Denatonium benzoate promotes IgE-mediated mast cell degranulation and ovalbumin-induced allergic diarrhea in BALB/c mice.

BACKGROUND

Denatonium benzoate (DB), one of the most bitter compounds known to man, is used for alcohol denaturation. Some reports have demonstrated that asthmatic symptoms are associated with DB exposure, but the possible links between DB and immunoglobulin E (IgE)-mediated allergy susceptibility have not yet been examined.

OBJECTIVE

This study investigated the effects of DB on in vitro IgE-mediated mast cell degranulation and food allergy in BALB/c mice.

METHODS

IgE-sensitized rat RBL-2H3 cells (a basophilic leukemia mast cell line) and human KU812 cells (a basophilic cell line) and mice with ovalbumin (OVA)-induced allergy were treated with DB. Histamine release, calcium ion (Ca²⁺) influx, phosphorylated spleen tyrosine kinase (p-Lyn) and phosphorylated phospholipase C-γ (p-PLCγ) levels, OVA-specific IgE, anaphylactic symptoms, and the cell-surface expression of the high-affinity IgE receptor α-subunit (FcεRIα) on mast cells were evaluated.

RESULTS

DB increased histamine release, Ca²⁺ mobilization, and p-Lyn and p-PLCγ levels in IgE-mediated activated RBL-2H3 and KU812 cells, and enhanced the cell-surface expression of FcεRIα messenger RNA (mRNA). In mice, DB increased the severity of OVA-induced anaphylactic and diarrheic symptoms, the mucus thickness in the jejunum, histamine and OVA-specific IgE levels, and FcεRIα mRNA in isolated mucosal mast cells.

CONCLUSIONS

Our work indicates that DB promotes IgE-mediated mast cell degranulation and OVA-induced allergic diarrhea in BALB/c mice, providing evidence that exposure to DB promotes allergy susceptibility.