In Vitro Antiallergic Activity of Flavonoids in Histamine Release Assay Using Rat Basophilic Leukemia (RBL-2H3) Cells

Abstract

We used an established cell line, rat basophilic leukemia cells (RBL-2H3) to screen 40 flavonoids for inhibitory activity on antigen-induced histamine release from immunogloblin E (IgE)-sensitized RBL-2H3 cells. To exclude non-specific inhibition, the cytotoxicity to RBL-2H3 cells was simultaneously determined. Flavonoid aglycones showed a stronger activity for histamine release-inhibition and cytotoxicity than glycosides, and both activities were almost in parallel. Baicalein showed histamine release-inhibitory activity with the IC5o of 1.07 X 10∼5M in this bioassay system. However, it showed a potent cytotoxicity (IC5o 9.62 X 10∼6M). On the other hand, scutellarein (4′-hydroxybaicalein) showed a potent histamine release-inhibitory activity (IC50 3.15 x 10∼6M) and low cytotoxicity (IC5o 6.11 X 10∼5M). We found that scutellarein has a potent histamine release-inhibitory activity and low cytotoxicity. © 1994, Japanese Society for Food Hygiene and Safety. All rights reserved.