The suppressive effect of tamarixetin, isolated from Inula japonica, on degranulation and eicosanoid production in bone marrow-derived mast cells.

Abstract

The study aimed to evaluate the inhibitory effect of tamarixetin on the production of inflammatory mediators in immunoglobulin E /antigen-induced mouse bone marrow-derived mast cells (BMMCs). Tamarixetin isolated from Inula japonica was infected into BMMCs. The inhibitory effect of tamarixetin were analyzed by quantifying β-hexosaminidase, eicosanoid generation, intracellular calcium measurement, and Western blot analysis. Tamarixetin effectively decreased degranulation and the eicosanoid generation such as leukotriene C4 and prostaglandin D2 in BMMCs. To elucidate the mechanism involved, we investigated the effect of tamarixetin on the phosphorylation of signal molecules. Tamarixetin inhibited the phosphorylation of protein kinase B (Akt) and its downstream signal molecules including IκB kinase and nuclear factor-κB. Besides, tamarixetin downregulated the phosphorylation of cytosolic phospholipase A2 and p38 mitogen-activated protein kinase.Conclusion: In summary, tamarixetin inhibits degranulation and eicosanoid generation through the phospholipase Cγ1 as well as Akt pathways. It could be potential for the prevention of allergic inflammatory diseases in BMMCs.