Inhibitory effects of Houttuynia cordata water extracts on anaphylactic reaction and mast cell activation

The present study was investigated the effect of Houttuynia cordata THUNB water extract (HCWE) on mast cell-mediated anaphylactic reactions. The mast cell-mediated anaphylactic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. HCWE has been used as a traditional medicine in Korea and is known to have an antioxidant and anti-cancer activities. However, its specific effect of mast cell-mediated anaphylactic reactions is still unknown. We examined whether HCWE could inhibit compound 48/80-induced systemic anaphylaxis, IgE-mediated passive cutaneous anaphylaxis (PCA), and mast cell activation. The oral administration of HCWE inhibited compound 48/80-induced systemic anaphylaxis in mice. HCWE also inhibited the local allergic reaction, PCA, activated by anti-dinitrophenyl (DNP) IgE antibody in rats. HCWE reduced the compound 48/80-induced mast cell degranulation and colchicine-induced deformation of rat peritoneal mast cells (RPMC). Moreover, HCWE dose-dependently inhibited histamine release and calcium uptake of RPMC induced by compound 48/80 or anti-DNP IgE. HCWE increased the level of intracellular cAMP and inhibited significantly the compound 48/80-induced cAMP reduction in RPMC. These results suggest that HCWE may be beneficial in the treatment of mast cell-mediated anaphylactic responses.