Reduction of allergic symptoms in NC/Jic Jcl mice fed a diet containing casein phosphopeptide preparation, CPP‐III

The effect of a commercially available dietary casein phosphopeptide preparation, CPP‐III, consisting mainly of bovine αs2‐casein (1–32) and β‐casein (1–28) on the development of allergic symptoms mediated by IgE antibody was investigated in NC/Jic Jcl mice. No significant difference was observed in the change in mean bodyweight between mice given a diet of a mixture of ovalbumin and CPP‐III (CPP‐III‐added diet) and those given a diet of ovalbumin alone (control diet) as a protein source. Total allergic score of five mice given the CPP‐III‐added diet was less than half that of those given the control diet for 13 weeks. Levels of intestinal total and ovalbumin‐specific immunoglobulin (Ig)A were significantly higher in the CPP‐III‐added diet group than in the control diet group, while the serum ovalbumin‐specific IgE level was significantly smaller in the former. The production of interleukin (IL)‐6 by spleen cells from mice that ingested the CPP‐III‐added diet for 13 weeks was obviously higher than that by spleen cells from mice administered the control diet, while the formation of IL‐4 by spleen cells from the former mice was significantly lower than that by the latter mouse. These results suggest that the oral ingestion of CPP‐III may be beneficial in reducing allergic symptoms mediated by IgE antibody.