The effect of alpha-(3,5-di-t-butyl-4-hydroxybenzylidene)-gamma-butyrolactone (KME-4), a new anti-inflammatory drug, on leucocyte migration in rat carrageenan pleurisy.

KME-4,alpha-(3,5-di-t-butyl-4-hydroxybenzylidene)-gamma-buty rolactone was found to reduce the accumulation of leucocytes and exudate volume in the rat carrageenan pleurisy model. When administered orally 1 h before carrageenan, KME-4 (3-10 mg kg-1) induced a degree of inhibition of leucocyte migration almost equal to that of indomethacin (3-10 mg kg-1) in both 5 h and 24 h pleurisies. Furthermore, KME-4, when administered orally 5 h after the carrageenan, inhibited both monocyte numbers and exudate volume in a 24 h pleurisy and was more effective than indomethacin and BW755c which inhibited only monocyte migration. These results suggest that KME-4 has a differential anti-inflammatory activity. Dexamethasone (0.25 mg kg-1) showed strong inhibition of total cell numbers and exudate volume.