Anti-inflammatory action of legume isoflavonoid sophoricoside through inhibition on cyclooxygenase-2 activity.

Soy is a main source of isoflavonoids which are of high dietary intake for the oriental population. In this study, the anti-inflammatory action of sophoricoside, an isoflavone glycoside isolated from immature fruits of Sophora japonica L. (Leguminosae), has been demonstrated. When administered orally at > 100 mg/kg or injected intravenously at > 10 mg/kg, sophoricoside showed significant reduction of carrageenin-induced paw edema in mice. Sophoricoside has been identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an IC50 value of 3.3 microM.