 and WEB‐2086 markedly inhibited ear oedema induced by the four irritants tested, mimicking the profile obtained with dexamethasone. YM‐461 was highly effective only in the dithranol‐induced ear oedema, while BN‐52021 failed to inhibit ear oedema in all models tested. Leukocyte recruitment into the inflamed ears was prevented by PAF‐antagonists, as measured by myeloperoxidase activity in the supernatants of ear homogenates. A relationship between PAF‐antagonist and anti‐inflammatory activities was found in some cases, but other mechanisms cannot be excluded to explain the topical anti‐inflammatory effect of these compounds. Our results suggest that topical formulations containing PAF‐antagonists could be useful in the treatment of some inflammatory skin diseases and provide evidence on the involvement of PAF in these inflammatory processes. 1991 British Pharmacological Society