Ursodeoxycholic acid inhibits histamine release from rat peritoneal mast cells

Although the immunomodulatory properties of ursodeoxycholic acid (UDCA) have been well documented, the effects of UDCA on mast cell function are unknown. The aim of the present study was to investigate in vitro the effects of UDCA on histamine release from mast cells induced by a hydrophobic bile acid (i.e. chenodeoxycholic acid) and by classical mast cell activators (i.e. compound 48/80 and concanavalin A). We incubated 5 x 10(5) purified rat peritoneal mast cells with the aforementioned agents in the presence or absence of UDCA and assessed the extent of mast cell activation by quantitating the release of histamine, a prototypic mast cell-derived mediator, UDCA dose-dependently inhibited histamine release from mast cells induced by chenodeoxycholic acid, compound 48/80, and concanavalin A. Our in vitro data suggest a hitherto unrecognized, inhibitory action of UDCA on histamine release from mast cells and a potential benefit of UDCA for mast cell-related disorders.