Resveratrol is a natural phytoalexin occurring in grapes, vines and peanuts and possesses both antitumor and antioxidation capabilities. Its chemoprotective actions are attributed partially to its anti-inflammation effect. The present study is aimed at checking the inhibitory actions of resveratrol on the release of mediators from bone marrow-derived mouse mast cells (BMMC) in vitro. Mast cells were prepared by isolating bone marrow cells from intact mice femora and culturing them for 4 weeks in the presence of IL-3 and FCS. The release reaction was triggered by IgE or calcium ionophore (A23187). Mediated by IgE, the release of histamine and tumor necrosis factor-alpha was significantly inhibited by resveratrol at a concentration of 100 microM; IgE-mediated release of leukotrienes and prostaglandin D (2) was also strongly suppressed at concentrations of 100 and 10 microM. Also, A23187-mediated release of histamine and leukotrienes release was strongly reduced by resveratrol at concentrations of 100 and 10 microM, respectively. Resveratrol exhibited its behavior without a significant cytotoxic activity against mast cells. In conclusion, resveratrol is a potent non-selective inhibitor of mediator release from activated mast cells and deserves further investigation of its biological modulations.