Federal University of Rio Grande do Sul, Brazil; Serviço de Genética Médica, HCPA, Ramiro Barcelos 2350, Porto Alegre, RS 90035-903, Brazil.
Gene. 2014 Jan 10;533(2):469-76. doi: 10.1016/j.gene.2013.10.017. Epub 2013 Oct 19.
In recent years increasing evidence has emerged suggesting that oxidative stress is involved in the pathophysiology of a number of inherited metabolic disorders. However the clinical use of classical antioxidants in these diseases has been poorly evaluated and so far no benefit has been demonstrated. l-Carnitine is an endogenous substance that acts as a carrier for fatty acids across the inner mitochondrial membrane necessary for subsequent beta-oxidation and ATP production. Besides its important role in the metabolism of lipids, l-carnitine is also a potent antioxidant (free radical scavenger) and thus may protect tissues from oxidative damage. This review addresses recent findings obtained from patients with some inherited neurometabolic diseases showing that l-carnitine may be involved in the reduction of oxidative damage observed in these disorders. For some of these diseases, reduced concentrations of l-carnitine may occur due to the combination of this compound to the accumulating toxic metabolites, especially organic acids, or as a result of protein restricted diets. Thus, l-carnitine supplementation may be useful not only to prevent tissue deficiency of this element, but also to avoid oxidative damage secondary to increased production of reactive species in these diseases. Considering the ability of l-carnitine to easily cross the blood-brain barrier, l-carnitine supplementation may also be beneficial in preventing neurological damage derived from oxidative injury. However further studies are required to better explore this potential.
近年来，越来越多的证据表明氧化应激与许多遗传性代谢紊乱的病理生理学有关。然而，这些疾病中经典抗氧化剂的临床应用评价不佳，迄今为止尚未证明其有益。左旋肉碱是一种内源性物质，作为脂肪酸载体穿过线粒体内膜，这对于随后的β氧化和 ATP 生成是必需的。除了在脂质代谢中的重要作用外，左旋肉碱也是一种有效的抗氧化剂（自由基清除剂），因此可能保护组织免受氧化损伤。这篇综述介绍了一些遗传性神经代谢疾病患者的最新发现，表明左旋肉碱可能参与了这些疾病中观察到的氧化损伤的减少。对于其中一些疾病，左旋肉碱的浓度降低可能是由于该化合物与积累的有毒代谢物（特别是有机酸）结合，或者由于蛋白质限制饮食所致。因此，左旋肉碱的补充不仅可以预防组织中这种元素的缺乏，还可以避免由于这些疾病中活性物质产生增加而导致的氧化损伤。考虑到左旋肉碱能够轻易穿过血脑屏障，左旋肉碱的补充也可能有益于预防由氧化损伤引起的神经损伤。然而，需要进一步的研究来更好地探索这种可能性。
