α-硫辛酸和二氢硫辛酸的抗氧化作用

采用多种化学发光体系和比色体系研究了氧化型硫辛酸——α-硫辛酸（α-lipoic acid, LA）和还原型硫辛酸——二氢硫辛酸（dihydrolipoic acid, DHLA）直接清除活性氧、抗脂质过氧化以及对&;#8226;OH引起的DNA氧化损伤的保护作用.实验发现，LA和DHLA能有效清除相应体系中的活性氧过氧化氢（H₂O₂）、羟自由基（&;#8226;OH）、过氧亚硝基阴离子（ONOO^-）和二苯代苦味肼基自由基（DPPH&;#8226; ），能显著抑制脂质过氧化，并对&;#8226;OH引起的DNA氧化损伤有良好的保护作用，而DHLA还可以有效清除超氧阴离子自由基（O&;#8226;₂^-）.这些结果提示，LA和DHLA都是良好的抗氧化剂，但相比之下DHLA的抗氧化能力要显著强于LA.本研究为LA和DHLA保健和药用价值的进一步开发，提供了自由基生物学方面的依据.

Studies on the Antioxidation Effects of Alpha-Lipoic Acid and Dihydrolipoic Acid(Chinese)

Lipoic acid(LA) widely exists in all kinds of cells. It can be converted to dihydrolipoic acid (DHLA) in mammalian cell. The ability of alpha-LA and DHLA to scavenge reactive oxygen species and prevent DNA from oxidative damage by &;#8226;OH was evaluated using chemiluminescence systems and colorimetric systems. The experiments show that LA and DHLA can directly scavenge &;#8226;OH、H₂O₂、ONOO^-and DPPH&;#8226; ，effectively inhibit lipid peroxidation and DNA oxidative damage by &;#8226;OH； DHLA can also effectively scavenge O&;#8226;₂^-. These results indicate that both LA and DHLA are effective antioxidants and the anti-oxidative ability of DHLA is obviously stronger than that of LA. The present investigation can provide new free radical biological data for the further study on the medical and health-care applications of LA and DHLA.