Effect of Terminalia chebula on Immediate Hypersensitivity Reaction in Mice and Rats

We investigated the effect of aqueous extract of Terminalia chebula (Combretaceae)(TCAE) on the immediate hypersensitivity reaction in vivo and in vivo. TCAE (0.01 to 1 g/kg) dose-dependently inhibited compound 48/80 induced systemic anaphylaxis in mice. When TCAE was pretreated at concentrations ranging from 0.01 to 1 g/kg, the plasma histamine levels were reduced in a dose-dependent manner. TCAE (0.1 and 1 g/kg) significantly inhibited local immunoglobulin E (IgE)-mediated passive cutaneous anaphylactic reaction. TCAE (0.001 to 1 mg/ml) also dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-dinitrophenyl (DNP) IgE. TCAE (0.01 to 1 mg/ml) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis $factor-{\alpha}$ production from RPMC. These results indicate that TCAE inhibits immediate hypersensitivity reaction in vivo and in vitro.