Erycristagallin, a pterocarpene isolated from Erythrina mildbraedii, was tested in vitro for its
antioxidant properties on the stable 2,2-diphenyl-1-pycryl-hydrazyl (DPPH)
free radical and on the
arachidonic acid metabolism. In addition,
erycristagallin was tested on different experimental models of
inflammation, such as the acute and chronic
inflammation induced by the application of 12-O-tetradecanoylphorbol 13-acetate (TPA) on mice and the
phospholipase A(2)-induced mouse paw oedema test. In the
carrageenan-induced mouse paw oedema test, the
ethyl acetate extract obtained from E. mildbraedii showed anti-inflammatory activity, and
erycristagallin was isolated as the active principle. In vivo,
erycristagallin significantly inhibited the
phospholipase A(2)-induced mouse paw oedema as well as the mouse ear oedema induced by TPA (ID(50)<10 microg/ear). Moreover, it significantly reduced the chronic
inflammation and leukocyte infiltration induced by repeated application of TPA. In vitro,
erycristagallin inhibited the
arachidonic acid metabolism via the
5-lipoxygenase pathway in rat polymorphonuclear leukocytes (IC(50)=23.4 microM), but had no effect on
cyclooxygenase-1 metabolism in human platelets, while showing
antioxidant activity in the DPPH test. As with other phenolics, the anti-inflammatory activity of
erycristagallin may be based on its capacity to inhibit the
arachidonic acid metabolism via the
5-lipoxygenase pathway.