Ability of Water-Soluble Biosubstances to Eliminate Hydroxyl and Superoxide Radicals Examined by Spin-Trapping ESR Measurements: Two-Dimensional Presentation of Antioxidative Ability

作者：Nakajima Akira^*; Sakurai Yasuhiro; Matsuda Emiko; Masuda Yukari; Naganobu Yoshiko; Tajima Kunihiko; Sameshima Hiroshi; Ikenoue Tsuyomu

来源：Bioscience Biotechnology and Biochemistry, 2013, 77(2): 324-331.

DOI：10.1271/bbb.120749

• antioxidative ability
• free-radical elimination
• hydroxyl radical
• superoxide radical
• spin-trapping

The hydroxyl- and superoxide-radical-eliminating ability of water-soluble biosubstances was examined by ESR combined with the spin-trapping method, indicating a median inhibitory dose, ID50h (mm) and id(50)(h) (mg/mL) for the hydroxyl radical, and ID50s (mm) and id(50)(s) (mg/mL) for the superoxide radical. Both the 1/[ID50h (mm)] and 1/[ID50s (mm)] values of selected biosubstances were linearly related to the second-order rate constant, k(2) (M-1 s(-1)), defined for the reaction between biosubstances and the radicals in a logarithmic presentation. The result indicates that ID50h (mm) and ID50s (mm) are suitable parameters for both types of radical-eliminating ability. The obtained results are depicted two-dimensionally, taking id(50)(h) (mg/mL) as the abscissa and id(50)(s) (mg/mL) as the ordinate in the ROS inhibitory diagram. The biosubstances tested were assigned to five separate areas characterized by their functional groups on the diagram. The obtained ROS inhibitory diagram indicates the possibility for screening appropriate antioxidants.

• 出版日期2013-2