ILEX AQUIFOLIUM - PROTECTION AGAINST ENZYMATIC AND NONENZYMATIC LIPID-PEROXIDATION

The ethanolic extract of Ilex aquifolium L. (Aquifoliaceae) concentrat ion-dependently inhibited leukotriene B-4 biosynthesis in isolated bov ine PMNL with an IC50 value of about 60 mu g/ml, whereas the effect on epidermal 12(S)-HETE biosynthesis was much less pronounced. The extra ct also inhibited the non-enzymatic, peroxyl radical-stimulated lipid peroxidation in model membranes and was further a scavenger of the iro n-dependent generation of hydroxyl radicals from hydrogen peroxide as determined by protection against deoxyribose degradation. While inhibi tion of leukotriene biosynthesis was not mediated by its known phenoli c constituents such as hyperoside, rutoside, and chlorogenic acid, the se compounds were responsible for the inhibitory effects of I. aquifol ium against nonenzymatic lipid peroxidation and deoxyribose degradatio n.