Institute of Pharmacology, Catholic University School of Medicine, Largo F. Vito, 1, 00168 Rome, Italy.
Neurosci Lett. 2012 Jun 19;518(2):101-5. doi: 10.1016/j.neulet.2012.04.062. Epub 2012 May 2.
Reactive oxygen and reactive nitrogen species oxidize and nitrate DNA, lipid and proteins thus leading to neuronal death. Both endogenous and dietary antioxidants were shown to afford neuroprotection either by scavenging free radicals or inducing antioxidant enzymes. That said, the differential contribution of endogenous versus nutritional antioxidants to prevent neurodegeneration is still debated. In this study the free radical scavenging activity of two endogenous antioxidants, such as bilirubin and its precursor biliverdin, was compared with that of the dietary antioxidant alpha-tocopherol in rat brain microsomes exposed to peroxyl radical or peroxynitrite in vitro. Bilirubin and biliverdin (1-200 μM) inhibited both peroxyl radical- and peroxynitrite-dependent lipid peroxidation with a greater potency and efficacy than alpha-tocopherol. However, both BV and BR displayed greater potency and efficacy in preventing peroxynitrite- than peroxyl radical-induced lipid peroxidation. The greater antioxidant effect of both bilirubin and biliverdin than alpha-tocopherol was also confirmed against peroxyl radical- and peroxynitrite-induced protein oxidation. In conclusion, both bilirubin and biliverdin exhibited a greater antioxidant activity than alpha-tocopherol in preventing oxidative stress damage in rat brain.
活性氧和活性氮物种会氧化和硝化 DNA、脂质和蛋白质，从而导致神经元死亡。内源性和膳食抗氧化剂都被证明可以通过清除自由基或诱导抗氧化酶来提供神经保护。也就是说，内源性和营养抗氧化剂对预防神经退行性变的贡献差异仍存在争议。在这项研究中，比较了两种内源性抗氧化剂——胆红素及其前体胆绿素——与膳食抗氧化剂α-生育酚在大鼠脑微粒体中清除过氧自由基或过氧亚硝酸盐的自由基清除活性。胆红素和胆绿素（1-200 μM）抑制了过氧自由基和过氧亚硝酸盐依赖性脂质过氧化，其效力和效力均大于α-生育酚。然而，BV 和 BR 在预防过氧亚硝酸盐诱导的脂质过氧化方面比过氧自由基具有更高的效力和效力。胆红素和胆绿素比α-生育酚具有更强的抗氧化作用，这一点也得到了过氧自由基和过氧亚硝酸盐诱导的蛋白质氧化的证实。总之，胆红素和胆绿素在预防大鼠脑氧化应激损伤方面表现出比α-生育酚更强的抗氧化活性。
