Objective: Enzymatic hydrolysis has been identified to be a very effective way to reduce the sensitization of β-lg compared to other treatments. The aim of this study was to explore whether enzymatic hydrolysis could reduce the allergenicity of native bovine β-lg.

Methods: β-lg was hydrolyzed by trypsin. Twenty four BALB/c mice were divided into three groups and orally sensitized by native bovine β-lg and its hydrolysates five times at weekly intervals.

Results: During the sensitization period, many serious systemic anaphylactic symptoms were observed in mice sensitized by native β-lg compared to hydrolysates of β-lg. Mice sensitized by hydrolysates of β-lg showed a significantly lower spleen lymphocyte proliferation level than intact β-lg. The β-lg-specific IgE antibody levels in serum and intestinal fluid samples induced by native β-lg were significantly elevated. Plasma histamine levels were also evaluated and showed the same trend as IgE. Moreover, the hydrolysates of β-lg significantly up-regulated IFN-γ and IL-10 production and down-regulated IL-4 and IL-5 secretions by murine splenocytes.