Background: Modifi cation of proteins may play a central role in a great variety of pathophysiological processes.It has already been ascertained that raloxifene (LY 139481), a selective estrogen receptor modulator (SERM), is an effective inhibitor of LDL oxidation. herefore, we examined potential anti-oxidant activity related to the oxidation of the glycoprotein fi brinogen.Materials/Methods: In this study we investigated whether raloxifene is able to inhibit in vitro iron-mediated oxidation of fi brinogen. We tested three different concentrations of raloxifene (5, 10, and 125 µM) corresponding to the usual dosage in postmenopausal women of between 10 and 300 mg/day, choosing two incubation periods (60 and 120 min).Results: Our results in the examined dose-range provide no evidence that raloxifene is able to prevent ironinduced fi brinogen oxidation in vitro. Considering the chemical structure of the glycoprotein fi - brinogen, it is likely that raloxifene is unable to attack a particle without lipophilic properties, although the site of its action on LDL is still unknown.Conclusions: Our data suggest that raloxifene, in contrast to its effect on LDL, lacks the capability to inhibit the oxidation of fi brinogen. The biological relevance of this fi nding still needs to be assessed in vivo.

Keywords: Fibrinogen - chemistry, Raloxifene - chemistry, Antioxidants - chemistry, Fibrinogen - chemistry, Iron - chemistry, Oxidation-Reduction, Raloxifene - chemistry