Abstract: The aim of this study was to determine the immunoregulatory effect of lactoferrin on Th1/Th2 cell balance in the peripheral blood of mice with food allergy. In order to establish allergic mouse models, BALB/C mice were repeatedly sensitized and challenged with ovalbumin. Lactoferrin was administrated to mice during preventive treatment or intragastric provocation. The levels of serum IgE, IFN-γ, IL-4, IL-6, IL-10, IL-12p40 and TGF-β were determined at 1 h after the last administration. The results showed that Th1/Th2 cell balance in the peripheral blood of mice with food allergy revealed a shift towards Th2 cell direction. Lactoferrin administration at 2 mg/(kg•d) significantly increased IFN-γ and IL-12p40 levels and IFN-γ/IL-4 ratio, but decreased IgE, IL-4 and IL-6 levels during intragastric provocation. When the dosage was increased to 20 mg/(kg•d), these cytokines except IFN-γ/IL-4 ratio were significantly decreased. Meanwhile, lactoferrin administration significantly increased the levels of serum IL-4, IL-6, IL-10, IL-12p40, IFN-γ, TGF-β and IgE during preventive treatment, especially at 20 g/(kg•d), resulting in a significant increase in IFN-γ/IL-4 ratio. Therefore, lactoferrin can promote Th1/Th2 cell balance in ovalbumin-induced food allergy mice.

Key words: food allergy, lactoferrin, Th1/Th2 cell balance, immunoregulatory effect