Ubeda A, Montesinos C, Payá M, Alcaraz M J
Departamento de Farmacologia, Facultad de Farmacia, Valencia, Spain.
Free Radic Biol Med. 1993 Aug;15(2):159-67. doi: 10.1016/0891-5849(93)90055-y.
The scavenging and iron-reducing properties of a series of benzylisoquinolines of natural and synthetic origin have been studied. Bulbocapnine, boldine, glaucine, and stepholidine acted as scavengers of hydroxyl radical in the deoxyribose degradation by Fe(3+)-EDTA + H2O2. On the contrary, laudanosoline, apomorphine, protopapaverine, anonaine, and tetrahydroberberine increased deoxyribose degradation by a mechanism related to generation of superoxide anion. Only apomorphine had a stimulating effect in the system using citrate instead of ethylenediaminetetraacetic acid (EDTA) as well as in the absence of chelator. Apomorphine also stimulated DNA damage by Cu2+. The iron-ion reducing ability of apomorphine and laudanosoline was confirmed using cytochrome c. Both compounds scavenged peroxyl radicals in an aqueous medium, while in Fe(3+)-induced microsomal lipid peroxidation apomorphine acted as an inhibitor and laudanosoline stimulated the process. It is suggested that in microsomes the chain-breaking antioxidant properties of apomorphine overcome its possible influence on redox cycling of iron, or prooxidant properties.
对一系列天然和合成来源的苄基异喹啉的清除和铁还原特性进行了研究。紫堇碱、去氢骆驼蓬碱、青藤碱和千金藤啶碱在Fe(3+)-EDTA + H2O2引发的脱氧核糖降解过程中作为羟基自由基的清除剂。相反，劳丹索碱、阿扑吗啡、原阿片碱、去甲乌药碱和四氢小檗碱通过与超氧阴离子生成相关的机制增加了脱氧核糖的降解。只有阿扑吗啡在使用柠檬酸盐代替乙二胺四乙酸（EDTA）的体系中以及在没有螯合剂的情况下具有刺激作用。阿扑吗啡还能促进Cu2+对DNA的损伤。使用细胞色素c证实了阿扑吗啡和劳丹索碱的铁离子还原能力。两种化合物在水介质中都能清除过氧自由基，而在Fe(3+)诱导的微粒体脂质过氧化过程中，阿扑吗啡起抑制剂作用，劳丹索碱则促进该过程。有人认为，在微粒体中，阿扑吗啡的断链抗氧化特性克服了其对铁的氧化还原循环可能产生的影响，或其促氧化特性。
