Cheng Z J, Kuo S C, Chan S C, Ko F N, Teng C M
Pharmacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Rd., Sect. 1, Taipei, Taiwan.
Biochim Biophys Acta. 1998 Jun 15;1392(2-3):291-9. doi: 10.1016/s0005-2760(98)00043-5.
The antioxidant properties of butein, isolated from Dalbergia odorifera T. Chen, were investigated in this study. Butein inhibited iron-induced lipid peroxidation in rat brain homogenate in a concentration-dependent manner with an IC50, 3.3+/-0.4 microM. It was as potent as alpha-tocopherol in reducing the stable free radical diphenyl-2-picrylhydrazyl (DPPH) with an IC0.200, 9.2+/-1.8 microM. It also inhibited the activity of xanthine oxidase with an IC50, 5.9+/-0.3 microM. Besides, butein scavenged the peroxyl radical derived from 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH) in aqueous phase, but not that from 2,2-azobis(2, 4-dimethylvaleronitrile) (AMVN) in hexane. Furthermore, butein inhibited copper-catalyzed oxidation of human low-density lipoprotein (LDL), as measured by conjugated dienes and thiobarbituric acid-reactive substance (TBARS) formations, and electrophoretic mobility in a concentration-dependent manner. Spectral analysis revealed that butein was a chelator of ferrous and copper ions. It is proposed that butein serves as a powerful antioxidant against lipid and LDL peroxidation by its versatile free radical scavenging actions and metal ion chelation.
本研究对从降香檀中分离得到的紫铆因的抗氧化特性进行了研究。紫铆因以浓度依赖的方式抑制大鼠脑匀浆中铁诱导的脂质过氧化，其半数抑制浓度（IC50）为3.3±0.4微摩尔。在还原稳定自由基二苯基-2-苦基肼（DPPH）方面，它与α-生育酚的效力相当，IC0.200为9.2±1.8微摩尔。它还以IC50为5.9±0.3微摩尔的浓度抑制黄嘌呤氧化酶的活性。此外，紫铆因能清除水相中由2,2-偶氮二异丁脒二盐酸盐（AAPH）产生的过氧自由基，但不能清除己烷中由2,2-偶氮二（2,4-二甲基戊腈）（AMVN）产生的过氧自由基。此外，通过共轭二烯和硫代巴比妥酸反应性物质（TBARS）的形成以及电泳迁移率测定，紫铆因以浓度依赖的方式抑制铜催化的人低密度脂蛋白（LDL）氧化。光谱分析表明，紫铆因是亚铁离子和铜离子的螯合剂。有人提出，紫铆因通过其多种自由基清除作用和金属离子螯合作用，作为一种强大的抗氧化剂来对抗脂质和LDL过氧化。
