Plants containing allergens What are allergens? An allergen is any exogenous substance usually an antigen, which produces an abnormally vigorous immune response by triggering the production of specific Immunoglobin E IgE antibodies produced by activated B-lymphocytes cells. This activated immune response fights off a perceived threat that would otherwise be harmless to the body. Such immune reactions in response to the allergen are called as allergies. Mode of action Allergens are protein in nature and their activity depends upon their ability to interact with specific IgE antibodies. These IgE antibodies bind to the surface of the mast cells via IgE receptors, this occurs when first time an allergy prone person comes across an allergen. Upon re-exposure the allergen binds the already bounded IgE and activates the mast cells releasing a variety of vasoactive mediators causing a hypersensitivity reaction and the symptoms of allergy. Mast cells are the r...