Suppression of immunoglobulin E-mediated anaphylactic reaction by Alpinia oxyphylla in rats.

We investigated the effect of Alpinia oxyphylla water extract (AOWE) on immunoglobulin E (IgE)-mediated anaphylaxis activated by anti-dinitrophenyl (DNP) IgE antibody. AOWE dose-dependently suppressed passive cutaneous anaphylaxis (PCA) when intraperitoneally or orally administered. On the other hand, it showed weak suppressive activity when administered intravenously. AOWE dose-dependently suppressed anaphylactic histamine release from rat peritoneal mast cells (RPMC) activated by anti-DNP IgE antibody. However, AOWE had a significant augmenting effect on anti-DNP IgE antibody-induced tumor necrosis factor-alpha secretion from RPMC. These results indicated that AOWE may possess strong antianaphylactic action and also suggest that differential activity following administration routes may be caused by difference of bioavailability.