Anti-allergic and anti-anaphylactic activity of picroliv - A standardised iridoid glycoside fraction of Picrorhiza kurroa

Picroliv, a standardised iridoid glycoside fraction from the root and rhizo me of Picrorhiza kurroa at a dose of 25 mg kg(-1) p.o. inhibited passive cu taneous anaphylaxis in mice (82%) and rats (50-85%) and protected mast cell s from degranulation (60-80%) in a concentration-dependant manner. Its effe ct was also studied in sensitised guinea pig ileum preparation in vitro (Sc hultz-Dale study) and in normal guinea pigs in vivo (Konzett-Rossler, in pr eparation). There was inhibition of the Schultz-Dale response in sensitised guinea pig ileum, but the bronchospasm induced by histamine could not be a ntagonised or prevented by Picroliv, indicating the absence of a direct pos t-synaptic histamine receptor blocking activity. (C) 1998 The Italian Pharm acological Society.