Beneficial effects of chelidonic acid on a model of allergic rhinitis.

Chelidonic acid (CA) is known as an inhibitor of the rat brain glutamate decarboxylase. However, the pharmacological effects of CA in allergic reactions have not yet been defined. Here, we show the effects and the mechanism of CA in the ovalbumin (OVA)-sensitized allergic rhinitis (AR) model. CA significantly decreased the number of nasal/ear rubs and increment of IgE levels in the AR mice. The level of interferon-γ was enhanced while the level of IL-4 was reduced on the spleen tissue of the CA-administered AR mice. Expressions of IL-1β and cyclooxygenase-2 were inhibited by CA administration in the nasal mucosa tissues. Infiltration of eosinophils and mast cells was decreased in the CA-administered AR mice. Furthermore, CA decreased the caspase-1 activity in the same nasal mucosa tissue and human mast cell line, HMC-1. Our results indicate that CA may attenuate allergic reaction by inhibition of caspase-1 activity.