Background Soybean protein is used in a number of food products but is also a common cause of food allergy. Soybean glycinin and β-conglycinin represent up to one-third of protein in the soybean. Many reports have indicated that glycinin and β-conglycinin have been characterized as major soybean allergens involved in food hypersensitivity.
Objective To investigate oral allergy syndrome and anaphylactic reactions in BALB/c mice caused by soybean glycinin and β-conglycinin with an intragastric feeding protocol without using an adjuvant.
Methods BALB/c mice were sensitized by gavages with glycinin and β-conglycinin, and allergen-specific IgE and IgG1 responses were studied by a passive cutaneous anaphylaxis assay. Serum histamine release and blood pressure were measured according to other methods. Epithelium and mast cell dye used the method of light microscopy.
Results Sensitization with soybean allergens induced high levels of antigen-specific IgE and IgG1 and increased serum histamine in BALB/c mice. Percentiles of intact mast cell of small intestine in mice sensitized with glycinin and β-conglyinin significantly decreased for 28 days. Degranulation of mast cells and damage of the epithelium in the small intestine of mice sensitized with globulins were observed. The level of blood pressure in sensitized mice reached a minimum at 3 h.
Conclusion Soybean-specific IgE and IgG1 antibodies increased, with high levels of histamine release, severe degranulation of mast cells and damage of the epithelium of small intestine in mice sensitized with glycinin and β-conglyinin.