Inhibition of rat intestinal anaphylaxis by various anti-inflammatory agents.

Adverse reactions to food may, in some cases, be due to IgE-mediated immune reactions to the ingested antigens. A mast cell protector has been shown to protect patients against challenge with food to which they are sensitive. An IgE-mediated intestinal anaphylaxis reaction in the rat has been developed as a model of some aspects of human food allergy. Using this model, a number of xanthones and other anti-inflammatory agents were tested for activity in inhibiting intestinal anaphylaxis. The compounds were also tested for inhibitory activity against the IgE-mediated rat passive cutaneous anaphylaxis reactions. The xanthones protected against both reactions, as did isoproterenol and cyproheptadine, while aspirin, indomethacin, and dexamethasone inhibited the intestinal but not the cutaneous reaction. This suggests that while IgE-triggered mediator release from mast cells is important in both reactions, other mechanisms may also be operative in the intestinal reaction. Furthermore, the use of xanthones and other anti-inflammatory compounds may be a useful mode of therapy in human food allergy.