Action of Ulmi radicis cortex extract on systemic and local anaphylaxis in rats.

1. To assess the contribution of an aqueous extract of Ulmi radicis cortex (AEURC) in systemic anaphylaxis, compound 48/80 was used as a fatal anaphylaxis inducer in rats. 2. AEURC completely inhibited anaphylactic shock with a dose of 1.0 g/kg body weight (BW) 1 hr before injection of compound 48/80. 3. AEURC significantly inhibited serum histamine levels induced by compound 48/80. 4. AEURC (1.0 g/kg BW) also inhibited by 79.1% passive cutaneous anaphylaxis activated by anti-dinitrophenyl (DNP) IgE. 5. AEURC dose dependently inhibited the histamine release from the rat peritoneal mast cells (RPMCs) by compound 48/80. Moreover, AEURC had a significant inhibitory effect on anti-DNP IgE-induced histamine release and tumor necrosis factor-alpha production from RPMC. 6. The level of cAMP in RPMC, when AEURC was added, significantly increased compared with that of a normal control. 7. These results indicate that AEURC may possess strong antianaphylactic action.