Resveratrol is a phytoalexin abundantly found in red grape skin and is effective in antitumor and antiinflammation associated with immune responses. This study investigated whether resveratrol suppressed immunoglobulin (Ig)Emediated allergic responses and passive cutaneous anaphylaxis (PCA) in rat RBL-2H3 mast cells and in BALB/c mice. The release of β-hexosaminidase and histamine was enhanced in mast cells sensitized with anti-dinitrophenyl (DNP)-IgE and subsequently stimulated by DNP-human serum albumin (HSA), indicative of mast cell degranulation. When mast cells were pretreated with nontoxic resveratrol at 1-25 μmol/L, such induction was dose dependently diminished. Spleen tyrosine kinase (Syk) and phospholipase Cγ (PLCγ) of sensitized mast cells were activated by stimulation with DNP-HSA antigen, which was dampened by ≥5 μmol/L resveratrol. The phosphorylation of protein kinase C (PKC)μ and PKCθ was attenuated by administering resveratrol to DNP-HSA-exposed mast cells, whereas quiescent PKCζ/λ in sensitized cells was dose-dependently activated by resveratrol. Male BALB/c mice were sensitized for 24 h with DNP-IgE and orally administered with resveratrol 1 h before the DNP-HSA challenge. The histamine concentration was enhanced in sensitized mice challenged to DNP-HSA, which was reversed by administration of 10 mg/kg resveratrol. Additionally, it encumbered the tissue activation of Syk, PLCγ, and PKCμ in antigen-exposed mice. Resveratrol decreased IgE-mediated PCA and alleviated allergic edema of mouse ear and dorsal skin. Mast cell degranulation and allergic inflammation, accompanying the induction of monocyte chemotactic protein-1 and macrophage inflammatory protein-2, were inhibited by supplementing resveratrol to antigen-challenged mice. Resveratrol inhibited mast cell-derived, immediate-type allergic reactions, and these responses of resveratrol suggest possible therapeutic strategies in preventing allergic inflammatory diseases.
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