Abstract
Soybean isoflavones are expected to reduce the risks of various diseases. In this study, anti-allergic effects of soybean isoflavones such as genistein and daidzein, and equol, a metabolite of daidzein, were investigated by measuring the chemical mediators, leukotriene B4 (LTB4) and histamine, released from rat peritoneal exudate cells (PEC) in vitro. Genistein and equol significantly suppressed the release of LTB4 from PEC stimulated by calcium ionophore without cytotoxicity, whereas the inhibitory effect of daidzein was weak. In contrast, they had no effect on the release of histamine from calcium ionophore-stimulated PEC. These data suggest that the soybean isoflavones and metabolite may contribute to allergy symptom relief by inhibiting leukotriene production, but not histamine release.
