Amomum xanthiodes inhibits mast cell-mediated allergic reactions through the inhibition of histamine release and inflammatory cytokine production

In this study, we investigated the effect of Amomum xanthiodes (Zingiberaceae) extract (AXE) on the mast cell-mediated allergy model and studied the possible mechanism of action. We found that AXE inhibited compound 48/80-induced systemic reactions and plasma histamine release in mice. Additionally, AXE decreased immunoglobulin E (IgE)-mediated local allergic reactions and passive cutaneous anaphylaxis (PCA), and AXE dose-dependently attenuated the release of histamine from rat peritoneal mast cells (RPMC) activated by compound 48/80 or IgE. The amounts of AXE needed for inhibition of compound 48/80-induced plasma histamine release and PCA were similar to disodium cromoglycate, the known anti-allergic drug. We found that AXE increased the cAMP levels and decreased the compound 48/80-induced intracellular Ca ²⁺. Furthermore, AXE attenuated the phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore (A23187)-stimulated tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 secretion in human mast cells. The inhibitory effect of AXE on the proinflammatory cytokines was nuclear factor-κB (NF-κB)-dependent. In addition, AXE decreased PMA plus A23187-induced degradation of IκBα and the nuclear translocation of NF-κB. Our findings provide evidence that AXE inhibits mast cell-derived immediate-type allergic reactions, and that cAMP, intracellular Ca²⁺, proinflammatory cytokines, and NF-κB are involved in these effects.