Inhibitory effects of dehydrocorydaline isolated from Corydalis Tuber against type I-IV allergic models.

An alkaloidal component, dehydrocorydaline (DHC) isolated from Corydalis Tuber (tuber of Corydalis turtschaninovii forma yanhusuo), has been screened for activity against types I-IV allergic reactions. In a type I allergic models, DHC at a dose of 0.5 mmol/kg, p.o. inhibited 48 h homologous passive cutaneous anaphylaxis (PCA) in rats, which is related to IgE. DHC also exhibited an inhibitory effect on antigen-induced histamine release from peritoneal mast cells. In a type II allergic model, DHC did not inhibit reversed cutaneous anaphylaxis (RCA) in rats. In a type III allergic model, DHC showed weak inhibition on direct passive arthus reaction (DPAR) in rats. Furthermore, in a type IV allergic model, DHC had inhibitory effects on the induction phase and effector phase in picryl chloride-induced contact dermatitis (PC-CD). These results indicated that DHC not only inhibits antibody-mediated allergic reactions but also influences cell-mediated allergia reactions, and the inhibitory effect of Corydalis Tuber on allergic reactions may be partially attributed to DHC.