22A-3 exerts anti-allergic activity through TGF-β secretion in passive cutaneous anaphylaxis of mice.

Allergy is a global issue, however, medical intervention for allergy treatment is limited. Recent studies have focussed on allergy prevention with food factors. In this study, 22 A-3 (LP22A3) exerted an anti-allergic effect in passive cutaneous anaphylaxis (PCA) reaction and increased transforming growth factor (TGF)-β contents in blood. The increase of TGF-β contents in blood by exogenous TGF-β injection intraperitoneally decreased Evans blue release into mice ears to the same level as LP22A3 treatment in PCA reaction. LP22A3 treatment directly to RBL-2H3 cells shows no effect on β-hexosaminidase release from RBL-2H3 but inhibited its release using the Caco-2/RBL-2H3 cells co-culture system stimulated with LP22A3 from the apical side. Moreover, TGF-β treatment to RBL-2H3 inhibited β-hexosaminidase release from RBL-2H3. However, β-hexosaminidase release was cancelled by TGF-β neutralising antibody without the influence of TGF-β mRNA expression in Caco-2 cells. These results showed that LP22A3 ameliorates allergy by TGF-β secretion through the intestine.