Nobiletin is a polymethoxy flavonoid present in fruit tissues of citrus species and has been reported to suppress degranulation of RBL-2H3 cells.Nobiletin suppressed degranulation of both RBL-2H3 cells and bone marrow-derived mast cells induced by antigen stimulation. Nobiletin also suppressed degranulation stimulated by the calcium ionophore A23187 and thapsigargin, a specific inhibitor of the Ca²⁺-dependent ATPase.Some experiment show that nobiletin suppresses Ca²⁺ influx and consequently exerts the anti-allergy activity in a similar way to wortmannin.

Nobiletin reduced degranulation of RBL-2H3 cells and bone marrow-derived mast cells induced by antigen.
Nobiletin suppressed degranulation of RBL-2H3 cells induced by A23187 and thapsigargin.
Phosphorylation of PI3K and PLCγ1 was down-regulated by nobiletin.
Oral administration of nobiletin attenuated vascular permeability in PCA model mice.
Nobiletin suppressed allergic responses in a similar way to wortmannin.