Zai-Qun Liu, xueyue luo, Yunkuo Sun
Dec 1, 2004
Citations
0
Influential Citations
50
Citations
Quality indicators
Journal
Journal of Pharmacy and Pharmacology
Abstract
Icariin (2‐(4′‐methoxyl phenyl)‐3‐rhamnosido‐5‐hydroxyl‐7‐glucosido‐8‐(3′‐methyl‐2‐butylenyl)‐4‐chromanone) is the major component in Herba Epimedii used in traditional Chinese medicine for the treatment of atherosclerosis. This work focuses on the antioxidative effect of icariin on free‐radical‐induced haemolysis of human erythrocytes, in which the initial free radical derives from the decomposition of 2,2′‐azobis(2‐amidinopropane hydrochloride) (AAPH) at physiological temperature. To reveal the structure‐activity relationship of icariin, the antioxidant effects of two structural analogues of icariin, acacetin (2‐(4′‐methoxylphenyl)‐5,7‐dihydroxylchromone) and norwogonin (2‐phenyl‐5,7,8‐trihydroxylchromone), on the same experimental system were examined as well. It was found that all these chromone derivatives (Chm‐OHs) dose‐dependently protected human erythrocytes against free‐radical‐induced haemolysis. The order of antioxidative activity was norwogonin>acacetin>icariin by the analysis of the relationship between the concentration of Chm‐OHs and the prolongation percentage of the lag time of haemolysis (PP%). It was also proved that the phenyl hydroxyl group attached to the chromone ring at 7‐position cannot trap the free radical. On the contrary, phenyl hydroxyl groups at the 5‐ and 8‐position in norwogonin made it a significant antioxidant in AAPH‐induced haemolysis. The more hydroxyl groups attached to the chromone ring, the higher the antioxidative activity in protecting erythrocytes against free‐radical‐induced peroxidation.