Percutaneous Sensitization to Soybean Proteins Is Attenuated by Oral Tolerance

Oral tolerance prevents allergic responses, but cutaneous exposure to food allergens predisposes individuals to food allergies. Soybean, a major allergenic food, is also an ingredient in various cosmetic products. However, it remains to be determined whether oral tolerance prevents percutaneous sensitization to soybean proteins in humans or animal models. In this study, BALB/c mice were divided into three groups; the SS group fed a soybean-containing diet, and the CS and control (C) groups fed a soybean-free diet. After being dorsally shaved, the CS and SS groups were epicutaneously exposed to a soybean extract while the control group was exposed to only the carrier. Specific IgE and IgG1 immunoglobulins secreted in response to the soybean proteins were measured using enzyme-linked immunosorbent assays. Exposure to the soybean extract elicited the secretion of IgE and IgG1 specific for Gly m 5 and Gly m 6, and trypsin inhibitor. Oral soybean consumption attenuated the secretion of all the soybean-specific IgEs and IgG1s, suggesting that percutaneous sensitization to soybean proteins is attenuated by oral tolerance.