Inhibitory Effects of Eriodictyol-7-O-beta-D-glucuronide and 5,7-Dihydroxy-4-chromene Isolated from Chrysanthemum zawadskii var. latilobum in Fc epsilon RI-Mediated Human Basophilic KU812F Cell Activation

Chrysanthemum zawadskii var. latilobum (CZL) has been used in Eastern medicine for the treatment of various diseases, such as pneumonia, bronchitis, cough, the common cold, pharyngitis, bladder-related disorders, gastroenteric disorders, and hypertension. In the present study, we isolated two strong antiallergic compounds from CZL, namely, eriodictyol-7-O-beta-D-glucuronide (EDG) and 5,7-dihydroxy-4-chromene (DC), and investigated their antiallergic effects in Fc epsilon RI-mediated human basophilic KU812F cells. EDG and DC downregulated the protein and messenger RNA (mRNA) expression of Fc epsilon RI on the cell surface. Moreover, Western blotting analysis showed that EDG and DC inhibited the expression of protein tyrosine kinases such as Syk and Lyn, and extracellular-regulated kinases (ERK) 1/2. These results suggested that EDG and DC, antiallergic constituents of CZL, are potential therapeutic candidates for protection against and for the treatment of allergic disorders.