Characterization of cAMP as an anti-allergic functional factor in Chinese jujube (Ziziphus jujuba Mill.)

Chinese jujube has been valued for its medical properties. To examine the beneficial role of jujube in regulating the immune response, we investigated the anti-allergic effects of jujube extract and cyclic adenosine monophosphate (cAMP), a functional compound of jujube extract, using a mouse allergy model and rat basophilic leukemia (RBL)-2H3 mast cells. The investigations of the immunomodulatory effects of jujube extract on RBL-2H3 mast cell degranulation showed that the release of beta-hexosaminidase (beta-hex) was inhibited. In mice with ovalbumin (OVA)-induced allergic rhinitis, cAMP reduced the secretion of IgE and histamine in the plasma. cAMP regulated both Th1 and Th2 cytokines levels in the plasma. In addition, cAMP inhibited beta-hex release and blocked extracellular Ca2+ influxes in RBL-2H3 cells. Our results demonstrate that jujube, as well as cAMP, suppressed cytokine production in the allergic response pathway, which resulted in prevention or alleviation of allergy symptoms.