Oleuropein evaluated in vitro and in vivo as an antioxidant

Oleuropein is a phenolic compound extracted from the leaves of Olea europaea. The antioxidant activity of this natural product has been evaluated in vitro and in vivo by means of a chemiluminescent assay, based on a luminol-horseradish peroxidase p-iodophenol O2 mediated light emission system. In vitro, oleuropein had a remarkable antioxidant activity. Serum samples obtained from treated animals exhibited an antioxidant activity comparable to controls. Bile samples obtained from the same treated animals showed a significant inhibition (90%) of the light emission in the chemiluminescent assay, when compared with the control sample. © 1998 John Wiley & Sons, Ltd.