Dehydroandrographolide inhibits IgE-mediated anaphylactic reactions via calcium signaling pathway.

The classical mast cells degranulation pathway is mediated by FcεRI aggregation and varies in strength among subjects. Dehydroandrographolide (DA) is one of principal components of Andrographis paniculata (Burm.f.) Nees (family: Acanthaceae) and considered the main contributors of its therapeutic properties, such as anti-tumor. In this study, inhibition of IgE-mediated anaphylactic reactions and anti-inflammatory potential of DA were investigated. The anti-anaphylactic activity of DA was investigated using skin swelling and extravasation assays in vivo and mast cell degranulation assay in vitro. The release of cytokines was measured using ELISA kits. Human Phospho-Kinase Array kit and western blotting were used to explore the related molecular signaling pathways. DA inhibited IgE-mediated mast cell activation, including degranulation and release of cytokines in vitro. Moreover, DA reduced the degree of swelling and Evans blue exudation of mice paw in a dose-dependent manner by inhibiting mast cell degranulation. DA obviously reduced the concentrations of histamine, TNF-α, MCP-1, IL-8, IL-13, and IL-4 in mice serum and inhibited IgE-mediated anaphylactic reactions as a potential P-PLCγ inhibitor. Our study reveals that DA can inhibit allergic responses in vivo and in vitro, and it may be regarded as a novel P-PLCγ inhibitor for preventing mast cell-immediate and delayed allergic diseases.