Saito Keita, Kohno Masahiro, Yoshizaki Fumihiko, Niwano Yoshimi
New Industry Creation Hatchery Center, Tohoku University, Aramaki, Sendai, Japan.
Plant Foods Hum Nutr. 2008 Jun;63(2):65-70. doi: 10.1007/s11130-008-0071-2. Epub 2008 Jan 31.
To search for edible herbal extracts with potent antioxidant activity, we conducted a large scale screening based on the superoxide scavenging activity. That is, scavenging activity against superoxide anions were extensively screened from ethanol extracts of approximately 1,000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method. Among them we chose four edible herbal extracts with prominently potent ability to reduce the signal intensity of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OOH, a spin adduct formed by DMPO and superoxide anion. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit), and are allowed to be used as foodstuffs according to the Japanese legal regulation. The ESR-spin trapping method coupled with steady state kinetic analysis showed that all of the four extracts directly scavenge superoxide anions, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. Furthermore, polyphenol determination indicates that the activity is at least in part attributable to polyphenols. These results with such large scale screening might give useful information when choosing a potent antioxidant as a foodstuff.
为了寻找具有强大抗氧化活性的可食用草药提取物，我们基于超氧化物清除活性进行了大规模筛选。也就是说，通过应用电子自旋共振（ESR）-自旋捕获法，从大约1000种草药的乙醇提取物中广泛筛选了对超氧阴离子的清除活性。其中，我们选择了四种具有显著强大能力降低5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）-OOH信号强度的可食用草药提取物，DMPO-OOH是DMPO与超氧阴离子形成的自旋加合物。它们分别是石榴（果皮）、丁香（花蕾）、芒果（果核）和余甘子（果实）的提取物，根据日本法律法规允许用作食品。ESR-自旋捕获法结合稳态动力学分析表明，这四种提取物均能直接清除超氧阴离子，且任何一种提取物的超氧化物清除潜力与L-抗坏血酸相当。此外，多酚测定表明该活性至少部分归因于多酚。如此大规模筛选的结果可能会在选择一种强大的抗氧化剂作为食品时提供有用信息。
