The current study characterizes the mechanism by which the seed extract of Moringa oleifera Lam (Moringaceae) decreases the mast cell-mediated immediate type hypersensitivity reaction. The immediate type hypersensitivity reaction is involved in many allergic diseases such as asthma and allergic rhinitis. Moringa oleifera, a shrub widely used in the traditional medicine in India, has been reported to possess anti-cancer, hypotensive, anti-arthritic, and anti-inflammatory activities. In the present study, the effects of the ethanolic extract of seeds of Moringa oleifera (MOEE-herbal remedy) on systemic and local anaphylaxis were investigated. The potential anti-anaphylactic effect of MOEE was studied in a mouse model of Compound 48/80-induced systemic anaphylactic shock. Passive cutaneous anaphylaxis activated by anti IgE-antibody was also used to assess the effect of MOEE. In addition, rat peritoneal mast cells (RPMC) were used to investigate the effect of MOEE on histamine release induced by compound 48/80. When administered 1 hr before 48/80 injection, MOEE at doses of 0.001-1.000 g/kg completely inhibited the inducible induced anaphylactic shock. MOEE significantly inhibited passive cutaneous anaphylaxis activated by anti-IgE antibody at a dose of 1 g/kg. When MOEE extract was given as pretreatment at concentrations ranging 0.1-100 mg/ml, the histamine release from the mast cells that was induced by the 48/80 was reduced in a dose-dependent manner. These results suggest a potential role for MOEE as a source of anti-anaphylactic agents for use in allergic disorders.