Effects of valsartan and 17 beta-estradiol on the oxidation of low-densitylipoprotein in vitro

Background The 'sartans' are antagonists of the angiotensin type 1 (AT(1)) receptor that are mainly used for treatment of hypertension. Little is know n about AT(1)-independent effects of these substances and interactions with other drugs used for prevention of cardiovascular diseases. Postmenopausal estradiol-replacement therapy has been shown to exert beneficial antiather o-sclerotic properties by inhibiting oxidation of low-density lipoprotein ( LDL). Objective In the present study, the effects of valsartan alone and in combi nation with 17 beta-estradiol on the oxidation of isolated human LDL were i nvestigated. Methods Oxidation of LDL, which was triggered by copper (II) chloride, was monitored spectrometrically at 234 nm. The test substances were added in vi tro. Results Valsartan alone increased the duration of resistance of LDL to oxid ation by 75.3 +/- 5.7 min at 5 mu mol/l and by 138.2 +/- 8.1 min at 10 mu m ol/l. 17 beta-estradiol alone delayed the onset of oxidation of LDL by 75.7 +/- 5.1 min at 1 mu mol/l. With the combination of 5 and 10 mu mol/l valsa rtan with 1 mu mol/l estradiol the time to onset of oxidation of LDL was in creased by 142.8 +/- 4.9 and 215.3 +/- 6.9 min, respectively. Conclusions There has been demonstrated an antioxidative effect of valsarta n that was additive to that of 17 beta-estradiol. Thus this combination has the potential to be useful in the treatment of postmenopausal women with h ypertension. Coron Artery Dis 11:347-349 (C) 2000 Lippincott Williams & Wil kins.