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

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 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 C and prostaglandin D 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 A and p38 mitogen-activated protein kinase. : 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.