Anti-inflammatory effect of Poncirus trifoliata fruit through inhibition of NF-kappaB activation in mast cells.

Mast cell-mediated allergic inflammation is involved in many diseases such as asthma, sinusitis, and rheumatoid arthritis. Mast cells induce synthesis and production of pro-inflammatory cytokines including tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 with immune regulatory properties. We investigated the effect of the fruits of Poncirus trifoliata (L.) Raf (Rutaceae) (FPT) on expression of pro-inflammatory cytokines by activated human mast cell line, HMC-1. FPT dose dependently decreased the gene expression and production of TNF-alpha and IL-6 on phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-stimulated HMC-1 cells. In addition, FPT attenuated PMA and A23187-induced activation of NF-kappaB indicated by inhibition of degradation of I kappa B alpha, nuclear translocation of NF-kappaB, NF-kappaB/DNA binding, and NF-kappaB-dependent gene reporter assay. Our in vitro studies provide evidence that FPT might contribute to the treatment of mast cell-derived allergic inflammatory diseases.