Anaphylactic reactions in mice with Fenugreek allergy.

Fenugreek is a legume mostly used as a spice in Indian-style cooking. Although it has been used since ancient times, its allergenicity has only been reported in the last two decades. It poses special problems as an emerging and often hidden allergen. Fenugreek exposure may have serious implications also for individuals with peanut allergy because of cross-reactivity. Because a new food requires a model specially designed for that particular food, the aim of our study was to develop a food allergy model of fenugreek in mice with anaphylaxis as the endpoint. Mice were immunized perorally using cholera toxin as adjuvant. A two-compartment response surface design with immunoglobulin (Ig)E as the main variable was used to estimate the optimal sensitizing dose of fenugreek, which was further used to evaluate the model. The mice were challenged perorally with a high dose of fenugreek, and signs of anaphylactic reactions were observed. Challenged mice showed high levels of mouse mast cell protease-1, developed specific IgE against several proteins in the fenugreek extract, had elevated levels of IgG1 and IgG2a and showed a general shift towards a Th2 response as determined by ex vivo production of cytokines. Total IgE levels were substantially decreased after challenge. In conclusion, we have established a mouse model of IgE-mediated fenugreek allergy demonstrating anaphylactic reactions upon challenge. There is little information on fenugreek cross-allergy to other legumes like peanut, soy and lupin, and we expect that this model will be a valuable tool in further research on legume allergy.