[Ketanserin as antioxidant]

Free radicals have been related to the pathogenesis of some cardiovascular diseases. Several drugs used to treat these diseases were shown to have antioxidant properties. Our purpose was to evaluate if ketanserin, a selective S2 receptor antagonist with proven antihypertensive efficacy and which beneficially affects hemorheology, also is able to inhibit lipid peroxidation. Lipid peroxidation was induced in different biological systems in vitro and evaluated by the formation of thiobarbituric acid-reactive products. Ketanserin 50 microM inhibited copper-dependent lipid peroxidation in human red-cell suspensions by 40.8% and the subsequent hemolysis by 57,3%. It was less efficient in inhibiting hydrogen peroxide-dependent lipid peroxidation and hemolysis in the same system. Ketanserin 100 microM inhibited lipid peroxidation induced by a mixture of copper(II) and hydrogen peroxide in hepatic microsomal suspensions and in brain total homogenates by 86.2% and 56.7%, respectively. These results proved an antioxidant effect for ketanserin which was unknown, although its therapeutic relevance remains undetermined.