The effect of feeding carrots on immunoglobulin E production and anaphylactic response in mice

Carrot juice was administered orally to BALB/c mice immunized intraperitone ally,vith dinitrophenylated (DNP)-OVA for about 1 month. The titers of DNP- specific IgE, DNP-specific IgG, and the levels of total IgE in mouse sera w ere determined. The DNP-specific IgE production by mice fed carrot juice wa s significantly inhibited. On the other hand, the DNP-specific IgG producti on and the level of total IgE in mice fed carrot juice were not significant ly different from those in control mice. We also examined the effect of feeding carrots on immediate-type hypersensi tivity. One hour after antigen stimulation, the ears of mice fed carrots sw elled less than those of control mice. Furthermore, the rise in serum hista mine in the mice fed carrots under active systemic anaphylaxis was lower th an in controls, We then examined the pattern of cytokine production by spleen cells from mi ce followed by restimulation with DNP-OVA in vitro. The spleen cells from t he mice fed carrots produced more interferon-gamma than those from the cont rol group. In contrast, the spleen cells from the mice fed carrots produced less interleukin-4 than those from the control group. Furthermore, the int erleukin-12 production of the spleen cells from mice fed carrots was also h igher than that of the control group, These findings suggest that feeding c arrots improves the helper T cell (Th)1/Th2 balance, inhibiting specific Ig E production and antigen-induced anaphylactic response.