Protective effects of icariin on human umbilical vein endothelial cell injury induced by H2O2 in vitro

Icariin is a flavonoid isolated from Epimedium and is considered to be the major pharmacologic active component of Epimedii Herba. In the present investigation, we studied and confirmed the protective activity of icariin on H2O2-induced injury in human umbilical vein endothelial cell line: ECV-304. Eighteen-hour treatment with 750 mu mol(-1) H2O2 significantly decreased the viability of ECV-3114 cells, which was accompanied with apparent apoptotic features, including distinct cell morphological alteration and the increase of caspase-3 expression. In addition, it is observed that H2O2 increased the amounts of malondialdenhyde (MDA) and the dehydrogenase (LDH). and decreased the content of nitric oxide (NO) in ECV-304 cells. However, pretreatment with 0.1-50 mu mol(-1) icariin resulted in a significant recovery from H2O2-induced cell apoptosis. Also, it decreased other H=O=-induced damage in a concentration-dependent manner. Furthermore, pretreatment with icariin decreased the expression of caspase-3, which was known to be involved as a key rule executor in H2O2-induced cell apoptosis. The endothelial cells apoptosis were detected by acridine orange/ethidiutn bromide (AO/EB) dual staining as well its flow cytornetry. and the expression of pro-apoptotic factor caspase-3 were detected by immunocytochemical method. Taken together, these data suggest that protective effect:; of icariin against oxidative injuries of ECV-304 cells may be achieved via decreasing of caspase expression. (c) 2005 Elsevier Ltd. All rights reserved.