Abstract: N-(3', 4', 5'-Trimethoxycinnamoyl) ortho-aminobenzoic acid (TOA), at the concentration of 80 μg/ml, significantly inhibited the antigen-induced contraction of ileum isolated from the actively sensitized guinea-pig. At the concentrations of 25 and 50 μg/ml, TOA inhibited homocytotropic antibody-mediated degranulation of mast cells in the rat mesentery, and also inhibited anaphylactic histamine release from rat peritoneal mast cells.

Key words: Cinnamoyl amines, Ileum, Mast cells, Degranulation, Histamine