3,5,6,7,8,3',4'-Heptamethoxyflavone reduces interleukin-4 production in the spleen cells of mice.

In our previous studies, we reported anti-inflammatory functions of 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF), which is a polymethoxyflavone rich in various citrus fruits. Here, we investigated the immunomodulatory function of HMF in mice. HMF administration (50 mg/kg, i.p., 2 times/week) tended to reduce the production of antigen-specific IgE induced by ovalbumin in combination with aluminum hydroxide gel. Fluorescence-activated cell sorting analysis revealed the reduction of interleukin-4(+)CD4(+) spleen cells and sustained presence of interferon-γ(+)CD4(+) spleen cells in mice administered HMF, whereas the ratio of CD4(+)CD8(-) versus CD4(-)CD8(+) spleen cells was not affected. Interleukin-4 release from CD3/CD28-stimulated spleen cells of mice administered HMF was reduced, whereas interferon-γ release was not affected. These results suggest that HMF has an immunomodulatory function via reduced interleukin-4 expression.