Effect of anti-inflammatory drugs on pleurisy induced by latex of Calotropis procera in rats.

In present study, we have characterized the inflammation induced by latex of Calotropis procera in the rat pleurisy model and evaluated the effect of various inhibitors of inflammatory mediators. Injection of dried latex (DL) into the pleural cavity elicited an acute inflammatory response characterized by protein rich fluid accumulation and leucocyte (polymorphonuclear cells, and mononuclear cells) infiltration in the pleural cavity. The peak inflammatory response was obtained at 6h when the fluid volume, protein concentration and cell infiltration were maximum. All these parameters were attenuated by phenylbutazone (PBZ), celecoxib, dexamethasone, cyproheptadine and chlorpheniramine. All these drugs were also effective in inhibiting the production of prostaglandin E(2) (PGE(2)). Of all the drugs tested, dexamethasone was most effective in inhibiting DL induced pleurisy. The results clearly indicate that prostaglandins (PGs) and biogenic amines play a key role in the development of pleurisy induced by DL and it serves as a model to evaluate drugs inhibiting cellular influx associated with inflammatory response.