Pro- and anti-inflammatory activities of the latex from Calotropis procera (Ait.) R.Br. are triggered by compounds fractionated by dialysis

Previous studies have described pro- and anti-inflammatory activities displayed by the latex from Calotropis procera. This report aims to clarify these observations and shows that such activities can be segregated from the whole latex. The latex was divided into water-soluble fractions devoid of poly-isoprene by centrifugation and dialysis and both the activities were assayed by the peritonitis model in rats. The drugs dexamethasone, thalidomide, meclizine, indomethacin and celecoxib were used to modulate the inflammatory stimuli. Inflammation in rats was observed 2 h after intraperitoneal administration of the stimulus (DL fraction) in a dose dependent manner. This activity was inhibited by previous intravenous injection of dexamethasone, thalidomide and meclizine. Indomethacin and celecoxib did not reverse inflammation. These results suggest the involvement of histamine release and TNF-alpha mediated inflammation while prostaglandins seem not to be required. The anti-inflammatory fraction (NDL) inhibited inflammation triggered by proinflammatory fraction (DL) suggesting that NDL ought to follow a similar pathway of action to that of the anti-inflammatory drugs that were able to inhibit inflammation triggered by DL. Pro- and anti-inflammatory activities of the latex are displayed by compounds suitable to be fractionated on the basis of their molecular size.