Okada Y, Okajima H
School of Health Sciences, Kyorin University, Hachioji, Tokyo, Japan.
Redox Rep. 2001;6(2):117-22. doi: 10.1179/135100001101536120.
The antioxidant activity of capsaicin (CAP) was measured in the oxidation of methyl linoleate (ML) in homogeneous solution, of ML micelles in aqueous dispersions and also of soybean phosphatidylcholine liposomal membrane, and was compared to that of alpha-tocopherol (alpha-TOH) which is one of the most important antioxidants in vivo. The reactivity of CAP toward galvinoxyl (a model phenoxyl radical) in acetonitrile solution was found to be much smaller than that of alpha-TOH, suggesting that the radical scavenging activity of CAP is much weaker than that of alpha-TOH. In fact, in homogeneous acetonitrile solution where the antioxidant activity is determined primarily by the chemical activity of the antioxidant toward peroxyl radicals, CAP inhibited the oxidation of ML much less efficiently than alpha-TOH and a clear induction period was not observed. The antioxidant activity of CAP was found to be about 60 times smaller than that of alpha-TOH in homogeneous solution. However, in micelle oxidation, the difference in antioxidant activity of the two antioxidants was much smaller than in homogeneous solution. Furthermore, in the membrane, CAP inhibited the oxidation almost as effectively as alpha-TOH. These results suggest that CAP can act as an antioxidant in the biomembrane.
在均相溶液中、水分散体系中的亚油酸甲酯（ML）胶束以及大豆磷脂酰胆碱脂质体膜中，测定了辣椒素（CAP）的抗氧化活性，并将其与体内最重要的抗氧化剂之一α-生育酚（α-TOH）的抗氧化活性进行了比较。研究发现，在乙腈溶液中，CAP与加尔文氧基（一种苯氧自由基模型）的反应活性远低于α-TOH，这表明CAP的自由基清除活性远低于α-TOH。事实上，在抗氧化活性主要由抗氧化剂对过氧自由基的化学活性决定的均相乙腈溶液中，CAP抑制ML氧化的效率远低于α-TOH，且未观察到明显的诱导期。在均相溶液中，CAP的抗氧化活性约为α-TOH的1/60。然而，在胶束氧化过程中，两种抗氧化剂的抗氧化活性差异远小于均相溶液中的差异。此外，在膜中，CAP抑制氧化的效果几乎与α-TOH相同。这些结果表明，CAP可以在生物膜中起到抗氧化剂的作用。
