Conclusions
This study suggests that IFE modulates eicosanoids generation and degranulation through the suppression of SCF-mediated signaling pathways that would be beneficial for the prevention of allergic inflammatory diseases. Anti-allergic activity of IFE may be in part attributed particularly to the presence of britanin and tomentosin as major components evidenced by a HPLC analysis.
Methods
The anti-allergic activity of IFE was evaluated using mouse bone marrow-derived mast cells (BMMCs) in vitro and a passive cutaneous anaphylaxis (PCA) animal model in vivo. The effects of IFE on mast cell activation were evaluated in terms of degranulation, eicosanoid generation, Ca(2+) influx, and immunoblotting of various signaling molecules.
Results
IFE inhibited degranulation and the generation of eicosanoids (PGD(2) and LTC(4)) in stem cell factor (SCF)-stimulated BMMCs. Biochemical analysis of the SCF-mediated signaling pathways demonstrated that IFE inhibited the activation of multiple downstream signaling processes including mobilization of intracellular Ca(2+) and phosphorylation of the mitogen-activated protein kinases (MAPKs), PLCγ1, and cPLA(2) pathways. When administered orally, IFE attenuated the mast cell-mediated PCA reaction in IgE-sensitized mice. Its major phytochemical composition included three sesquiterpenes, 1-O-acetylbritannilactone, britanin and tomentosin. Conclusions: This study suggests that IFE modulates eicosanoids generation and degranulation through the suppression of SCF-mediated signaling pathways that would be beneficial for the prevention of allergic inflammatory diseases. Anti-allergic activity of IFE may be in part attributed particularly to the presence of britanin and tomentosin as major components evidenced by a HPLC analysis.