摘要：Feed containing β-carotene was administered orally to BALB/c mice immunized intraperitoneally with ovalbumin (OVA) for approximately 1 month. The titers of OVA-specific IgE, OVA-specific IgG1 and OVA-specific IgG2a in the mouse sera were determined. The OVA-specific IgE titer and OVA-specific IgG1 titer by mice fed β-carotene were significantly inhibited. On the other hand, the OVA-specific IgG2a titer in mice fed β-carotene was significantly greater than those of control mice. The OVA-specific IgE suppression of β-carotene feeding was dose-dependent. We also examined the effect of fed β-carotene on active systemic anaphylaxis. Feeding β-carotene to mice immunized with OVA inhibited the immediate reduction of the body temperature induced by antigen stimulation. Furthermore, the increase in serum histamine in the mice fed β-carotene under active systemic anaphylaxis was lower than in controls. We then examined the pattern of cytokine production by spleen cells from mice followed by restimulation with OVA in vitro . The spleen cells from the mice fed β-carotene produced more IFN-γ, IL-12 and IL-2 than those from the control group. In contrast, the spleen cells from the mice fed β-carotene produced less IL-4, IL-5, IL-6, IL-10 than those from the control group. Furthermore, analysis of IFN-γ mRNA levels of the splenocytes using the real-time quantitative RT-PCR technique revealed higher levels in the splenocytes from the mice fed β-carotene. These findings suggest that feeding β-carotene improves the helper T cell (TH)1–TH2 balance, inhibiting specific IgE and IgG1 production and antigen-induced anaphylactic response.
