Eppikajutsuto Protects against Food Allergy Induced by Ovalbumin in a Murine Model

Abstract

Background: Currently, there are no efficient medications available for the prevention and treatment of food allergy (FA). Herbal medicines, including traditional Japanese Kampo medicines (TJKMs), are promising therapeutic drugs. Methods: We screened 18 TJKMs for treatment of FA symptoms in a mouse FA model induced by ovalbumin (OVA). BALB/c mice were sensitized intraperitoneally by an OVA/aluminum hydroxide gel mixture followed by 4 booster doses of oral OVA and FA symptom induction by 50 mg of OVA. TJKMs were orally administered for 28 days from the day of sensitization to the day before FA symptom induction. Evaluated FA symptoms included a decrease in body temperature and allergic diarrhea. Allergic sensitization was determined by plasma OVA-specific IgE levels. Cytokine mRNA levels in mesenteric lymph nodes, plasma mouse mast cell protease-1, and the number of mast cells in the small and large intestines were analyzed. Additionally, the therapeutic effect of the TJKM eppikajutsuto (EJT) on mast cell degranulation was determined in active anaphylaxis and passive cutaneous anaphylaxis models. Results: EJT effectively prevented FA symptoms. Although OVA-specific IgE levels and the intestinal mast cell numbers were not different between the EJT-treated and untreated FA mice, plasma mMcpt1 and IL-4 levels were lower in EJT-treated FA mice than untreated FA mice. EJT could alleviate symptoms in both active and passive anaphylaxis models. Conclusion: EJT prevented OVA-induced FA symptoms in a mouse model, suggesting that EJT might exert its therapeutic activity via IL-4 suppression and the inhibition of mucosal mast cell degranulation.