Bioactivity-boosting strategy based on combination of anti-allergic O-methylated catechin with a Citrus flavanone, hesperetin

Many patients with allergies have anxiety about taking anti-allergic medicines due to their side effects and increased medical expenses. Thus, developing functional foods/agricultural products for allergy prevention is strongly desired. In this study, we revealed that a Citrus flavanone, hesperetin, amplified IgE/antigen-mediated degranulation-inhibitory potency of anti-allergic catechin, (–)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3ʹʹMe), in the rat basophilic/mast cell line RBL-2H3. Hesperetin also significantly elevated the activation of acid sphingomyelinase (ASM), essential for eliciting anti-allergic effect of EGCG3ʹʹMe through the cell surficial protein, 67-kDa laminin receptor (67LR). Furthermore, oral administration of the highly absorbent hesperidin, α-glucosyl hesperidin, also enhanced the inhibitory potency of EGCG3ʹʹMe-rich ‘Benifuuki’ green tea (Camellia sinensis L.) on passive cutaneous anaphylaxis (PCA) reaction evoked by IgE/antigen in BALB/c mice. These observations indicate that hesperetin amplifies the ability of EGCG3ʹʹMe to inhibit the IgE/antigen-mediated degranulation through activating ASM signaling. Graphical abstract: [Figure not available: see fulltext.].