tailieunhanh - Protective action of ampelopsis cantoniensis and its major constituent – myricetin against LDL oxidation

It is widely accepted that oxidative modification of lowdensity lipoprotein (LDL) plays a pivotal role in the initiation and development of atherosclerosis. In the present study, we found that the MeOH and H2O extracts of the plant Ampelopsis cantoniensis, and its main constituent, myricetin, possessed significant protective effects on LDL oxidation induced by either a metal ion (Cu2+) or a free radical (AAPH). | Journal of Chemistry Vol. 45 6 P. 768 - 771 2007 PROTECTIVE ACTION OF AMPELOPSIS CANTONIENSIS AND ITS MAJOR CONSTITUENT - MyRICETIN AGAINST LDL OXIDATION Received 16 January 2007 DO THI HA1 2 PHUONG THIEN THUONG1 NGUyEN Duy THUAN2 1 College of Pharmacy Chungnam National University Daejeon 305-764 South Korea 2Department of Phytochemistry National Institute of Medicinal Materials SUMMARy It is widely accepted that oxidative modification of lowdensity lipoprotein LDL plays a pivotal role in the initiation and development of atherosclerosis. In the present study we found that the MeOH and H2O extracts of the plant Ampelopsis cantoniensis and its main constituent myricetin possessed significant protective effects on LDL oxidation induced by either a metal ion Cu2 or a free radical AAPH . All of these MeOH ex. H2O ex. and myricetin exhibited higher antioxidant activity than that of a-tocopherol in a dose dependent manner and especially myricetin disclosed stronger inhibitory effect than that of -catechin a major component of green tea. The result suggests that the decoction of the medicinal plant che day could be used beneficially as a remedy to prevent the LDL oxidation involved in the atherosclerotic lesion. I - INTRODUCTION Atherosclerosis a disease of arteries characterized by a local thickening of vessel wall that develops in the inner coat tunica intima is the leading cause of death in the industrial world. It has been recognized that there are many risk factors that may cause atherosclerosis in human 1 . Among them the oxidative modification of LDL in artery wall is generally accepted to play a key role in the initiation and development of atherosclerosis 2 . Hence inhibitory action of LDL oxidation by supplemental antioxidants is considered as an attractive therapeutic strategy to prevent atherosclerosis and other related diseases 3 . A. cantoniensis Hook. Arn. Planch Vitaceae is distributed in China India Japan Vietnam normally called Canton ampelopsis. This is